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Consumption of Chinese herbal medicines during pregnancy and postpartum: A prospective cohort study in China
Midwifery ∎ (∎∎∎∎) ∎∎∎–∎∎∎
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Consumption of Chinese herbal medicines during pregnancy and postpartum: A prospective cohort study in China Li Tang, PhD (Postdoctoral Fellow)a,b,n, Andy H. Lee, PhD (Professor)b, Colin W. Binns, PhD (Professor)b, Yer Van Hui, PhD (Professor)a,c, Kelvin K.W. Yau, PhD (Professor)a a
Department of Management Sciences, City University of Hong Kong, Kowloon, Hong Kong School of Public Health, Curtin University, Perth, WA, Australia c Hang Seng Management College, New Territories, Hong Kong b
art ic l e i nf o
a b s t r a c t
Article history: Received 18 August 2015 Received in revised form 24 October 2015 Accepted 10 November 2015
Objective: to investigate usage patterns and factors associated with maternal consumption of Chinese herbal medicines in China. Design: prospective cohort study. Information on the use of Chinese herbal medicines was collected from mothers by personal interview at hospital discharge and followed up by telephone at one, three and six months postpartum. Setting: seven hospitals in Jiangyou, Sichuan Province of China. Participants: 695 mothers who gave birth to a singleton infant. Measurements: prevalence, type, frequency and duration of herbal medicine usage. Logistic mixed regression analyses were performed to determine factors affecting the use. Findings: a total of 43.5% and 45.0% of mothers consumed Chinese herbal medicines during pregnancy and postpartum, respectively. Angelica sinsensis was the most popular herbal medicine among the participants (pregnancy 28.8%, postpartum 26.8%). Although herbal medicines were taken more regularly by postpartum users, the median usage duration varied from two to three months during pregnancy but 1–1.6 months postpartum. The majority of users (pregnancy 42.9%, postpartum 55.1%) were advised by their mother or mother-in-law to take Chinese herbal medicines. Antenatal alcohol drinking (adjusted odds ratio 2.75, 95% confidence interval 1.01–7.53) was associated with a marginally higher prevalence of herbal consumption during pregnancy, whereas mothers with a lower family income (adjusted odds ratio 1.52, 95% confidence interval 1.12–2.04) were more likely to consume Chinese herbal medicines in the postpartum period. Key conclusions and implications for practice: consumption of Chinese herbal medicines appears to be prevalent among Chinese mothers, especially those drinking alcohol whilst pregnant and women from a lower income household. Maternity health professionals need to be aware of the lack of evidence to support the use of Chinese herbal medicines during pregnancy and postpartum, and to provide their clients with scientifically based advice regarding herbal medicine use. & 2015 Elsevier Ltd. All rights reserved.
Keywords: Chinese herbal medicine Pregnancy Postpartum China
Introduction Herbal medicines are often regarded as ‘natural’ and therefore ‘safe’, although there is little scientific basis for this belief. Worldwide, studies have documented that maternal consumption of n Corresponding author at: Department of Management Sciences, G7502, Green Zone, Academic 1, Tat Chee Avenue, City University of Hong Kong, Kowloon, Hong Kong. E-mail addresses: [email protected] (L. Tang), [email protected] (A.H. Lee), [email protected] (C.W. Binns), [email protected] (Y.V. Hui), [email protected] (K.K.W. Yau).
herbal medicines is common during pregnancy and the postpartum period (Rahman et al., 2008; Chuang et al., 2009; Holst et al., 2009; Hall et al., 2011; Nordeng et al., 2011). The reported prevalence of herbal intake during pregnancy ranged from 12% to 44% in Australia (Pinn and Pallett, 2002; Forster et al., 2006; Frawley et al., 2013; Kennedy et al., 2013) and from 36% to 58% in European countries (Nordeng and Havnen, 2004; Holst et al., 2009; Nordeng et al., 2011). The herbal consumption rate among Asian women was similarly high at 51% in Malaysia and 40% in Palestine (Rahman et al., 2008; Al-Ramahi et al., 2013). Recent studies of Chinese communities suggested that 34% of Taiwanese women consumed at
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Please cite this article as: Tang, L., et al., Consumption of Chinese herbal medicines during pregnancy and postpartum: A prospective cohort study in China. Midwifery (2015), http://dx.doi.org/10.1016/j.midw.2015.11.010i
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least one type of Chinese herbal medicine during pregnancy (Chuang et al., 2009), and the corresponding rate was 56% in Hong Kong (Ong et al., 2005). With regard to herbal medicine usage after childbirth, data were scarce and the published prevalence appeared to vary widely between societies. For instance, nearly 14% of 3354 Canadian women in a survey reported herbal products consumption during their first year after childbirth (Moussally et al., 2009), much lower than the prevalence of 88% (within six months postpartum) observed in a population-based study from Taiwan (n¼21,248) (Chuang et al., 2009). Different herbal medicines are used between ethnic groups due to the diversity in cultural background and traditional beliefs (Rahman et al., 2008; Chuang et al., 2009; Nordeng et al., 2011). Their potential adverse effects on mother and fetus, such as hepatotoxic and carcinogenic effects, fetal distress, low birthweight and birth defects, have been documented extensively (Mabina et al., 1997; Ernst, 2002; Chuang et al., 2006; Wang et al., 2013). Nevertheless, very few published randomised clinical trials have evaluated the therapeutic effects of herbal products (Guo et al., 2007), and even less data are available concerning their efficacy for pregnant or lactating women (Holst et al., 2011; Smeriglio et al., 2014). Factors that influence maternal consumption of herbal medicines also vary across populations. For example, a survey in the United Kingdom revealed that women who had been pregnant before and those with a university degree tended to use herbal remedies during pregnancy (Holst et al., 2009), yet primiparous mothers in Australia were more likely to take herbal supplements during pregnancy than their multiparous counterparts (Forster et al., 2006). Moreover, while an inverse association was found between education and use of Chinese herbal medicines among Hong Kong pregnant women (Ong et al., 2005), higher educational level was linked to a higher prevalence of herbal consumption by pregnant and postnatal mothers in Taiwan (Chuang et al., 2009). Traditional Chinese medicine has been practiced in China since ancient times, with Chinese herbal medicine being the most frequently used category (Liu et al., 2012). However, a comprehensive literature search found only one published study documenting maternal use of Chinese herbal medicines in mainland China. This cross-sectional survey of 306 women, conducted in the south eastern city of Hangzhou, reported that one in five women used Chinese herbal medicines during pregnancy, childbirth or within 42 days postpartum (Zeng et al., 2014). In view of the lack of epidemiological information on herbal consumption, the present study aimed to determine the prevalence and pattern of Chinese herbal medicines usage by Chinese women during pregnancy and the first six months postpartum, and to identify the commonly consumed herbal medicines. Factors associated with Chinese herbal usage, as well as their sources of recommendation, were also investigated.
