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Employment and Health-Risk Behaviors Among Pregnant Adolescents
J Pediatr Adolesc Gynecol (1998) 11:79-84
Employment and Health-Risk Behaviors Among Pregnant Adolescents V. 1. Ricke此， PsyD , C.M. Wiemann , PhD , L.A. Goodrum , MD , and A.B. Berenson, MD Divisions of Pediatric and Adolescent Gynecology and Maternal-Fetal Medicine , Department of Obstetrics and Gynecology , The University of Texas Medical Branch at Galveston , Galveston , Texas
Abstract. Study Objective: To compare health-risk behaviors , maternal , and neonatal outcomes of pregnant adolescents less than 18 years old who reported employment more than 15 hours per week with those who did not report working. We hypothesized that working teens compared with nonworking adolescents would report higher rates of health-risk behaviors. Methods: A structured interview was conducted at the first prenatal visit and the medical chart was reviewed to extract pregnancy (pregnancy-induced hypertension , preterm labor with hospitalization , and preterm delivery) and neonatal outcomes (low birthweight , small for gestational age, and admission to the neonatal intensive care unit). The study was conducted at an outpatient maternal and child health clinic at a 111), university teaching hospital. A total of 384 white (n African An1erican (n = 151), and Mexican American (n = 99) adolescents , aged 12 to 17 years , who initiated care between January 2, 1992, and December 31, 1994, and delivered an infant at our institution were consecutively sampled. A structured interview assessed various health-risk behaviors including age at first intercourse , substance use (tobacco , alcohol, and other illicit drug use) , and nlunber of sexual partners. Medical records were reviewed to obtain information on pregnancy complications (pregnancy-induced hypertension , preterm delivery , and preterm labor with hospitalization) and negative birth outcomes (infant birthweight and neonatal intensive care admission). Results: Controlling for chronological age, logistic regression analyses found that adolescents reporting employment at their first prenatal visit (n = 40) compared with those not employed at this visit (n = 331) were more likely to be characterized by school enrollment , higher econon1icstatus, partner employment , partner alcohol use , and a longer relationship with the father of their baby. Multivariate logistic regression found that employed females were 4.6 times more likely to deliver a small-for-gestational-age infan t.
Presented in p 訂t at the 10th annual meeting of the North American Society for Pediatric and Adolescent Gynecology , SanDiego , California, May 17, 1996. Address reprint requests to: V. J. Ricke此， PsyD , Division of Pediatric and Adolescent Gynecology , 301 University Boulevard, Galveston , Texas 77555-0587. 1083-3188 © 1998 Lippincott-Raven Publishers
Conclusions: Employment reported at the time of the first prenatal visit does not appear to be associated with an increase in health-risk behaviors or obstetric complications , but a relationship between working more than 15 hours and small-forgestational-age delivery was detected.
Key Words. Pregnancy一-Adolescent-Employment Health-risk behaviors-Obstetric complicationsNeonatal outconles
Introduction Employment is a significant and often essential factor in the lives of many adolescents. 1- 5 Nationally collected data suggest that roughly two thirds of high school seniors and half of high school sophomores hold part-time jobs while going to school? Benefits of part-time employment include money for personal or family use , enhanced feelings of competence and independence , and family approval. 1 Unfortunately , the advantages of employment for adolescents who work more than a few hours per week may be outweighed by certain increases in health-risk behaviors. Several studies suggest that those adolescents who work in excess of 15 hours per week are at greater risk for substance use , dropping out of school , and delinquency.3-8 For example , among a large sample of 15- to 18-year-olds , an increase in work hours was associated with poorer school performance , increased use of alcohol , decreased family contacts , and cynical attitudes toward work. 3 Despite increasing numbers of adolescent females entering the workforce ,9 , 10 research examining the health effects of employment on young women has been minimal. It has been reported that stressful work is related to alcohol and marijuana use for both male and female adolescents , but only among girls is it related to increased
80
Rickert et al: Employment and Adolescent Pregnancy
rates of school absenteeism. 4 Moreover, Whitehead and Layne 11 found higher rates of heavy drinking among employed female adolescents aged 15 to 19 years than among same-aged employed male adolescents (29% v 17%). These data have important implications for employed female adolescents who become pregnant because many young gravidas face higher obstetric risks caused by adverse nutritional , socioeconomic , and behavioral factors. 12- 14 Thus , the association between employment and health-risk behaviors during some or all of the adolescent' s pregnancy requires evaluation and has not been examined within this population. As a first step in filling this void , we compared healthrisk behaviors of pregnant adolescents who reported employment more than 15 hours per week with those young gravidas who did not report working at their first prenatal visi t. We hypothesized that working teens would report significantly higher rates of substance use and other health-risk behaviors. In addition , we examined rates of pregnancy complications and negative birth outcon1es between these two groups , as past research among adult employed women has demonstrated increased rates of premature delivery , 15 , 16 low birthweight, 17 and spontaneous abortion. 18
Materials and Methods Those eligible to participate in the present investigation were adolescents less than 18 years of age who initiated prenatal care at The University of Texas Medical Branch at Galveston Adolescent Obstetrics Clinic between January 2, 1992, and December 31 , 1994; completed a structured interview at the time of their first prenatal visit (mean , 15.5 weeks; SD , 7.8 weeks); and delivered an infant at our institution (n 384). These facilities primarily serve a tri-ethnic adolescent population (white , Mexican American , and African American) whose families live at or below the poverty leve l. As part of standard care , adolescents were asked at their first prenatal visit to complete a structured interview by one of two trained female clinic assistants. The structured interview was adapted from measures previously published in the adolescent literature and piloted with a small number of adolescents. Information on age , race , school enrollment , number of hours worked per week , and household composition was elicited. Standardized questions on health-risk behaviors included age at first intercourse , substance use (tobacco , alcohol , and other illicit drugs) during the last 12 months and since their last menstrual period , as well as lifetime number of sexual partners. In addition , each subject was asked to provide information about the father of her baby , including his employment status , the length of their relationship , and the weekly frequency of his alcohol and other drug use. Although subjects were consecutively inter-
