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Excessive maternal weight gain patterns in adolescents
RESEARCH AND PROFESSIONAL BRIEFS
Excessive maternal weight gain patterns in adolescents LAJEANA D. HOWIE, MPH; JENNIFER D. PARKER, PhD; KENNETH C. SCHOENDORF, MD, MPH
ABSTRACT The objective of this study was to examine the correlates of excessive maternal weight gain among adolescent mothers in the United States. Data from the Centers for Disease Control & Prevention 2000 natality file were analyzed to examine weight gain among adolescents (ⱕ19 years) compared with their older counterparts (ⱖ20 years). Using the Institute of Medicine guidelines, we defined excessive weight gain as more than 40 pounds. Our study population was restricted to singleton births, delivered after 36 weeks of gestation, who did not live in California. Maternal weight gain distributions were tabulated by maternal age and other maternal characteristics. Demographic characteristics potentially associated with maternal weight gain were compared for adolescents and older mothers. We further evaluated the role of parity and maternal race on the relationship between excessive weight gain and maternal age. Odds ratios and 95% confidence intervals were estimated using logistic regression. Over 27% of adolescent mothers gained excessive weight during pregnancy, although approximately 18% of their older counterparts gained more than 40 pounds. The association between young maternal age and weight gain was stronger for primiparous women than multiparous women and stronger among non-Hispanic white and non-Hispanic black mothers than Hispanic mothers. Adolescents were more likely to gain excessive weight than their older counterparts in nearly all demographic categories, regardless of parity or race. Adolescents are at high risk of gaining an excessive amount of weight during pregnancy and should be monitored during pregnancy by dietetics professionals. J Am Diet Assoc. 2003;103:1653-1657.
xcessive maternal weight gain has been associated with many pregnancy-related health risks, including labor and delivery complications, maternal anemia, preterm labor, macrosomia, and infant mortality (1-3). In addition, postpartum weight retention, a direct consequence of excessive maternal weight gain, can lead to obesity (2,4,5). Obesity increases a woman’s risk of major health problems, including hypertension, heart
E
disease, diabetes, and some types of cancers (6-9). Obesity affects the health status of many women and is steadily increasing in women of reproductive age (4,5,10). Obesity is a major public health concern, and reducing the proportion of adults who are obese has been listed as one of Healthy People 2010’s objectives (11). Research comparing maternal weight gain differences in adolescents and older
L. D. Howie is a health statistician, J. D. Parker is a health research scientist, and K. C. Schoendorf is chief, Infant and Child Health Studies Branch, Centers for Disease Control and Prevention, National Center for Health Statistics, Hyattsville, MD. Address correspondence to: LaJeana D. Howie, MPH, Centers for Disease Control and Prevention, National Center for Health Statistics, 3311 Toledo Rd, Room #6105, Hyattsville, MD 20782. E-mail: [email protected] Copyright © 2003 by the American Dietetic Association. 0002-8223/03/10312-0011$30.00/0 doi: 10.1016/j.jada.2003.09.040
mothers has shown that adolescents gain more weight during pregnancy than their older counterparts (4,8,12,13). Increased maternal weight gain in adolescents compared with older women has been attributed, in part, to the adolescent body working to meet the needs of its own growth in addition to the needs of the growing fetus (13-15). As a result, some of the increased maternal weight gain in adolescents may be associated with increased birth weights of infants and more favorable pregnancy outcomes (1,16,17). However, there is evidence that adolescent mothers with excessive maternal weight gain have a greater tendency to retain excess weight postpartum (18). Previous studies have found that primiparas, mothers pregnant with their first infant, are more likely to gain an excessive amount of weight during pregnancy than multiparas (19). Because adolescents are primarily primiparous (19), it is unclear how much of the excessive maternal prenatal weight gain observed among adolescents is because of primiparity rather than age. Adolescents who gain an excessive amount of weight during their first pregnancy may retain some of this weight and continue to gain weight with each subsequent pregnancy. Understanding the relative contributions of age and parity on prenatal weight gain may be important for determining how to best prevent obesity among adolescent mothers (19). In addition, studies have shown that a relationship exists between race/ethnicity and maternal weight gain. For example, white mothers are more likely to gain an excessive amount of weight during pregnancy than black