Methods Study design and setting A prospective cohort study was undertaken during 2010–2011 in Jiangyou, Sichuan Province of China. Sichuan is a large province in Western China with a population of 80 million people. According to its provincial Health and Family Planning Commission, the hospital delivery rate was approximately 95% in 2011. Jiangyou, a typical county-level town with a population of 880,000, is located 160 km north of the provincial capital city Chengdu. Between March and November 2010, mothers aged Z18 years, who gave birth to a singleton infant at one of the seven hospitals in Jiangyou, were invited to participate in this study
before discharge. Exclusion criteria were unable to answer the questions due to limited understanding or deemed unwell to participate as advised by hospital health professionals. This study planned to recruit a sample of 650 women at baseline. The sample size was calculated by assuming a prevalence of herbal consumption between 51% and 60% in the first six months postpartum (at 5% level of significance) and accounting for a 10% non-response rate and a 20% drop-out rate. Of the total 723 eligible women invited to participate, 695 consented, yielding a response rate of 96%. Questionnaire and procedure At discharge, all consented women were interviewed face-toface by the first author or one of the trained hospital staff using a structured questionnaire. Chinese herbal medicine was defined as a locally available herb (the whole or part of a plant) or herbal processed product which had been empirically known to be effective in treating disorders and maintaining good health. Information on the frequency and duration of usage was recorded for each Chinese herbal medicine. In addition, the referral sources for herbal medicine consumption were documented among users. The baseline survey also collected information on sociodemographic (age, educational level, employment status, household income), health-related (parity, attendance at antenatal classes) and antenatal lifestyle (smoking status, alcohol drinking, tea drinking) characteristics. Follow-up interviews by telephone were then conducted at one, three and six months postpartum to obtain detailed information on subsequent usage pattern and lifestyle habits. To determine antenatal smoking status, participants who reported smoking any cigarette during pregnancy were classified as smokers and otherwise as non-smokers. Likewise, postnatal smokers were those who smoked any cigarette within the six months postpartum. Both alcohol drinking and tea drinking were defined in a similar manner. The content validity of questions regarding herbal medicines usage was verified through a pilot study involving 30 pregnant women from the same catchment area. Other questions used in this study had been previously validated for Chinese mothers (Qiu et al., 2010). By six months postpartum, 599 women (86.2%) remained in the cohort. Among the dropouts, 55 mothers (57.3%) could no longer be reached by telephone, 39 (40.6%) decided to withdraw, whereas two women (2.1%) declined to be interviewed because their infants were severely ill. A flowchart of participant recruitment and follow-up is presented in Fig. 1. Statistical analysis Users of Chinese herbal medicine during pregnancy were defined as women who had consumed at least one type of Chinese herbal medicines between the estimated conception date and the date of childbirth. Similarly, users in the postpartum period were mothers who had taken any Chinese herbal medicine within the first six months postpartum. Descriptive statistics were first applied to profile and compare the sample characteristics between users and non-users. The prevalence of Chinese herbal medicine consumption was next tabulated, along with the frequency and duration of usage for each type of herbal medicine among users. Ordinary logistic and logistic mixed regression models were then performed to ascertain factors associated with herbal consumption during pregnancy and the postnatal period, respectively. The latter model incorporated random subject effects to specifically account for the correlation of the repeated measures. Corresponding antenatal and postnatal lifestyle variables were included in the analyses for the two periods. All data analyses were conducted using the SPSS package version 22 (IBM, Armonk, NY, USA).
Please cite this article as: Tang, L., et al., Consumption of Chinese herbal medicines during pregnancy and postpartum: A prospective cohort study in China. Midwifery (2015), http://dx.doi.org/10.1016/j.midw.2015.11.010i
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Eligible women identified before discharge (n=723)
• Refused to participate (n=28)
Enrollment and baseline interview at discharge (in person) (n=695)
• Withdrew (n=18) • Lost (n=29)
1 month follow-up (telephone interview) (n=648)
• Withdrew (n=16) • Lost (n=12)
3 months follow-up (telephone interview) (n=620)
• Withdrew (n=5) • Lost (n=14) • Declined due to infant illness (n=2)
6 months follow-up (telephone interview) (n=599) Fig. 1. Flowchart of participant recruitment and follow-up.
Ethical considerations The study protocol was approved by the Human Research Ethics Committee of the researcher’s institution (approval number HR 169/2009) and the local health authorities. An information letter explaining the study was given and read to each eligible woman. Informed written consent was obtained before commencement of the baseline interview. All participants were assured of anonymity and confidentiality of information provided, and that they could withdraw freely from the study at any time without prejudice.
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herbal consumption appeared to be associated with employment status, household income and postnatal tea drinking. Prevalence, frequency and duration of usage A total of 43.5% and 45.0% of women reported Chinese herbal consumption during pregnancy and the first six months postpartum, respectively. Table 2 gives the prevalence of 11 categories of Chinese herbal medicines used by the participants. The most commonly consumed herbal medicine among pregnant women was Angelica sinsensis (commonly known as Dong quai) (28.8%), followed by Ziziphus jujuba (Hong zao) (21.6%) and Dioscorea opposita (Shan yao) (13.1%). In the postpartum period, Angelica sinsensis (26.8%) and Dioscorea opposita (13.9%) remained popular, but Codonopsis pilosula (Dang shen) (12.4%) has overtaken Ziziphus jujuba (8.6%). Table 3 presents the frequency and duration of intake for the three most popular herbal medicines. Although they were taken more regularly by postpartum users, the median usage duration varied from two to three months during pregnancy but 1–1.6 months postpartum. Referral sources As shown in Table 4, recommendations to consume Chinese herbal medicines were primarily made by family members and relatives, particularly maternal mothers and mothers-in-law (pregnancy 42.9%; postpartum 55.1%), while hospital staff was seldom cited as a source of advice (pregnancy 10.5%; postpartum 2.0%). More than one-third of the herbal medicine users made the decision based on their own knowledge and information. Factors associated with usage Table 5 presents the results from ordinary logistic and logistic mixed regression analyses. The apparent positive association between antenatal alcohol drinking (adjusted odds ratio (OR) 2.75, 95% confidence interval (CI) 1.01–7.53) and use of Chinese herbal medicines during pregnancy remained marginal after adjusting for the effects of other confounders. Among new mothers, those with a lower household income (adjusted OR 1.52, 95% CI 1.12 to 2.04) were more likely to consume Chinese herbal medicines within the first six months postpartum.