viewed , 8% of females who received care were not interviewed because of scheduling difficulties. With institutional review board approval , a trained research assistant extracted the following data from subjec t' s medical record: financial status; reproductive history; results of urine drug screens (cannabinoids , cocaine , and opiates) conducted at the first prenatal visit; examination results for sexually transmitted disease and sonography; fetal birth weight; gestational age at delivery; occurrence of pregnancy-induced hypertension , neonatal intensive care admission , preterm delivery , preterm labor with hospitalization , and whether the infant was small for gestational age from the subjec t' s and her infan t' s medical records. Data Definitions Subjects were considered employed at the time of their first prenatal visit if they reported working outside the home more than 15 hours per week. Thirteen subjects who reported employment but worked 15 hours per week or less were excluded from subsequent analyses. Living with a parent and use of tobacco , alcohol , or marijuana during the last 12 months and use since the last menstrual period were all coded as "yes" or '‘ no." Tobacco and alcohol use was based on self-report; however, marijuana and other illicit drug use was based on both self-report and urine drug screens that were conducted on 95% of subjects sampled. Thus , drug use was confirmed if either the subjec t' s urine drug screen was positive or she selfreported use. Number of lifetime sexual partners was categorized as 石2 or >3. Based on reports by the pregnant adolescent, partner employment was coded as either "yes" or "no ," whereas weekly use of alcohol and other illicit drugs was coded as none , 1-2, and>2 times per week. Finally , length of relationship with this male partner was treated as a continuous variable and was measured in months. Using routinely collected financial information , economic status was defined as either 0%-100% or >100 0/0 of the federally established poverty level based on the adolescent' s self-report of the family' s household income and the number of household members dependent on that income. Reproductive information obtained from the medical record was dichotomized and included parity (0 or ~ 1), gravidity (逗 1 or >1), and number of past abortions (0 or ~ 1). Participants were screened for sexually transmitted disease (gonorrhea, chlamyd間， syphilis , and condylomatous lesions). Maternal complications examined included pregnancy-induced hypertension , preterm labor with at least one day of hospitalization , and cesarean section and were coded as present if the subject's medical record confirmed these complications. Small-for-gestational age was defined as a birthweight that was below the 10th percentile for gestational age according to the Brenner scale. 19 Consistent with the clinical literature , those infants who weighed less than
Rickert et al: Employment and Adolescent Pregnancy 2500 g were considered low birthweight. Finally , admission to the neonatal intensive care unit was coded as “ yes" or "no." Premature birth was coded "present" if the gestational age at delivery was less than 37 weeks. Fewer than 8% of the subjects had missing data for any outcome evaluated.
81
many covariates included in the model as the sample size would permit, and the contribution of individual covariates to the model was exan1ined as each was added to or removed from these analyses.
Results Statistical Analysis Analyses were first conducted to examine the effects of employment on health-risk behaviors , and , second, to examine the effects of employment on maternal and neonatal outcomes. Demographic , reproductive , and healthrisk behaviors were compared among patients stratified by employment (employed >15 hours per week versus not employed) using X2 or Student' s t-tests , depending on the level of measuremen t. Bivariate correlates (石 0 . 1 0) were then considered for entry into stepwise logistic regression analyses to identify health-risk behaviors independently associated with employment. Next，χ2 analyses were used to compare the prevalence of maternal and neonatal outcomes between employed and nonemployed adolescents. The relative risk of complications among employed versus nonemployed adolescents was estimated by calculating odds ratio and 95% confidence limits (95% CL). Stratified analyses were performed to identify data-specific confounders. We then conducted logistic analyses to a句ust the relative risk of each maternal and neonatal outcome among employed and nonemployed adolescents. Variables known to be related to outcomes , such as estimated gestational age at entry into prenatal care , smoking prepregnant weight , weight gain during pregnancy , parity , height , 11 and other confounders identified from these stratified analyses were used in these analyses to control for these effects. Unfortunately , it was not possible to simultaneously enter all covariates into multivariate analyses for each outcome because of the small sample size. Thus , logistic regression analyses were conducted , with as
A total of 40 adolescents reported working more than 15 331) reported not hours per week , whereas 86% (n working at the time of their first prenatal visi t. Twentythree (58%) of the employed adolescents worked 16 to 20 hours , 10 (25%) worked 21 to 28 hours , and the remaining 7 (17%) worked 30 or more hours. Most working adolescents in our sample were employed in the food service industry (fast-food , waitress , or hostess) or retail stores (cashiers or salespersons). Employed compared with nonemployed female adolescents were older (16.6ν15.8 years~ p < 0.01) , reported a higher economic status (30%ν16%~ p < 0.01) , were more likely to report that their partner was also employed (74% v 49%~ p < 0.01) , and a longer ongoing relationship with their baby's father (20 v 14 months~ p < 0.01). As can be seen in Table 1, reproductive characteristics , race/ ethnicity , and living arrangements did not differentiate employed from nonemployed gravidas. Differences in health-risk behaviors were detected among employed and nonemployed teenagers (Table 2). Subjects who worked more than 15 hours per week were more likely to report school enrollment and to have experienced first intercourse after the age of 14 years~ however, no differences in the number of lifetime sexual partners were found between these groups. Although en1ployed females had fewer confirmed sexually transmitted diseases during pregnancy (14% v 23%) , this finding was nonsignificant. Substance use including use of tobacco , alcohol , and marijuana since their last menstrual period did not differ between these groups of subjects.
Table 1. Selected Demographic Characteristics of Employed Versus Not Employed Adolescents
No.
%
No.
%
Gravidity (>1) Parity (~1) Abortion (注 1 ) Ethnicity White African American Mexican American Other Economic status (>100% of poverty level) Living with parent Current relationship with baby' s father Partner employed
8 4 4
20 10 10
85 39 20
26 12 4
15 16 8
38 40 22 2 30 71 90 74
96 135 91 9 41 210 257 148
29 41 27 3 16 64 78 49
Abbreviation: NS, not significan t.
12 30 36 26
d-sss u-
NS
0.01
NS 0.07 0.01
戶L V -
Demographic Characteristic
P 一
NotEmployed (n = 331) 訊 -N N N
Employed (n = 40)
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Rickert et al:
Employment and Adolescent Pregnancy
Table 2. Selected Risk Behaviors of Employed Versus Not Employed Pregnant Adolescents Employed (n = 40)
Not Employed (n = 331)
Demographic Characteristic
No.