Findings Discussion Participant characteristics The 695 participants were aged between 18 and 44 (median 24) years. The majority of them had attended formal education up to middle school (54.7%), were employed (68.8%), and came from families with a monthly income less than 3000 yuan (53.3%). Approximately 80% of the women were delivering their first infant, and 98.4% had a gestation over 37 weeks. In terms of lifestyle habits, more than 97% of the mothers had never smoked or drank alcohol whilst pregnant, and about 90% of them continued to abstain from smoking and consuming alcoholic beverages after childbirth. Meanwhile, less than 30% of mothers drank tea during the study period. Compared to women remaining in the cohort, the dropouts (n ¼96) tended to have a lower level of education, be unemployed and have more than one child, but no significant differences were evident in maternal age or monthly household income between the two groups. Table 1 compares the characteristics of Chinese herbal medicine users and non-users during pregnancy and the postpartum period. χ2 test revealed a marginal difference in alcohol drinking between pregnant users and non-users. After childbirth, Chinese
This is the first prospective study reporting the usage patterns of Chinese herbal medicines among a cohort of pregnant and postpartum women in Sichuan Province, China. The observed prevalence of 43.5% during pregnancy was higher than two surveys conducted in Taiwan 10 years ago (24.1% in 2003; 33.6% in 2006) (Chuang et al., 2007; Chuang et al., 2009) and estimate (o20%) from a recent cross-sectional study in Hangzhou, south eastern China (Zeng et al., 2014). On the other hand, our prevalence of herbal use by pregnant women was lower than that (56%) of a survey in Hong Kong (Ong et al., 2005), whereas our 45% usage postpartum was substantially less than the corresponding 87.7% reported among Taiwanese mothers (Chuang et al., 2009). Such disparities in herbal usage prevalence are expected in view of the historical changes and different economic conditions between these areas. Hong Kong is one of the most affluent cities in Asia. With strong policy support, Chinese medicine has undergone significant development in Hong Kong since the transfer of sovereignty from the United Kingdom to China in 1997 (Chung et al., 2007). Taiwan, recording a gross domestic product of 22,598 US dollars per capita in 2014, is generally more modernised than
Please cite this article as: Tang, L., et al., Consumption of Chinese herbal medicines during pregnancy and postpartum: A prospective cohort study in China. Midwifery (2015), http://dx.doi.org/10.1016/j.midw.2015.11.010i
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Table 1 Characteristics of mothers by usage of Chinese herbal medicines during pregnancy and the first six months postpartum. Characteristic
Pregnancyn Non-user (n¼ 385)
Postpartumn (0–6 months)
Age at childbirth o30 years Z30 years
308 (80.8%) 77 (20.2%)
Educational level Middle school or below High school or above
216 (56.1%) 169 (43.9%)
157 (53.0%) 139 (47.0%)
Employment status before pregnancy Not employed Employed
114 (29.6%) 271 (70.4%)
97 (32.8%) 199 (67.2%)
Monthly household income 43000 yuan r3000 yuan
152 (43.4%) 198 (56.6%)
142 (50.9%) 137 (49.1%)
Parity Primiparous Multiparous
301 (78.2%) 84 (21.8%)
241 (81.4%) 55 (18.6%)
Attendance at prenatal classes No Yes
320 (83.1%) 65 (16.9%)
234 (79.1%) 62 (20.9%)
Smoking status Non-smoker Smoker
380 (98.7%) 5 (1.3%)
290 (98.0%) 6 (2.0%)
Alcohol drinking No Yes
378 (98.2%) 7 (1.8%)
Tea drinking No Yes
274 (71.2%) 111 (28.8%)
n
†
p†
User (n ¼296)
Non-user (n ¼360)
User (n¼ 294)
301 (83.6%) 59 (16.4%)
241 (82.0%) 53 (18.0%)
201 (55.8%) 159 (44.2%)
157 (53.4%) 137 (46.6%)
94 (26.1%) 266 (73.9%)
105 (35.7%) 189 (64.3%)
169 (51.7%) 158 (48.3%)
111 (40.1%) 166 (59.9%)
295 (81.9%) 65 (18.1%)
232 (78.9%) 62 (21.1%)
292 (81.1%) 68 (18.9%)
241 (82.0%) 53 (18.0%)
359 (99.7%) 1 (0.3%)
291 (99.0%) 3 (1.0%)
329 (91.4%) 31 (8.6%)
261 (88.8%) 33 (11.2%)
293 (81.4%) 67 (18.6%)
216 (73.5%) 78 (26.5%)
0.063 253 (85.5%) 43 (14.5%)
0.580
0.426
0.534
0.377
0.008
0.062
0.004
0.299
0.329
0.177
0.778
0.659
0.479
0.049 283 (95.6%) 13 (4.4%)
0.263
0.525 204 (68.9%) 92 (31.1%)
p†
0.015
Missing data present. From χ2 test of association.
Table 2 Prevalence of Chinese herbal medicines use during pregnancy and the first six months postpartum. Category
Angelica sinensis Ziziphus jujuba Dioscorea opposita Lycium barbarum Codonopsis pilosula Gastrodia elata Ginkgo biloba seeds Panax ginseng Astragalus membranaceus Adenophora tetraphylla Miscellaneousn Overall n
Pregnancy
Postpartum (month)
(n ¼681)
0–1 (n ¼648)
2–3 (n¼ 620)
4–6 (n ¼599)
0–6 (n¼ 654)
107 (16.5%) 36 (5.6%) 45 (6.9%) 17 (2.6%) 49 (7.6%) 14 (2.2%) 3 (0.5%) 12 (1.9%) 8 (1.2%) 18 (2.8%) 23 (3.5%) 184 (28.4%)
103 (16.6%) 25 (4.0%) 42 (6.8%) 13 (2.1%) 37 (6.0%) 5 (0.8%) 1 (0.2%) 3 (0.5%) 10 (1.6%) 5 (0.8%) 9 (1.5%) 154 (24.8%)
71 (11.9%) 19 (3.2%) 32 (5.3%) 10 (1.7%) 23 (3.8%) 4 (0.7%) 2 (0.3%) 5 (0.8%) 7 (1.2%) 2 (0.3%) 2 (0.3%) 108 (18.0%)
175 (26.8%) 56 (8.6%) 91 (13.9%) 27 (4.1%) 81 (12.4%) 19 (2.9%) 5 (0.8%) 17 (2.6%) 21 (3.2%) 20 (3.1%) 29 (4.4%) 294 (45.0%)
196 (28.8%) 147 (21.6%) 89 (13.1%) 53 (7.8%) 41 (6.0%) 37 (5.4%) 26 (3.8%) 21 (3.1%) 19 (2.8%) 15 (2.2%) 38 (5.6%) 296 (43.5%)
Includes Coix lacryma-jobi seeds, Panax notoginseng, Polygonum multiflorum and Equus asinus.
mainland China. Unlike the active promotion of Chinese medicine in mainland China since 1949, health authorities in Taiwan tend to take a more conservative approach towards traditional and alternative medicine (Yeh, 2005). Antenatal alcohol drinking appeared to be marginally associated with herbal consumption. It is possible that those pregnant women who drank alcohol might take Chinese herbal medicines in an attempt to decrease alcohol concentration in their body (Li et al., 2006). The inverse association between household income
and postpartum herbal consumption was consistent with previous findings in Hong Kong (Ong et al., 2005). Since the price of many herbs can be low (less than one US dollar per kg), mothers with low family income may find Chinese herbal medicines more affordable than Western medicines and dietary supplements. The most popular herbal medicine identified was Angelica sinsensis, also commonly used by pregnant women in Hong Kong (Ong et al., 2005). According to traditional Chinese medicine, Angelica sinsensis is beneficial for pregnant women due to its
Please cite this article as: Tang, L., et al., Consumption of Chinese herbal medicines during pregnancy and postpartum: A prospective cohort study in China. Midwifery (2015), http://dx.doi.org/10.1016/j.midw.2015.11.010i
L. Tang et al. / Midwifery ∎ (∎∎∎∎) ∎∎∎–∎∎∎ Table 3 Frequency and duration of popular Chinese herbal medicines consumed by users during pregnancy and the first six months postpartum. Category
n
%n
Use at least weekly
Median duration (IQR), months
26.5% 52.4% 33.7%
3.0 (4.0) 3.0 (3.0) 2.0 (5.0)
Postpartum (n ¼294) Angelica sinensis 175 59.5% Dioscorea opposita 91 31.0% Codonopsis pilosula 81 27.6%
74.3% 59.3% 75.3%
1.6 (2.0) 1.0 (1.0) 1.0 (2.0)
IQR, interquartile range.
Factors
Pregnancy (n ¼629)
Referral sourcesn
Pregnancy (n ¼296)
Postpartum (0–6 months) (n ¼294)
Self-decision Hospital staff Private health workers Mother/mother-in-law Other family members or relatives Friends
106 31 2 127 68 20
126 6 4 162 63 6
(35.8%) (10.5%) (0.7%) (42.9%) (23.0%) (6.8%)
Age at childbirth o 30 years Z 30 years
1.00 0.73 (0.43, 1.25)
Educational level Middle school or below High school or above
1.00 1.08 (0.77, 1.51)
Employment status before pregnancy Not employed Employed
Among users of Chinese herbal medicine.
Table 4 Sources of recommendation regarding use of Chinese herbal medicine.
n
Table 5 Factors associated with Chinese herbal medicine use during pregnancy and the first six months postpartum.