%
No.
%
p Value
Enrolled in school Age at first intercourse (>14) No. of lifetime p訂tners (>1) Discussed birth control with partner Current pregnancy not planned Substance use during last 12 months Tobacco Alcohol Marijuana Substance use since last menstrual period Tobacco Alcohol Marijuana Partner alcohol use (weekly) None 1-2 times >2 times Partner drug use (weekly) None 1-2 times >2 times
33 26 30 29 36
82 65 75 74 95
231 132 212 183 270
69 40 64 57 85
0.09 0.01 NS 0.03 0.10
10 21 5
26 62 13
72 127 41
24 46 13
NS 0.07 NS
5 7 11
13 19 29
39 58 68
13 19 22
NS NS NS 0.10
10 17 9
28 47 25
141 111 53
46 36 17
26 7 5
70 18 12
259 26 22
84 9 7
0.04
Abbreviation: NS , not significan t.
Finally , weekly frequencies of alcohol (p - 0.10) and illicit drug use (p == 0.04) were higher among partners of employed conlpared with partners of nonemployed fenlale adolescents. Stepwise logistic regression analyses revealed that when controlling for age , five variables were significantly associated with being employed more than 15 hours (Table 3). Adolescents who were employed were more likely to be enrolled in school , have a partner who was enlployed , report a higher economic status , report more frequent alcohol use by their male partner , and have a longer relationship (measured in months). Thus , for every 6-month increase in the female's relationship with her partner , we found a 24% increase in the likelihood she was employed more than 15 hours per week. Multivariate analyses controlling for the effects of gestational age at entry into care and other confounders Table 3. Logistic Regression Model of Factors Associated With Employment Variable
Adjusted Odds Ratio
95% CL
School enrollment Economic status (> 100% of poverty leve l) Frequency of alcohol use by P訂tner Partner employed Length of relationship (mo)
3.57 3.24
1.32 , 9.61 1.20 , 8.76
2.04
1.16 , 3.59
3.31 1.04
1.29 , 8.5 1 1.01, 1.08
Total sample is comprised of 293 because of missing data across variabIes by some subjects. Abbreviation: CL , confidence lin1its.
found only one significant difference in maternal and neonatal complications between employed versus nonemployed young patients. Employed adolescents were 4.6 times more likely (CL: 1.1, 19.3) to deliver a smallfor-gestational-age infant compared with nonemployed gravidas when controlling for estimated gestational age at entry into prenatal care , height , race , parity , history of preterm labor , alcohol and illicit drug use , smoking , and low birthweight (p < 0.03). No differences were found between these two groups for rates of pregnancy-induced hypertension , preterm labor , cesarean section , low birthweight , or preternl delivery.
Discussion Contrary to our expectations and to trends in the research literature , these young gravidas , compared with their nonemployed peers , did not have increased rates of health-conlpromising behaviors , such as tobacco , alcohol and other drug use or high-risk sexual behaviors. In fact , employment reported at the first prenatal visit was strongly related to school involvement, as working adolescents were 3.5 times more likely to be enrolled in schoo l. Perhaps these working female adolescents represent a more mature , goal-directed group of adolescents than their younger , unemployed counte中arts. As such , they may perceive greater benefit from staying in school and may be somewhat immune to the detrimental effects on school performance that nonpregnant samples of working adolescents have reported 3 人 7，8 ; however , future
Rickert et al: Employment and Adolescent Pregnancy research with pregnant working adolescents must examine changes in school status throughout the pregnancy to test the relationships observed in our study. We did not find increased rates of harmful or illicit substance use since last menstrual period or within the past 12 months among employed compared with nonemployed pregnant female adolescents~ however , we found a trend for higher rates of alcohol use within the past 12 months and that the male partners of employed females used both alcohol and other illicit drugs n10re frequently than the male partners of nonemployed females. Thus , despite easy availability and the monetary resources to purchase these substances , our subjects may have understood the dangers associated with substance use during pregnancy. These findings are consistent with previous reports documenting decreased rates of alcohol use during adolescent pregnancy?O,2 1 Another important finding in our study was that employed teens reported a higher economic status. Specifically , employed adolescents were much more likely to report living above the poverty leve l. Because economic status was determined from the adolescent' s self-report of family income , these results must be interpreted with caution. Nevertheless , many of these young gravidas still lived with a parent and had a male partner who was also employed. In addition , employed adolescents , on average , reported a longer relationship with their male partner (20 v 14 months). The length and perhaps stability of this relationship likely contributed to increased psychological support during their pregnancy. Thus , the families' financial and psychological resources may have provided a distinct advantage for these young gravidas , 的 pri or research among pregnant adolescents suggests that those with these support mechanisms have fewer pregnancy complications. 22 ,23 As a result , these economic and psychological advantages may have contributed to the healthy maternal and neonatal outcomes observed in this study. Although we inquired about employment and the number of hours worked only at the first prenatal visit , our association between employment early in the pregnancy and delivery of a small-for-gestational-age infant is of interest but must be interpreted with caution. Henriksen et al 24 found that employn1ent during specific periods of gestation has differential effects on th
83
example , most reported working as fast -food clerks or cashiers , which frequently involve standing for prolonged periods. Alternatively , erratic eating habits or stress of both working and attending school may have played a significant role in this perinatal outcome~ however, these reasons are speculative , and further research is required as we do not know how long into their pregnancy our females maintained their employment nor the type and amount of physical labor required. Limitations of the present study should be acknowledged. First, all adolescents in our sample obtained prenatal care at some point during their pregnancy. Healthrisk behaviors as well as maternal and neonatal outcomes may be quite different an10ng those employed pregnant adolescents who do not seek medical care during pregnancy. Second , most research in this area , including ours , relies on cross-sectional data and , as such , provides a limited picture of the health-risk behavior-employment relationship.6 Future research must n10re carefully examine this relationship using longitudinal designs to better establish the effects of both pregnancy and gender among working adolescents. Clinically , these preliminary data suggest that pregnant adolescents who work more than 15 hours at the time of their first prenatal visit are not more likely to engage in health-risk behaviors than adolescents who do not report working. Health care providers should obtain a detailed history relative to both the physical and psychological aspects of employment to carefully evaluate the risk of maternal and neonatal complications. Employed pregnant adolescents , particularly those who are enrolled in school , may represent a unique group of young won1en who are motivated to better their life situation and that of their unborn child. While their determination to work should be supported , their hectic schedules and erratic , eating habits may affect their developing fetuses. Thus , the fetal growth parameters of these young women may require close attention because of the demands placed on them by school and employment in conjunction with other nutritional , socioeconomic , and medical factors that may cause fetal growth restriction.
Acknowledgments. For editorial and graphic assistance, we
thank R.G. McConnelland the Obstetricsand Gynecology Publications staff, Kristi Barrett, John Helms, and Steve Schuenke.
References 1. Fine GA, MortimerJT, Roberts DF: Leisure, work, and the
mass media. In: At the Threshold: The Developing Adolescent. Edited by SS Feldman, GR Elliott. Carrlbridge , MA, Harvard University Press, 1990 , p 225 2. Crockett LJ , Petersen AC: Adolescent development: Health risk and opportunities for health promotion. In: Pro-
84
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15. 16.
Rickert et al:
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moting the Health of Adolescents. Edited by SG Millstein , AC Petersen , EO Nightingale. New York , Oxford University Press , 1993, p. 13 Steinberg L , Dornbusch SM: Negative correlates of parttime employment during adolescence: replication and elaboration. Dev Psychol 1991; 27:304 Kablaoui BN , Pautler AJ: The effects of part-time work experience on high school students. J Career Dev 1991; 17:195 Greenberger E , Steinberg L: When Teenagers Work: The Psychological and Social Costs of Adolescent Employment. New York , Basic Books , 1986 Roman PM , Johnson JA: Alcoho l's role in work-force entry and retiremen t. Alcohol Health Res World 1996; 20: 162 Steinberg L , Greenberger E , Garduque L , et al: High school students in the labor force: some costs and benefits to schooling and learning. Educational Evaluation and Policy Analysis 1982; 4:363 Steinberg L , Greenberger E, Garduque L, et al: Effects of working on adolescent developmen t. Dev Psychol 1982; 18:385 U.S. Department of Labor. In: Handbook of Labor Statistics. Bureau of Labor Statistics , Bulletin 2340. Washington , DC, US Government Printing Office , 1989, P 257 Barling J , Rogers KA , Kelloway ER: Some effects of teenagers' part-time employmen t: the quantity and quality of work make the difference. Journal of Organization Behavior 1995; 16:143 Whitehead PC , Layne N: Young female Canadian drinkers: employment , marital status , and heavy drinking. British Journal of Addiction 1987; 82:169 US Congress , Office of Technology Assessmen t: Adolescent Health-Volume 2: Background and the Effectiveness of Selected Prevention and Treatment Services , OTA-H466. Washington , DC , US Government Printing Office , November 1991, pp 62-64 , 526 Stevens-Simon C , McAnarney ER: Adolescent pregnancy. In: Handbook of Adolescent Health Risk Behavior. Edited by RJ DiClemente , WB Hansen , LE Ponton. New York , Plenum Press , 1996, p 313 Seitz V , Apfel NH: Effects of school for pregnant students on the incidence of low-birthweight deliveries. Child Dev 1994; 65:666 Colie CF: Preterm labor and delivery in working women. Semin Perinatol 1993; 17:37 McDonald AD , McDonald JC , Armstrong B, et al: Prema-
turity and work in pregnancy. Br J Industr Med 1988; 45: 56 17. Naeye RL , Peters EC: Working during pregnancy: effects on the fetus. Pediatrics 1992; 69:724 18. McDonald AD ， 孔1cDonald JC , Armstrong B , et al: Fetal death and work in pregnancy. Br J Industr Med 1988; 45: 148 19. Brenner WE , Edelnlan DA , Hendricks CH: A standard of fetal growth for the United States of America. Am J Obstet Gynecol 1976; 126:555 20. Zuckerman BS , Alpert 刃， Dooling E , et al: Neonatal outcome: is adolescent pregnancy a risk factor? Pediatrics 1983; 71:489 2 1. Gilchrist LD , Gillmore MR , Lohr MJ: Drug use among pregnant adolescents. In: Adolescent Substance Abuse: Etiology , Treatment , and Prevention. Edited by GW Lawson, AW Lawson. Gaithersburg , MD , Aspen Publication , 1992, P 351 22. Giblin PT , Poland ML , Sachs BA: Effects of social supports on attitudes and health behaviors of pregnant adolescents. J Adolesc Health 1987; 8:273 23. Pazarine S: Stressors , coping , and social supports of adolescent mothers. J Adolesc Health 1986; 7:153 24. Henriksen TB , Savitz DA , Hedegaard M , et al: Employment during pregnancy in relationship to risk factors and pregnancy outcome. Br J Obstet Gynaecol 1994; 101:858 25. Moss N, Carver K: Pregnant women at work: Sociodemographic perspectives. Am J Ind Med 1993; 23:541 26. Henriksen TB , Hedegaard M, Secher NJ: Standing and walking at work and birthweigh t. Acta Obstet Scand 1995; 74:509 27. Seneviratne SR, Fernado DN: Influence of work on pregnancy outcome. Int J Gynecol Obstet 1994; 45:35 28. Chamberlain GV: Work in pregnancy. Am J Ind Med 1993; 23:559 29. Klebanoff MA , Shioro PH , Carey JC: The effect of physical activity during pregnancy on preterm delivery and birthweigh t. Am J Obstet Gynecol 1990; 163:1450 30. Clapp III JF: Pregnancy outcome: physical activities inside versus outside the workplace. Semin Perinatol 1996; 20:70 3 1. Teitelman AM , Welch LS, Hellenbrand KG , et al: Effect of maternal work activity on preterm birth. Am J Epidemiol 1990; 131:104 32. Mamelle N, Laumon B, Laumon B , Lazar P: Prematurity and occupational activity during pregnancy. Am J Epidemiol 1984; 119:309
Employment and Health-Risk Behaviors Among Pregnant Adolescents V. 1. Ricke此， PsyD , C.M. Wiemann , PhD , L.A. Goodrum , MD , and A.B. Berenson, MD Divisions of Pediatric and Adolescent Gynecology and Maternal-Fetal Medicine , Department of Obstetrics and Gynecology , The University of Texas Medical Branch at Galveston , Galveston , Texas
Abstract. Study Objective: To compare health-risk behaviors , maternal , and neonatal outcomes of pregnant adolescents less than 18 years old who reported employment more than 15 hours per week with those who did not report working. We hypothesized that working teens compared with nonworking adolescents would report higher rates of health-risk behaviors. Methods: A structured interview was conducted at the first prenatal visit and the medical chart was reviewed to extract pregnancy (pregnancy-induced hypertension , preterm labor with hospitalization , and preterm delivery) and neonatal outcomes (low birthweight , small for gestational age, and admission to the neonatal intensive care unit). The study was conducted at an outpatient maternal and child health clinic at a 111), university teaching hospital. A total of 384 white (n African An1erican (n = 151), and Mexican American (n = 99) adolescents , aged 12 to 17 years , who initiated care between January 2, 1992, and December 31, 1994, and delivered an infant at our institution were consecutively sampled. A structured interview assessed various health-risk behaviors including age at first intercourse , substance use (tobacco , alcohol, and other illicit drug use) , and nlunber of sexual partners. Medical records were reviewed to obtain information on pregnancy complications (pregnancy-induced hypertension , preterm delivery , and preterm labor with hospitalization) and negative birth outcomes (infant birthweight and neonatal intensive care admission). Results: Controlling for chronological age, logistic regression analyses found that adolescents reporting employment at their first prenatal visit (n = 40) compared with those not employed at this visit (n = 331) were more likely to be characterized by school enrollment , higher econon1icstatus, partner employment , partner alcohol use , and a longer relationship with the father of their baby. Multivariate logistic regression found that employed females were 4.6 times more likely to deliver a small-for-gestational-age infan t.