Adjusted OR (95% CI)
Pregnancy (n¼296) Angelica sinensis 196 66.2% Ziziphus jujuba 147 49.7% Dioscorea opposita 89 30.1%
n
5
(42.9%) (2.0%) (1.3%) (55.1%) (21.4%) (2.0%)
Multiple responses allowed.
efficacy of enriching the blood and activating blood circulation (Wang et al., 2012). Recent in vitro research has documented many biological activities of Angelica sinsensis extracts and constituents, which may serve as a scientific basis justifying its traditional use. However, from the perspective of evidence-based medicine, welldesigned randomised clinical trials are needed to determine the effectiveness of Angelica sinsensis (Hook, 2014). Furthermore, animal research indicated that Angelica sinsensis may present a risk for women with hormone-sensitive conditions and thus should not be consumed by pregnant and nursing mothers (National Toxicology Program, 2008). In fact, fatal hepatic and renal effects associated with Chinese herbs have been reported, usually caused by the toxic components in herbs, herb-drug interactions or adulterants during preparation of herbal medicine (Teschke et al., 2014). Another concern regarding the safety of herbal medicine is contamination by toxic substances, such as lead and pesticides. A study from Taiwan found that women who consumed traditional Chinese herbs during pregnancy and lactation had higher lead concentrations in their breastmilk (Chien et al., 2006). In accordance with previous reports (Nordeng and Havnen, 2004; Rahman et al., 2008; Holst et al., 2009), family especially the older generation such as maternal mother and mother-in-law, was the main source of referral on herbal consumption. Therefore, it is important to educate both mothers and grandmothers about the potential harm of taking Chinese herbal medicines. Although only a small proportion of herbal users ( o11%) reported that they were advised by hospital staff, this should be brought to attention. It is important that health professionals working with mothers do not recommend or prescribe herbal medicines to their clients where there is a lack of evidence supporting their use. The prospective cohort design of this study minimised recall errors on the use of Chinese herbal medicines in the postpartum period. Another strength was the recruitment of participants from seven hospitals which serve the entire catchment region and thus our sample should be representative of the target population of
p
Postpartum (n ¼ 604) Adjusted OR (95% CI)
0.247
0.505 1.00 0.85 (0.53, 1.37)
0.668
0.112 1.00 1.29 (0.94, 1.76)
0.354 1.00 0.85 (0.60, 1.20)
Monthly household income 4 3000 yuan r 3000 yuan
1.00 0.76 (0.55, 1.05)
Parity Primiparous Multiparous
1.00 1.01 (0.61, 1.68)
0.132 1.00 0.79 (0.59, 1.07)
0.093
0.006 1.00 1.52 (1.12, 2.04)
0.973
Attendance at prenatal classes No Yes
1.00 1.30 (0.87, 1.96)
Smoking status Non-smoker Smoker
1.00 2.22 (0.52, 9.45)
Alcohol drinking No Yes
1.00 2.75 (1.01, 7.53)
Tea drinking No Yes
1.00 1.12 (0.79, 1.58)
p
0.278 1.00 1.29 (0.81, 2.05)
0.206
0.719 1.00 1.07 (0.74, 1.55)
0.279
0.182 1.00 3.08 (0.59, 16.00)
0.049
0.282 1.00 0.69 (0.35, 1.36)
0.539
0.738 1.00 1.07 (0.72, 1.61)
CI, confidence interval; OR, odds ratio.
Sichuan Province. Nonetheless, detailed information on the quantity of each herbal medicine consumed was not collected due to logistical difficulties. The lack of qualitative data on the perception and belief behind Chinese herbal consumption was the main limitation. Future qualitative research with in-depth interviews is recommended to explore the reasons for the prevalent use of herbal medicines among mothers. Lastly, China is a large country with diverse cultures and different stages of economic development between areas, making it difficult to generalise our findings to the entire population of Chinese mothers.
Conclusions Maternal consumption of Chinese herbal medicines appears to be common in the Sichuan Province of China. Almost half of the women consumed herbal medicines during pregnancy or after giving birth, with Angelica sinsensis being the most popular herb. Antenatal alcohol drinking and a low family income were positively associated with maternal herbal use. However, caution should be taken due to a lack of scientific evidence justifying intake for pregnant and lactating mothers.
Please cite this article as: Tang, L., et al., Consumption of Chinese herbal medicines during pregnancy and postpartum: A prospective cohort study in China. Midwifery (2015), http://dx.doi.org/10.1016/j.midw.2015.11.010i
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Conflict of interest The authors declare that they have no conflict of interest.
Role of the funding source The sponsors included in Acknowledgements had no involvement in study design, in the collection, analysis and interpretation of data, in the writing of the report, or in the decision to submit the paper for publication.
Acknowledgements Thanks are due to the mothers who took part in this research and hospital staff who assisted with the recruitment of participants. The first author is supported by an Endeavour Australia Cheung Kong Research Fellowship and partially funded by a Theme-based Research Scheme project from the Research Grants Council of Hong Kong (Grant no: T32-102/14N).
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Hall, H.G., Griffiths, D.L., McKenna, L.G., 2011. The use of complementary and alternative medicine by pregnant women: a literature review. Midwifery 27, 817–824. Holst, L., Wright, D., Haavik, S., Nordeng, H., 2009. The use and the user of herbal remedies during pregnancy. J. Altern. Complement. Med. 15, 787–792. Holst, L., Wright, D., Haavik, S., Nordeng, H., 2011. Safety and efficacy of herbal remedies in obstetrics-review and clinical implications. Midwifery 27, 80–86. Hook, I.L., 2014. Danggui to Angelica sinensis root: are potential benefits to European women lost in translation? A review. J. Ethnopharmacol. 152, 1–13. Kennedy, D.A., Lupattelli, A., Koren, G., Nordeng, H., 2013. Herbal medicine use in pregnancy: results of a multinational study. BMC Complement. Altern. Med. 13, 55. http://dx.doi.org/10.1186/1472-6882-13-355. Li, W.Z., Lu, J., Sun, X.Y., Wang, S.L., Ni, Y.M., Zhu, W.S., 2006. Studies on the effect of extracts of several Chinese herbal medicines and other medicines on alcohol dehydrogenase activity. J. Chin. Med. Mater. 29, 816–818 (in Chinese). Liu, T.G., Xiong, S.Q., Yan, Y., Zhu, H., Yi, C., 2012. Use of chinese herb medicine in cancer patients: a survey in southwestern china. Evid. Based Complement. Alternat. Med. 2012, 769042. http://dx.doi.org/10.1155/2012/769042. Mabina, M.H., Pitsoe, S.B., Moodley, J., 1997. The effect of traditional herbal medicines on pregnancy outcome. The King Edward VIII Hospital experience. S. Afr. Med. J. 87, 1008–1010. Moussally, K., Oraichi, D., Berard, A., 2009. Herbal products use during pregnancy: prevalence and predictors. Pharmacoepidemiol. Drug Saf. 18, 454–461. National Toxicology Program, 2008. Chemical Information Review Document for Dong quai [CAS Nos. 308068-61-3 (root) and 299184-76-2 (extract)] Supporting Nomination for Toxicological Evaluation by the National Toxicology Program. Available from: 〈http://ntp.niehs.nih.gov/ntp/noms/support_docs/dong_ quai090308.pdf〉 (accessed 11 August 2015). Nordeng, H., Bayne, K., Havnen, G.C., Paulsen, B.S., 2011. Use of herbal drugs during pregnancy among 600 Norwegian women in relation to concurrent use of conventional drugs and pregnancy outcome. Complement. Ther. Clin. Pract. 17, 147–151. Nordeng, H., Havnen, G.C., 2004. Use of herbal drugs in pregnancy: a survey among 400 Norwegian women. Pharmacoepidemiol. Drug Saf. 13, 371–380. Ong, C.O., Chan, L.Y., Yung, P.B., Leung, T.N., 2005. Use of traditional Chinese herbal medicine during pregnancy: a prospective survey. Acta Obstet. Gynecol. Scand. 84, 699–700. Pinn, G., Pallett, L., 2002. Herbal medicine in pregnancy. Complement. Ther. Nurs. Midwifery 8, 77–80. Qiu, L., Binns, C.W., Zhao, Y., Lee, A.H., Xie, X., 2010. Breastfeeding practice in Zhejiang province, PR China, in the context of melamine-contaminated formula milk. J. Health Popul. Nutr. 28, 189–198. Rahman, A.A., Sulaiman, S.A., Ahmad, Z., Daud, W.N., Hamid, A.M., 2008. Prevalence and pattern of use of herbal medicines during pregnancy in tumpat district, kelantan. Malays. J. Med. Sci. 15, 40–48. Smeriglio, A., Tomaino, A., Trombetta, D., 2014. Herbal products in pregnancy: experimental studies and clinical reports. Phytother. Res. 28, 1107–1116. Teschke, R., Wolff, A., Frenzel, C., Schulze, J., 2014. Review article: Herbal hepatotoxicity – an update on traditional Chinese medicine preparations. Aliment Pharmacol. Ther. 40, 32–50. Wang, C.C., Li, L., San Lau, C.B., Leung, P.C., Fung, K.P., 2013. Pregnancy outcomes, embryonic and fetal development in maternal exposure to Chinese medicines. Birth Defects Res. C Embryo Today 99, 275–291. Wang, C.C., Li, L., Tang, L.Y., Leung, P.C., 2012. Safety evaluation of commonly used Chinese herbal medicines during pregnancy in mice. Hum. Reprod. 27, 2448–2456. Yeh, Y.W., 2005. The medical-political Development of Chinese Medicine in the Democratic Process of Taiwan. Formosan J. Med. Hum 8, 61–76 (in Chinese). Zeng, Y., Zhou, Y., Chen, P., Luo, T., Huang, M., 2014. Use of complementary and alternative medicine across the childbirth spectrum in China. Complement. Ther. Med. 22, 1047–1052.