Presented in p 訂t at the 10th annual meeting of the North American Society for Pediatric and Adolescent Gynecology , SanDiego , California, May 17, 1996. Address reprint requests to: V. J. Ricke此， PsyD , Division of Pediatric and Adolescent Gynecology , 301 University Boulevard, Galveston , Texas 77555-0587. 1083-3188 © 1998 Lippincott-Raven Publishers
Conclusions: Employment reported at the time of the first prenatal visit does not appear to be associated with an increase in health-risk behaviors or obstetric complications , but a relationship between working more than 15 hours and small-forgestational-age delivery was detected.
Key Words. Pregnancy一-Adolescent-Employment Health-risk behaviors-Obstetric complicationsNeonatal outconles
Introduction Employment is a significant and often essential factor in the lives of many adolescents. 1- 5 Nationally collected data suggest that roughly two thirds of high school seniors and half of high school sophomores hold part-time jobs while going to school? Benefits of part-time employment include money for personal or family use , enhanced feelings of competence and independence , and family approval. 1 Unfortunately , the advantages of employment for adolescents who work more than a few hours per week may be outweighed by certain increases in health-risk behaviors. Several studies suggest that those adolescents who work in excess of 15 hours per week are at greater risk for substance use , dropping out of school , and delinquency.3-8 For example , among a large sample of 15- to 18-year-olds , an increase in work hours was associated with poorer school performance , increased use of alcohol , decreased family contacts , and cynical attitudes toward work. 3 Despite increasing numbers of adolescent females entering the workforce ,9 , 10 research examining the health effects of employment on young women has been minimal. It has been reported that stressful work is related to alcohol and marijuana use for both male and female adolescents , but only among girls is it related to increased
80
Rickert et al: Employment and Adolescent Pregnancy
rates of school absenteeism. 4 Moreover, Whitehead and Layne 11 found higher rates of heavy drinking among employed female adolescents aged 15 to 19 years than among same-aged employed male adolescents (29% v 17%). These data have important implications for employed female adolescents who become pregnant because many young gravidas face higher obstetric risks caused by adverse nutritional , socioeconomic , and behavioral factors. 12- 14 Thus , the association between employment and health-risk behaviors during some or all of the adolescent' s pregnancy requires evaluation and has not been examined within this population. As a first step in filling this void , we compared healthrisk behaviors of pregnant adolescents who reported employment more than 15 hours per week with those young gravidas who did not report working at their first prenatal visi t. We hypothesized that working teens would report significantly higher rates of substance use and other health-risk behaviors. In addition , we examined rates of pregnancy complications and negative birth outcon1es between these two groups , as past research among adult employed women has demonstrated increased rates of premature delivery , 15 , 16 low birthweight, 17 and spontaneous abortion. 18
Materials and Methods Those eligible to participate in the present investigation were adolescents less than 18 years of age who initiated prenatal care at The University of Texas Medical Branch at Galveston Adolescent Obstetrics Clinic between January 2, 1992, and December 31 , 1994; completed a structured interview at the time of their first prenatal visit (mean , 15.5 weeks; SD , 7.8 weeks); and delivered an infant at our institution (n 384). These facilities primarily serve a tri-ethnic adolescent population (white , Mexican American , and African American) whose families live at or below the poverty leve l. As part of standard care , adolescents were asked at their first prenatal visit to complete a structured interview by one of two trained female clinic assistants. The structured interview was adapted from measures previously published in the adolescent literature and piloted with a small number of adolescents. Information on age , race , school enrollment , number of hours worked per week , and household composition was elicited. Standardized questions on health-risk behaviors included age at first intercourse , substance use (tobacco , alcohol , and other illicit drugs) during the last 12 months and since their last menstrual period , as well as lifetime number of sexual partners. In addition , each subject was asked to provide information about the father of her baby , including his employment status , the length of their relationship , and the weekly frequency of his alcohol and other drug use. Although subjects were consecutively inter-
viewed , 8% of females who received care were not interviewed because of scheduling difficulties. With institutional review board approval , a trained research assistant extracted the following data from subjec t' s medical record: financial status; reproductive history; results of urine drug screens (cannabinoids , cocaine , and opiates) conducted at the first prenatal visit; examination results for sexually transmitted disease and sonography; fetal birth weight; gestational age at delivery; occurrence of pregnancy-induced hypertension , neonatal intensive care admission , preterm delivery , preterm labor with hospitalization , and whether the infant was small for gestational age from the subjec t' s and her infan t' s medical records. Data Definitions Subjects were considered employed at the time of their first prenatal visit if they reported working outside the home more than 15 hours per week. Thirteen subjects who reported employment but worked 15 hours per week or less were excluded from subsequent analyses. Living with a parent and use of tobacco , alcohol , or marijuana during the last 12 months and use since the last menstrual period were all coded as "yes" or '‘ no." Tobacco and alcohol use was based on self-report; however, marijuana and other illicit drug use was based on both self-report and urine drug screens that were conducted on 95% of subjects sampled. Thus , drug use was confirmed if either the subjec t' s urine drug screen was positive or she selfreported use. Number of lifetime sexual partners was categorized as 石2 or >3. Based on reports by the pregnant adolescent, partner employment was coded as either "yes" or "no ," whereas weekly use of alcohol and other illicit drugs was coded as none , 1-2, and>2 times per week. Finally , length of relationship with this male partner was treated as a continuous variable and was measured in months. Using routinely collected financial information , economic status was defined as either 0%-100% or >100 0/0 of the federally established poverty level based on the adolescent' s self-report of the family' s household income and the number of household members dependent on that income. Reproductive information obtained from the medical record was dichotomized and included parity (0 or ~ 1), gravidity (逗 1 or >1), and number of past abortions (0 or ~ 1). Participants were screened for sexually transmitted disease (gonorrhea, chlamyd間， syphilis , and condylomatous lesions). Maternal complications examined included pregnancy-induced hypertension , preterm labor with at least one day of hospitalization , and cesarean section and were coded as present if the subject's medical record confirmed these complications. Small-for-gestational age was defined as a birthweight that was below the 10th percentile for gestational age according to the Brenner scale. 19 Consistent with the clinical literature , those infants who weighed less than
Rickert et al: Employment and Adolescent Pregnancy 2500 g were considered low birthweight. Finally , admission to the neonatal intensive care unit was coded as “ yes" or "no." Premature birth was coded "present" if the gestational age at delivery was less than 37 weeks. Fewer than 8% of the subjects had missing data for any outcome evaluated.
81
many covariates included in the model as the sample size would permit, and the contribution of individual covariates to the model was exan1ined as each was added to or removed from these analyses.
Results Statistical Analysis Analyses were first conducted to examine the effects of employment on health-risk behaviors , and , second, to examine the effects of employment on maternal and neonatal outcomes. Demographic , reproductive , and healthrisk behaviors were compared among patients stratified by employment (employed >15 hours per week versus not employed) using X2 or Student' s t-tests , depending on the level of measuremen t. Bivariate correlates (石 0 . 1 0) were then considered for entry into stepwise logistic regression analyses to identify health-risk behaviors independently associated with employment. Next，χ2 analyses were used to compare the prevalence of maternal and neonatal outcomes between employed and nonemployed adolescents. The relative risk of complications among employed versus nonemployed adolescents was estimated by calculating odds ratio and 95% confidence limits (95% CL). Stratified analyses were performed to identify data-specific confounders. We then conducted logistic analyses to a句ust the relative risk of each maternal and neonatal outcome among employed and nonemployed adolescents. Variables known to be related to outcomes , such as estimated gestational age at entry into prenatal care , smoking prepregnant weight , weight gain during pregnancy , parity , height , 11 and other confounders identified from these stratified analyses were used in these analyses to control for these effects. Unfortunately , it was not possible to simultaneously enter all covariates into multivariate analyses for each outcome because of the small sample size. Thus , logistic regression analyses were conducted , with as
A total of 40 adolescents reported working more than 15 331) reported not hours per week , whereas 86% (n working at the time of their first prenatal visi t. Twentythree (58%) of the employed adolescents worked 16 to 20 hours , 10 (25%) worked 21 to 28 hours , and the remaining 7 (17%) worked 30 or more hours. Most working adolescents in our sample were employed in the food service industry (fast-food , waitress , or hostess) or retail stores (cashiers or salespersons). Employed compared with nonemployed female adolescents were older (16.6ν15.8 years~ p < 0.01) , reported a higher economic status (30%ν16%~ p < 0.01) , were more likely to report that their partner was also employed (74% v 49%~ p < 0.01) , and a longer ongoing relationship with their baby's father (20 v 14 months~ p < 0.01). As can be seen in Table 1, reproductive characteristics , race/ ethnicity , and living arrangements did not differentiate employed from nonemployed gravidas. Differences in health-risk behaviors were detected among employed and nonemployed teenagers (Table 2). Subjects who worked more than 15 hours per week were more likely to report school enrollment and to have experienced first intercourse after the age of 14 years~ however, no differences in the number of lifetime sexual partners were found between these groups. Although en1ployed females had fewer confirmed sexually transmitted diseases during pregnancy (14% v 23%) , this finding was nonsignificant. Substance use including use of tobacco , alcohol , and marijuana since their last menstrual period did not differ between these groups of subjects.
Table 1. Selected Demographic Characteristics of Employed Versus Not Employed Adolescents
No.
%
No.
%
Gravidity (>1) Parity (~1) Abortion (注 1 ) Ethnicity White African American Mexican American Other Economic status (>100% of poverty level) Living with parent Current relationship with baby' s father Partner employed
8 4 4
20 10 10
85 39 20
26 12 4
15 16 8
38 40 22 2 30 71 90 74
96 135 91 9 41 210 257 148
29 41 27 3 16 64 78 49
Abbreviation: NS, not significan t.
12 30 36 26
d-sss u-
NS
0.01
NS 0.07 0.01
戶L V -
Demographic Characteristic
P 一
NotEmployed (n = 331) 訊 -N N N
Employed (n = 40)
82
Rickert et al:
Employment and Adolescent Pregnancy
Table 2. Selected Risk Behaviors of Employed Versus Not Employed Pregnant Adolescents Employed (n = 40)
Not Employed (n = 331)
Demographic Characteristic
No.