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Consumption of Chinese herbal medicines during pregnancy and postpartum: A prospective cohort study in China Li Tang, PhD (Postdoctoral Fellow)a,b,n, Andy H. Lee, PhD (Professor)b, Colin W. Binns, PhD (Professor)b, Yer Van Hui, PhD (Professor)a,c, Kelvin K.W. Yau, PhD (Professor)a a
Department of Management Sciences, City University of Hong Kong, Kowloon, Hong Kong School of Public Health, Curtin University, Perth, WA, Australia c Hang Seng Management College, New Territories, Hong Kong b
art ic l e i nf o
a b s t r a c t
Article history: Received 18 August 2015 Received in revised form 24 October 2015 Accepted 10 November 2015
Objective: to investigate usage patterns and factors associated with maternal consumption of Chinese herbal medicines in China. Design: prospective cohort study. Information on the use of Chinese herbal medicines was collected from mothers by personal interview at hospital discharge and followed up by telephone at one, three and six months postpartum. Setting: seven hospitals in Jiangyou, Sichuan Province of China. Participants: 695 mothers who gave birth to a singleton infant. Measurements: prevalence, type, frequency and duration of herbal medicine usage. Logistic mixed regression analyses were performed to determine factors affecting the use. Findings: a total of 43.5% and 45.0% of mothers consumed Chinese herbal medicines during pregnancy and postpartum, respectively. Angelica sinsensis was the most popular herbal medicine among the participants (pregnancy 28.8%, postpartum 26.8%). Although herbal medicines were taken more regularly by postpartum users, the median usage duration varied from two to three months during pregnancy but 1–1.6 months postpartum. The majority of users (pregnancy 42.9%, postpartum 55.1%) were advised by their mother or mother-in-law to take Chinese herbal medicines. Antenatal alcohol drinking (adjusted odds ratio 2.75, 95% confidence interval 1.01–7.53) was associated with a marginally higher prevalence of herbal consumption during pregnancy, whereas mothers with a lower family income (adjusted odds ratio 1.52, 95% confidence interval 1.12–2.04) were more likely to consume Chinese herbal medicines in the postpartum period. Key conclusions and implications for practice: consumption of Chinese herbal medicines appears to be prevalent among Chinese mothers, especially those drinking alcohol whilst pregnant and women from a lower income household. Maternity health professionals need to be aware of the lack of evidence to support the use of Chinese herbal medicines during pregnancy and postpartum, and to provide their clients with scientifically based advice regarding herbal medicine use. & 2015 Elsevier Ltd. All rights reserved.
Keywords: Chinese herbal medicine Pregnancy Postpartum China
Introduction Herbal medicines are often regarded as ‘natural’ and therefore ‘safe’, although there is little scientific basis for this belief. Worldwide, studies have documented that maternal consumption of n Corresponding author at: Department of Management Sciences, G7502, Green Zone, Academic 1, Tat Chee Avenue, City University of Hong Kong, Kowloon, Hong Kong. E-mail addresses: [email protected] (L. Tang), [email protected] (A.H. Lee), [email protected] (C.W. Binns), [email protected] (Y.V. Hui), [email protected] (K.K.W. Yau).
herbal medicines is common during pregnancy and the postpartum period (Rahman et al., 2008; Chuang et al., 2009; Holst et al., 2009; Hall et al., 2011; Nordeng et al., 2011). The reported prevalence of herbal intake during pregnancy ranged from 12% to 44% in Australia (Pinn and Pallett, 2002; Forster et al., 2006; Frawley et al., 2013; Kennedy et al., 2013) and from 36% to 58% in European countries (Nordeng and Havnen, 2004; Holst et al., 2009; Nordeng et al., 2011). The herbal consumption rate among Asian women was similarly high at 51% in Malaysia and 40% in Palestine (Rahman et al., 2008; Al-Ramahi et al., 2013). Recent studies of Chinese communities suggested that 34% of Taiwanese women consumed at
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Please cite this article as: Tang, L., et al., Consumption of Chinese herbal medicines during pregnancy and postpartum: A prospective cohort study in China. Midwifery (2015), http://dx.doi.org/10.1016/j.midw.2015.11.010i
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least one type of Chinese herbal medicine during pregnancy (Chuang et al., 2009), and the corresponding rate was 56% in Hong Kong (Ong et al., 2005). With regard to herbal medicine usage after childbirth, data were scarce and the published prevalence appeared to vary widely between societies. For instance, nearly 14% of 3354 Canadian women in a survey reported herbal products consumption during their first year after childbirth (Moussally et al., 2009), much lower than the prevalence of 88% (within six months postpartum) observed in a population-based study from Taiwan (n¼21,248) (Chuang et al., 2009). Different herbal medicines are used between ethnic groups due to the diversity in cultural background and traditional beliefs (Rahman et al., 2008; Chuang et al., 2009; Nordeng et al., 2011). Their potential adverse effects on mother and fetus, such as hepatotoxic and carcinogenic effects, fetal distress, low birthweight and birth defects, have been documented extensively (Mabina et al., 1997; Ernst, 2002; Chuang et al., 2006; Wang et al., 2013). Nevertheless, very few published randomised clinical trials have evaluated the therapeutic effects of herbal products (Guo et al., 2007), and even less data are available concerning their efficacy for pregnant or lactating women (Holst et al., 2011; Smeriglio et al., 2014). Factors that influence maternal consumption of herbal medicines also vary across populations. For example, a survey in the United Kingdom revealed that women who had been pregnant before and those with a university degree tended to use herbal remedies during pregnancy (Holst et al., 2009), yet primiparous mothers in Australia were more likely to take herbal supplements during pregnancy than their multiparous counterparts (Forster et al., 2006). Moreover, while an inverse association was found between education and use of Chinese herbal medicines among Hong Kong pregnant women (Ong et al., 2005), higher educational level was linked to a higher prevalence of herbal consumption by pregnant and postnatal mothers in Taiwan (Chuang et al., 2009). Traditional Chinese medicine has been practiced in China since ancient times, with Chinese herbal medicine being the most frequently used category (Liu et al., 2012). However, a comprehensive literature search found only one published study documenting maternal use of Chinese herbal medicines in mainland China. This cross-sectional survey of 306 women, conducted in the south eastern city of Hangzhou, reported that one in five women used Chinese herbal medicines during pregnancy, childbirth or within 42 days postpartum (Zeng et al., 2014). In view of the lack of epidemiological information on herbal consumption, the present study aimed to determine the prevalence and pattern of Chinese herbal medicines usage by Chinese women during pregnancy and the first six months postpartum, and to identify the commonly consumed herbal medicines. Factors associated with Chinese herbal usage, as well as their sources of recommendation, were also investigated.
Methods Study design and setting A prospective cohort study was undertaken during 2010–2011 in Jiangyou, Sichuan Province of China. Sichuan is a large province in Western China with a population of 80 million people. According to its provincial Health and Family Planning Commission, the hospital delivery rate was approximately 95% in 2011. Jiangyou, a typical county-level town with a population of 880,000, is located 160 km north of the provincial capital city Chengdu. Between March and November 2010, mothers aged Z18 years, who gave birth to a singleton infant at one of the seven hospitals in Jiangyou, were invited to participate in this study
before discharge. Exclusion criteria were unable to answer the questions due to limited understanding or deemed unwell to participate as advised by hospital health professionals. This study planned to recruit a sample of 650 women at baseline. The sample size was calculated by assuming a prevalence of herbal consumption between 51% and 60% in the first six months postpartum (at 5% level of significance) and accounting for a 10% non-response rate and a 20% drop-out rate. Of the total 723 eligible women invited to participate, 695 consented, yielding a response rate of 96%. Questionnaire and procedure At discharge, all consented women were interviewed face-toface by the first author or one of the trained hospital staff using a structured questionnaire. Chinese herbal medicine was defined as a locally available herb (the whole or part of a plant) or herbal processed product which had been empirically known to be effective in treating disorders and maintaining good health. Information on the frequency and duration of usage was recorded for each Chinese herbal medicine. In addition, the referral sources for herbal medicine consumption were documented among users. The baseline survey also collected information on sociodemographic (age, educational level, employment status, household income), health-related (parity, attendance at antenatal classes) and antenatal lifestyle (smoking status, alcohol drinking, tea drinking) characteristics. Follow-up interviews by telephone were then conducted at one, three and six months postpartum to obtain detailed information on subsequent usage pattern and lifestyle habits. To determine antenatal smoking status, participants who reported smoking any cigarette during pregnancy were classified as smokers and otherwise as non-smokers. Likewise, postnatal smokers were those who smoked any cigarette within the six months postpartum. Both alcohol drinking and tea drinking were defined in a similar manner. The content validity of questions regarding herbal medicines usage was verified through a pilot study involving 30 pregnant women from the same catchment area. Other questions used in this study had been previously validated for Chinese mothers (Qiu et al., 2010). By six months postpartum, 599 women (86.2%) remained in the cohort. Among the dropouts, 55 mothers (57.3%) could no longer be reached by telephone, 39 (40.6%) decided to withdraw, whereas two women (2.1%) declined to be interviewed because their infants were severely ill. A flowchart of participant recruitment and follow-up is presented in Fig. 1. Statistical analysis Users of Chinese herbal medicine during pregnancy were defined as women who had consumed at least one type of Chinese herbal medicines between the estimated conception date and the date of childbirth. Similarly, users in the postpartum period were mothers who had taken any Chinese herbal medicine within the first six months postpartum. Descriptive statistics were first applied to profile and compare the sample characteristics between users and non-users. The prevalence of Chinese herbal medicine consumption was next tabulated, along with the frequency and duration of usage for each type of herbal medicine among users. Ordinary logistic and logistic mixed regression models were then performed to ascertain factors associated with herbal consumption during pregnancy and the postnatal period, respectively. The latter model incorporated random subject effects to specifically account for the correlation of the repeated measures. Corresponding antenatal and postnatal lifestyle variables were included in the analyses for the two periods. All data analyses were conducted using the SPSS package version 22 (IBM, Armonk, NY, USA).
Please cite this article as: Tang, L., et al., Consumption of Chinese herbal medicines during pregnancy and postpartum: A prospective cohort study in China. Midwifery (2015), http://dx.doi.org/10.1016/j.midw.2015.11.010i
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Eligible women identified before discharge (n=723)
• Refused to participate (n=28)
Enrollment and baseline interview at discharge (in person) (n=695)
• Withdrew (n=18) • Lost (n=29)
1 month follow-up (telephone interview) (n=648)
• Withdrew (n=16) • Lost (n=12)
3 months follow-up (telephone interview) (n=620)
• Withdrew (n=5) • Lost (n=14) • Declined due to infant illness (n=2)
6 months follow-up (telephone interview) (n=599) Fig. 1. Flowchart of participant recruitment and follow-up.
Ethical considerations The study protocol was approved by the Human Research Ethics Committee of the researcher’s institution (approval number HR 169/2009) and the local health authorities. An information letter explaining the study was given and read to each eligible woman. Informed written consent was obtained before commencement of the baseline interview. All participants were assured of anonymity and confidentiality of information provided, and that they could withdraw freely from the study at any time without prejudice.
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herbal consumption appeared to be associated with employment status, household income and postnatal tea drinking. Prevalence, frequency and duration of usage A total of 43.5% and 45.0% of women reported Chinese herbal consumption during pregnancy and the first six months postpartum, respectively. Table 2 gives the prevalence of 11 categories of Chinese herbal medicines used by the participants. The most commonly consumed herbal medicine among pregnant women was Angelica sinsensis (commonly known as Dong quai) (28.8%), followed by Ziziphus jujuba (Hong zao) (21.6%) and Dioscorea opposita (Shan yao) (13.1%). In the postpartum period, Angelica sinsensis (26.8%) and Dioscorea opposita (13.9%) remained popular, but Codonopsis pilosula (Dang shen) (12.4%) has overtaken Ziziphus jujuba (8.6%). Table 3 presents the frequency and duration of intake for the three most popular herbal medicines. Although they were taken more regularly by postpartum users, the median usage duration varied from two to three months during pregnancy but 1–1.6 months postpartum. Referral sources As shown in Table 4, recommendations to consume Chinese herbal medicines were primarily made by family members and relatives, particularly maternal mothers and mothers-in-law (pregnancy 42.9%; postpartum 55.1%), while hospital staff was seldom cited as a source of advice (pregnancy 10.5%; postpartum 2.0%). More than one-third of the herbal medicine users made the decision based on their own knowledge and information. Factors associated with usage Table 5 presents the results from ordinary logistic and logistic mixed regression analyses. The apparent positive association between antenatal alcohol drinking (adjusted odds ratio (OR) 2.75, 95% confidence interval (CI) 1.01–7.53) and use of Chinese herbal medicines during pregnancy remained marginal after adjusting for the effects of other confounders. Among new mothers, those with a lower household income (adjusted OR 1.52, 95% CI 1.12 to 2.04) were more likely to consume Chinese herbal medicines within the first six months postpartum.