%
No.
%
p Value
Enrolled in school Age at first intercourse (>14) No. of lifetime p訂tners (>1) Discussed birth control with partner Current pregnancy not planned Substance use during last 12 months Tobacco Alcohol Marijuana Substance use since last menstrual period Tobacco Alcohol Marijuana Partner alcohol use (weekly) None 1-2 times >2 times Partner drug use (weekly) None 1-2 times >2 times
33 26 30 29 36
82 65 75 74 95
231 132 212 183 270
69 40 64 57 85
0.09 0.01 NS 0.03 0.10
10 21 5
26 62 13
72 127 41
24 46 13
NS 0.07 NS
5 7 11
13 19 29
39 58 68
13 19 22
NS NS NS 0.10
10 17 9
28 47 25
141 111 53
46 36 17
26 7 5
70 18 12
259 26 22
84 9 7
0.04
Abbreviation: NS , not significan t.
Finally , weekly frequencies of alcohol (p - 0.10) and illicit drug use (p == 0.04) were higher among partners of employed conlpared with partners of nonemployed fenlale adolescents. Stepwise logistic regression analyses revealed that when controlling for age , five variables were significantly associated with being employed more than 15 hours (Table 3). Adolescents who were employed were more likely to be enrolled in school , have a partner who was enlployed , report a higher economic status , report more frequent alcohol use by their male partner , and have a longer relationship (measured in months). Thus , for every 6-month increase in the female's relationship with her partner , we found a 24% increase in the likelihood she was employed more than 15 hours per week. Multivariate analyses controlling for the effects of gestational age at entry into care and other confounders Table 3. Logistic Regression Model of Factors Associated With Employment Variable
Adjusted Odds Ratio
95% CL
School enrollment Economic status (> 100% of poverty leve l) Frequency of alcohol use by P訂tner Partner employed Length of relationship (mo)
3.57 3.24
1.32 , 9.61 1.20 , 8.76
2.04
1.16 , 3.59
3.31 1.04
1.29 , 8.5 1 1.01, 1.08
Total sample is comprised of 293 because of missing data across variabIes by some subjects. Abbreviation: CL , confidence lin1its.
found only one significant difference in maternal and neonatal complications between employed versus nonemployed young patients. Employed adolescents were 4.6 times more likely (CL: 1.1, 19.3) to deliver a smallfor-gestational-age infant compared with nonemployed gravidas when controlling for estimated gestational age at entry into prenatal care , height , race , parity , history of preterm labor , alcohol and illicit drug use , smoking , and low birthweight (p < 0.03). No differences were found between these two groups for rates of pregnancy-induced hypertension , preterm labor , cesarean section , low birthweight , or preternl delivery.
Discussion Contrary to our expectations and to trends in the research literature , these young gravidas , compared with their nonemployed peers , did not have increased rates of health-conlpromising behaviors , such as tobacco , alcohol and other drug use or high-risk sexual behaviors. In fact , employment reported at the first prenatal visit was strongly related to school involvement, as working adolescents were 3.5 times more likely to be enrolled in schoo l. Perhaps these working female adolescents represent a more mature , goal-directed group of adolescents than their younger , unemployed counte中arts. As such , they may perceive greater benefit from staying in school and may be somewhat immune to the detrimental effects on school performance that nonpregnant samples of working adolescents have reported 3 人 7，8 ; however , future
Rickert et al: Employment and Adolescent Pregnancy research with pregnant working adolescents must examine changes in school status throughout the pregnancy to test the relationships observed in our study. We did not find increased rates of harmful or illicit substance use since last menstrual period or within the past 12 months among employed compared with nonemployed pregnant female adolescents~ however , we found a trend for higher rates of alcohol use within the past 12 months and that the male partners of employed females used both alcohol and other illicit drugs n10re frequently than the male partners of nonemployed females. Thus , despite easy availability and the monetary resources to purchase these substances , our subjects may have understood the dangers associated with substance use during pregnancy. These findings are consistent with previous reports documenting decreased rates of alcohol use during adolescent pregnancy?O,2 1 Another important finding in our study was that employed teens reported a higher economic status. Specifically , employed adolescents were much more likely to report living above the poverty leve l. Because economic status was determined from the adolescent' s self-report of family income , these results must be interpreted with caution. Nevertheless , many of these young gravidas still lived with a parent and had a male partner who was also employed. In addition , employed adolescents , on average , reported a longer relationship with their male partner (20 v 14 months). The length and perhaps stability of this relationship likely contributed to increased psychological support during their pregnancy. Thus , the families' financial and psychological resources may have provided a distinct advantage for these young gravidas , 的 pri or research among pregnant adolescents suggests that those with these support mechanisms have fewer pregnancy complications. 22 ,23 As a result , these economic and psychological advantages may have contributed to the healthy maternal and neonatal outcomes observed in this study. Although we inquired about employment and the number of hours worked only at the first prenatal visit , our association between employment early in the pregnancy and delivery of a small-for-gestational-age infant is of interest but must be interpreted with caution. Henriksen et al 24 found that employn1ent during specific periods of gestation has differential effects on th
83
example , most reported working as fast -food clerks or cashiers , which frequently involve standing for prolonged periods. Alternatively , erratic eating habits or stress of both working and attending school may have played a significant role in this perinatal outcome~ however, these reasons are speculative , and further research is required as we do not know how long into their pregnancy our females maintained their employment nor the type and amount of physical labor required. Limitations of the present study should be acknowledged. First, all adolescents in our sample obtained prenatal care at some point during their pregnancy. Healthrisk behaviors as well as maternal and neonatal outcomes may be quite different an10ng those employed pregnant adolescents who do not seek medical care during pregnancy. Second , most research in this area , including ours , relies on cross-sectional data and , as such , provides a limited picture of the health-risk behavior-employment relationship.6 Future research must n10re carefully examine this relationship using longitudinal designs to better establish the effects of both pregnancy and gender among working adolescents. Clinically , these preliminary data suggest that pregnant adolescents who work more than 15 hours at the time of their first prenatal visit are not more likely to engage in health-risk behaviors than adolescents who do not report working. Health care providers should obtain a detailed history relative to both the physical and psychological aspects of employment to carefully evaluate the risk of maternal and neonatal complications. Employed pregnant adolescents , particularly those who are enrolled in school , may represent a unique group of young won1en who are motivated to better their life situation and that of their unborn child. While their determination to work should be supported , their hectic schedules and erratic , eating habits may affect their developing fetuses. Thus , the fetal growth parameters of these young women may require close attention because of the demands placed on them by school and employment in conjunction with other nutritional , socioeconomic , and medical factors that may cause fetal growth restriction.