Findings Discussion Participant characteristics The 695 participants were aged between 18 and 44 (median 24) years. The majority of them had attended formal education up to middle school (54.7%), were employed (68.8%), and came from families with a monthly income less than 3000 yuan (53.3%). Approximately 80% of the women were delivering their first infant, and 98.4% had a gestation over 37 weeks. In terms of lifestyle habits, more than 97% of the mothers had never smoked or drank alcohol whilst pregnant, and about 90% of them continued to abstain from smoking and consuming alcoholic beverages after childbirth. Meanwhile, less than 30% of mothers drank tea during the study period. Compared to women remaining in the cohort, the dropouts (n ¼96) tended to have a lower level of education, be unemployed and have more than one child, but no significant differences were evident in maternal age or monthly household income between the two groups. Table 1 compares the characteristics of Chinese herbal medicine users and non-users during pregnancy and the postpartum period. χ2 test revealed a marginal difference in alcohol drinking between pregnant users and non-users. After childbirth, Chinese
This is the first prospective study reporting the usage patterns of Chinese herbal medicines among a cohort of pregnant and postpartum women in Sichuan Province, China. The observed prevalence of 43.5% during pregnancy was higher than two surveys conducted in Taiwan 10 years ago (24.1% in 2003; 33.6% in 2006) (Chuang et al., 2007; Chuang et al., 2009) and estimate (o20%) from a recent cross-sectional study in Hangzhou, south eastern China (Zeng et al., 2014). On the other hand, our prevalence of herbal use by pregnant women was lower than that (56%) of a survey in Hong Kong (Ong et al., 2005), whereas our 45% usage postpartum was substantially less than the corresponding 87.7% reported among Taiwanese mothers (Chuang et al., 2009). Such disparities in herbal usage prevalence are expected in view of the historical changes and different economic conditions between these areas. Hong Kong is one of the most affluent cities in Asia. With strong policy support, Chinese medicine has undergone significant development in Hong Kong since the transfer of sovereignty from the United Kingdom to China in 1997 (Chung et al., 2007). Taiwan, recording a gross domestic product of 22,598 US dollars per capita in 2014, is generally more modernised than
Please cite this article as: Tang, L., et al., Consumption of Chinese herbal medicines during pregnancy and postpartum: A prospective cohort study in China. Midwifery (2015), http://dx.doi.org/10.1016/j.midw.2015.11.010i
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Table 1 Characteristics of mothers by usage of Chinese herbal medicines during pregnancy and the first six months postpartum. Characteristic
Pregnancyn Non-user (n¼ 385)
Postpartumn (0–6 months)
Age at childbirth o30 years Z30 years
308 (80.8%) 77 (20.2%)
Educational level Middle school or below High school or above
216 (56.1%) 169 (43.9%)
157 (53.0%) 139 (47.0%)
Employment status before pregnancy Not employed Employed
114 (29.6%) 271 (70.4%)
97 (32.8%) 199 (67.2%)
Monthly household income 43000 yuan r3000 yuan
152 (43.4%) 198 (56.6%)
142 (50.9%) 137 (49.1%)
Parity Primiparous Multiparous
301 (78.2%) 84 (21.8%)
241 (81.4%) 55 (18.6%)
Attendance at prenatal classes No Yes
320 (83.1%) 65 (16.9%)
234 (79.1%) 62 (20.9%)
Smoking status Non-smoker Smoker
380 (98.7%) 5 (1.3%)
290 (98.0%) 6 (2.0%)
Alcohol drinking No Yes
378 (98.2%) 7 (1.8%)
Tea drinking No Yes
274 (71.2%) 111 (28.8%)
n
†
p†
User (n ¼296)
Non-user (n ¼360)
User (n¼ 294)
301 (83.6%) 59 (16.4%)
241 (82.0%) 53 (18.0%)
201 (55.8%) 159 (44.2%)
157 (53.4%) 137 (46.6%)
94 (26.1%) 266 (73.9%)
105 (35.7%) 189 (64.3%)
169 (51.7%) 158 (48.3%)
111 (40.1%) 166 (59.9%)
295 (81.9%) 65 (18.1%)
232 (78.9%) 62 (21.1%)
292 (81.1%) 68 (18.9%)
241 (82.0%) 53 (18.0%)
359 (99.7%) 1 (0.3%)
291 (99.0%) 3 (1.0%)
329 (91.4%) 31 (8.6%)
261 (88.8%) 33 (11.2%)
293 (81.4%) 67 (18.6%)
216 (73.5%) 78 (26.5%)
0.063 253 (85.5%) 43 (14.5%)
0.580
0.426
0.534
0.377
0.008
0.062
0.004
0.299
0.329
0.177
0.778
0.659
0.479
0.049 283 (95.6%) 13 (4.4%)
0.263
0.525 204 (68.9%) 92 (31.1%)
p†
0.015
Missing data present. From χ2 test of association.
Table 2 Prevalence of Chinese herbal medicines use during pregnancy and the first six months postpartum. Category
Angelica sinensis Ziziphus jujuba Dioscorea opposita Lycium barbarum Codonopsis pilosula Gastrodia elata Ginkgo biloba seeds Panax ginseng Astragalus membranaceus Adenophora tetraphylla Miscellaneousn Overall n
Pregnancy
Postpartum (month)
(n ¼681)
0–1 (n ¼648)
2–3 (n¼ 620)
4–6 (n ¼599)
0–6 (n¼ 654)
107 (16.5%) 36 (5.6%) 45 (6.9%) 17 (2.6%) 49 (7.6%) 14 (2.2%) 3 (0.5%) 12 (1.9%) 8 (1.2%) 18 (2.8%) 23 (3.5%) 184 (28.4%)
103 (16.6%) 25 (4.0%) 42 (6.8%) 13 (2.1%) 37 (6.0%) 5 (0.8%) 1 (0.2%) 3 (0.5%) 10 (1.6%) 5 (0.8%) 9 (1.5%) 154 (24.8%)
71 (11.9%) 19 (3.2%) 32 (5.3%) 10 (1.7%) 23 (3.8%) 4 (0.7%) 2 (0.3%) 5 (0.8%) 7 (1.2%) 2 (0.3%) 2 (0.3%) 108 (18.0%)
175 (26.8%) 56 (8.6%) 91 (13.9%) 27 (4.1%) 81 (12.4%) 19 (2.9%) 5 (0.8%) 17 (2.6%) 21 (3.2%) 20 (3.1%) 29 (4.4%) 294 (45.0%)
196 (28.8%) 147 (21.6%) 89 (13.1%) 53 (7.8%) 41 (6.0%) 37 (5.4%) 26 (3.8%) 21 (3.1%) 19 (2.8%) 15 (2.2%) 38 (5.6%) 296 (43.5%)
Includes Coix lacryma-jobi seeds, Panax notoginseng, Polygonum multiflorum and Equus asinus.
mainland China. Unlike the active promotion of Chinese medicine in mainland China since 1949, health authorities in Taiwan tend to take a more conservative approach towards traditional and alternative medicine (Yeh, 2005). Antenatal alcohol drinking appeared to be marginally associated with herbal consumption. It is possible that those pregnant women who drank alcohol might take Chinese herbal medicines in an attempt to decrease alcohol concentration in their body (Li et al., 2006). The inverse association between household income
and postpartum herbal consumption was consistent with previous findings in Hong Kong (Ong et al., 2005). Since the price of many herbs can be low (less than one US dollar per kg), mothers with low family income may find Chinese herbal medicines more affordable than Western medicines and dietary supplements. The most popular herbal medicine identified was Angelica sinsensis, also commonly used by pregnant women in Hong Kong (Ong et al., 2005). According to traditional Chinese medicine, Angelica sinsensis is beneficial for pregnant women due to its
Please cite this article as: Tang, L., et al., Consumption of Chinese herbal medicines during pregnancy and postpartum: A prospective cohort study in China. Midwifery (2015), http://dx.doi.org/10.1016/j.midw.2015.11.010i
L. Tang et al. / Midwifery ∎ (∎∎∎∎) ∎∎∎–∎∎∎ Table 3 Frequency and duration of popular Chinese herbal medicines consumed by users during pregnancy and the first six months postpartum. Category
n
%n
Use at least weekly
Median duration (IQR), months
26.5% 52.4% 33.7%
3.0 (4.0) 3.0 (3.0) 2.0 (5.0)
Postpartum (n ¼294) Angelica sinensis 175 59.5% Dioscorea opposita 91 31.0% Codonopsis pilosula 81 27.6%
74.3% 59.3% 75.3%
1.6 (2.0) 1.0 (1.0) 1.0 (2.0)
IQR, interquartile range.
Factors
Pregnancy (n ¼629)
Referral sourcesn
Pregnancy (n ¼296)
Postpartum (0–6 months) (n ¼294)
Self-decision Hospital staff Private health workers Mother/mother-in-law Other family members or relatives Friends
106 31 2 127 68 20
126 6 4 162 63 6
(35.8%) (10.5%) (0.7%) (42.9%) (23.0%) (6.8%)
Age at childbirth o 30 years Z 30 years
1.00 0.73 (0.43, 1.25)
Educational level Middle school or below High school or above
1.00 1.08 (0.77, 1.51)
Employment status before pregnancy Not employed Employed
Among users of Chinese herbal medicine.
Table 4 Sources of recommendation regarding use of Chinese herbal medicine.
n
Table 5 Factors associated with Chinese herbal medicine use during pregnancy and the first six months postpartum.
Adjusted OR (95% CI)
Pregnancy (n¼296) Angelica sinensis 196 66.2% Ziziphus jujuba 147 49.7% Dioscorea opposita 89 30.1%
n
5
(42.9%) (2.0%) (1.3%) (55.1%) (21.4%) (2.0%)
Multiple responses allowed.
efficacy of enriching the blood and activating blood circulation (Wang et al., 2012). Recent in vitro research has documented many biological activities of Angelica sinsensis extracts and constituents, which may serve as a scientific basis justifying its traditional use. However, from the perspective of evidence-based medicine, welldesigned randomised clinical trials are needed to determine the effectiveness of Angelica sinsensis (Hook, 2014). Furthermore, animal research indicated that Angelica sinsensis may present a risk for women with hormone-sensitive conditions and thus should not be consumed by pregnant and nursing mothers (National Toxicology Program, 2008). In fact, fatal hepatic and renal effects associated with Chinese herbs have been reported, usually caused by the toxic components in herbs, herb-drug interactions or adulterants during preparation of herbal medicine (Teschke et al., 2014). Another concern regarding the safety of herbal medicine is contamination by toxic substances, such as lead and pesticides. A study from Taiwan found that women who consumed traditional Chinese herbs during pregnancy and lactation had higher lead concentrations in their breastmilk (Chien et al., 2006). In accordance with previous reports (Nordeng and Havnen, 2004; Rahman et al., 2008; Holst et al., 2009), family especially the older generation such as maternal mother and mother-in-law, was the main source of referral on herbal consumption. Therefore, it is important to educate both mothers and grandmothers about the potential harm of taking Chinese herbal medicines. Although only a small proportion of herbal users ( o11%) reported that they were advised by hospital staff, this should be brought to attention. It is important that health professionals working with mothers do not recommend or prescribe herbal medicines to their clients where there is a lack of evidence supporting their use. The prospective cohort design of this study minimised recall errors on the use of Chinese herbal medicines in the postpartum period. Another strength was the recruitment of participants from seven hospitals which serve the entire catchment region and thus our sample should be representative of the target population of
p
Postpartum (n ¼ 604) Adjusted OR (95% CI)
0.247
0.505 1.00 0.85 (0.53, 1.37)
0.668
0.112 1.00 1.29 (0.94, 1.76)
0.354 1.00 0.85 (0.60, 1.20)
Monthly household income 4 3000 yuan r 3000 yuan
1.00 0.76 (0.55, 1.05)
Parity Primiparous Multiparous
1.00 1.01 (0.61, 1.68)
0.132 1.00 0.79 (0.59, 1.07)
0.093
0.006 1.00 1.52 (1.12, 2.04)
0.973
Attendance at prenatal classes No Yes
1.00 1.30 (0.87, 1.96)
Smoking status Non-smoker Smoker
1.00 2.22 (0.52, 9.45)
Alcohol drinking No Yes
1.00 2.75 (1.01, 7.53)
Tea drinking No Yes
1.00 1.12 (0.79, 1.58)
p
0.278 1.00 1.29 (0.81, 2.05)
0.206
0.719 1.00 1.07 (0.74, 1.55)
0.279
0.182 1.00 3.08 (0.59, 16.00)
0.049
0.282 1.00 0.69 (0.35, 1.36)
0.539
0.738 1.00 1.07 (0.72, 1.61)
CI, confidence interval; OR, odds ratio.
Sichuan Province. Nonetheless, detailed information on the quantity of each herbal medicine consumed was not collected due to logistical difficulties. The lack of qualitative data on the perception and belief behind Chinese herbal consumption was the main limitation. Future qualitative research with in-depth interviews is recommended to explore the reasons for the prevalent use of herbal medicines among mothers. Lastly, China is a large country with diverse cultures and different stages of economic development between areas, making it difficult to generalise our findings to the entire population of Chinese mothers.
Conclusions Maternal consumption of Chinese herbal medicines appears to be common in the Sichuan Province of China. Almost half of the women consumed herbal medicines during pregnancy or after giving birth, with Angelica sinsensis being the most popular herb. Antenatal alcohol drinking and a low family income were positively associated with maternal herbal use. However, caution should be taken due to a lack of scientific evidence justifying intake for pregnant and lactating mothers.
Please cite this article as: Tang, L., et al., Consumption of Chinese herbal medicines during pregnancy and postpartum: A prospective cohort study in China. Midwifery (2015), http://dx.doi.org/10.1016/j.midw.2015.11.010i
L. Tang et al. / Midwifery ∎ (∎∎∎∎) ∎∎∎–∎∎∎
6
Conflict of interest The authors declare that they have no conflict of interest.
Role of the funding source The sponsors included in Acknowledgements had no involvement in study design, in the collection, analysis and interpretation of data, in the writing of the report, or in the decision to submit the paper for publication.
Acknowledgements Thanks are due to the mothers who took part in this research and hospital staff who assisted with the recruitment of participants. The first author is supported by an Endeavour Australia Cheung Kong Research Fellowship and partially funded by a Theme-based Research Scheme project from the Research Grants Council of Hong Kong (Grant no: T32-102/14N).
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Please cite this article as: Tang, L., et al., Consumption of Chinese herbal medicines during pregnancy and postpartum: A prospective cohort study in China. Midwifery (2015), http://dx.doi.org/10.1016/j.midw.2015.11.010i