Acknowledgments. For editorial and graphic assistance, we
thank R.G. McConnelland the Obstetricsand Gynecology Publications staff, Kristi Barrett, John Helms, and Steve Schuenke.
References 1. Fine GA, MortimerJT, Roberts DF: Leisure, work, and the
mass media. In: At the Threshold: The Developing Adolescent. Edited by SS Feldman, GR Elliott. Carrlbridge , MA, Harvard University Press, 1990 , p 225 2. Crockett LJ , Petersen AC: Adolescent development: Health risk and opportunities for health promotion. In: Pro-
84
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15. 16.
Rickert et al:
Employment and Adolescent Pregnancy
moting the Health of Adolescents. Edited by SG Millstein , AC Petersen , EO Nightingale. New York , Oxford University Press , 1993, p. 13 Steinberg L , Dornbusch SM: Negative correlates of parttime employment during adolescence: replication and elaboration. Dev Psychol 1991; 27:304 Kablaoui BN , Pautler AJ: The effects of part-time work experience on high school students. J Career Dev 1991; 17:195 Greenberger E , Steinberg L: When Teenagers Work: The Psychological and Social Costs of Adolescent Employment. New York , Basic Books , 1986 Roman PM , Johnson JA: Alcoho l's role in work-force entry and retiremen t. Alcohol Health Res World 1996; 20: 162 Steinberg L , Greenberger E , Garduque L , et al: High school students in the labor force: some costs and benefits to schooling and learning. Educational Evaluation and Policy Analysis 1982; 4:363 Steinberg L , Greenberger E, Garduque L, et al: Effects of working on adolescent developmen t. Dev Psychol 1982; 18:385 U.S. Department of Labor. In: Handbook of Labor Statistics. Bureau of Labor Statistics , Bulletin 2340. Washington , DC, US Government Printing Office , 1989, P 257 Barling J , Rogers KA , Kelloway ER: Some effects of teenagers' part-time employmen t: the quantity and quality of work make the difference. Journal of Organization Behavior 1995; 16:143 Whitehead PC , Layne N: Young female Canadian drinkers: employment , marital status , and heavy drinking. British Journal of Addiction 1987; 82:169 US Congress , Office of Technology Assessmen t: Adolescent Health-Volume 2: Background and the Effectiveness of Selected Prevention and Treatment Services , OTA-H466. Washington , DC , US Government Printing Office , November 1991, pp 62-64 , 526 Stevens-Simon C , McAnarney ER: Adolescent pregnancy. In: Handbook of Adolescent Health Risk Behavior. Edited by RJ DiClemente , WB Hansen , LE Ponton. New York , Plenum Press , 1996, p 313 Seitz V , Apfel NH: Effects of school for pregnant students on the incidence of low-birthweight deliveries. Child Dev 1994; 65:666 Colie CF: Preterm labor and delivery in working women. Semin Perinatol 1993; 17:37 McDonald AD , McDonald JC , Armstrong B, et al: Prema-
turity and work in pregnancy. Br J Industr Med 1988; 45: 56 17. Naeye RL , Peters EC: Working during pregnancy: effects on the fetus. Pediatrics 1992; 69:724 18. McDonald AD ， 孔1cDonald JC , Armstrong B , et al: Fetal death and work in pregnancy. Br J Industr Med 1988; 45: 148 19. Brenner WE , Edelnlan DA , Hendricks CH: A standard of fetal growth for the United States of America. Am J Obstet Gynecol 1976; 126:555 20. Zuckerman BS , Alpert 刃， Dooling E , et al: Neonatal outcome: is adolescent pregnancy a risk factor? Pediatrics 1983; 71:489 2 1. Gilchrist LD , Gillmore MR , Lohr MJ: Drug use among pregnant adolescents. In: Adolescent Substance Abuse: Etiology , Treatment , and Prevention. Edited by GW Lawson, AW Lawson. Gaithersburg , MD , Aspen Publication , 1992, P 351 22. Giblin PT , Poland ML , Sachs BA: Effects of social supports on attitudes and health behaviors of pregnant adolescents. J Adolesc Health 1987; 8:273 23. Pazarine S: Stressors , coping , and social supports of adolescent mothers. J Adolesc Health 1986; 7:153 24. Henriksen TB , Savitz DA , Hedegaard M , et al: Employment during pregnancy in relationship to risk factors and pregnancy outcome. Br J Obstet Gynaecol 1994; 101:858 25. Moss N, Carver K: Pregnant women at work: Sociodemographic perspectives. Am J Ind Med 1993; 23:541 26. Henriksen TB , Hedegaard M, Secher NJ: Standing and walking at work and birthweigh t. Acta Obstet Scand 1995; 74:509 27. Seneviratne SR, Fernado DN: Influence of work on pregnancy outcome. Int J Gynecol Obstet 1994; 45:35 28. Chamberlain GV: Work in pregnancy. Am J Ind Med 1993; 23:559 29. Klebanoff MA , Shioro PH , Carey JC: The effect of physical activity during pregnancy on preterm delivery and birthweigh t. Am J Obstet Gynecol 1990; 163:1450 30. Clapp III JF: Pregnancy outcome: physical activities inside versus outside the workplace. Semin Perinatol 1996; 20:70 3 1. Teitelman AM , Welch LS, Hellenbrand KG , et al: Effect of maternal work activity on preterm birth. Am J Epidemiol 1990; 131:104 32. Mamelle N, Laumon B, Laumon B , Lazar P: Prematurity and occupational activity during pregnancy. Am J Epidemiol 1984; 119:309