mothers (20). Furthermore, studies have also shown that a relationship exists between race/ethnicity and maternal age. For example, white mothers are more likely to have children at a later age than black or Hispanic women (21). However, the importance of race/ethnicity on the relationship between age and maternal weight gain is unknown. The purpose of this study was to examine the correlates of excessive maternal weight gain among adolescent mothers in the United States, using 2000 natality data. Most studies on maternal weight gain in adolescents have relied on clinical populations and are not nationally representative. Although it is known that adolescent mothers gain more weight than their older counterparts, this study provides a recent national per-
Journal of THE AMERICAN DIETETIC ASSOCIATION / 1653
RESEARCH AND PROFESSIONAL BRIEFS
Table 1 Distribution and percent high maternal weight gain (⬎40 lb) of singleton births, by selected maternal characteristics, CDC natality file 2000a Maternal characteristics Maternal age (yr) ⱕ15 16-17 18-19 20-24 25-29 30-34 35-39 40 or older Parity Primipara Multipara Race/ethnicity Non-Hispanic black Hispanic or Latina Non-Hispanic white Other groups Educationc Adequate Inadequate Gestational age (wk) 37 38 39 40 41 42 or more Region Northeast Midwest South West
Study sample
%
% high maternal weight gainb
18,619 89,639 215,089 711,343 764,150 641,426 298,583 57,956
0.7 3.2 7.7 25.4 27.3 22.8 10.7 2.1
28.7 27.8 26.7 21.6 18.6 16.2 14.5 12.8
1,145,042 1,651,763
40.9 59.1
24.9 15.3
415,958 417,744 1,831,322 131,781
14.9 14.9 65.5 4.7
16.1 19.4 20.3 14.6
2,306,677 490,128
82.5 17.5
19.3 19.2
247,822 517,449 773,117 676,693 349,472 232,252
8.9 18.5 27.6 24.2 12.5 8.3
16.5 17.5 18.4 20.2 22.2 22.2
554,363 737,676 1,159,764 345,002
19.8 26.4 41.5 12.3
18.7 19.9 19.2 19.1
a Study population limited to mothers delivering singletons with known maternal weight gain, gestational age, parity, education, race, and age. Births to California residents were excluded. b Associations between percent high weight gain and maternal characteristics are all statistically significant, P⬍.01. c Education is considered adequate for mothers 18 years of age and older who completed high school and for those under 18 years of age if schooling was six or fewer years less than their age.
spective on the pregnancy weight gain of these mothers. METHODS The 2000 US natality file compiled by the Centers for Disease Control and Prevention, National Center for Health Statistics, has information for all birth records from all states and the District of Columbia. Our study population was restricted to singleton births of infants delivered after 36 weeks of gestation. California does not collect information on maternal weight gain; therefore, births to California residents were excluded from this analysis (531,959) (21). Birth records missing information for maternal weight gain (7.2%), gestational age (1.1%), parity (.4%), or education (1.4%) were also excluded. The final study population consisted of 2,796,805 births. Current weight gain guidelines, which differ by prepregnancy body mass index 1654 / December 2003 Volume 103 Number 12
(BMI), were issued by the Institute of Medicine (IOM) in 1990. The guidelines recommend pregnant women of low prepregnancy BMI gain between 28 and 40 pounds, women of normal BMI gain 25 to 35 pounds, and women with a high BMI gain 15 to 25 pounds. Adolescents are encouraged to gain weight at the upper end of the spectrum (5,22). Unfortunately, birth certificates did not collect information on maternal height or prepregnancy weight, preventing the calculation of prepregnancy BMI. Because 40 pounds is the highest amount of weight that anyone should gain during pregnancy, regardless of age or BMI, excessive weight gain was defined as greater than 40 pounds. Maternal weight gain was divided into two categories, 40 pounds or less, and greater than 40 pounds. Maternal age, the focus of our study, was separated into eight categories,
⬍15, 16 to 17, 18 to 19, 20 to 24, 25 to 29, 30 to 34, 35 to 39 and 40 years or older. The adolescents were considered to be 19 years of age or younger, although we examined them in smaller age categories. Factors that are known to be associated with both maternal age and prenatal weight gain in the United States were included in the analysis. Parity was divided into two groups, either first or subsequent birth. Higher parity was not considered separately in our analysis because the focus of the study was on adolescents. To examine weight gain differences by maternal race and ethnicity, we created a composite variable: Hispanic, non-Hispanic black, non-Hispanic white, and other groups. Although we had too few adolescent mothers in the other race groups for stable analysis and this is a heterogeneous group, these mothers were retained for tabulations by other maternal characteristics, but not discussed separately. The standard definitions of education were not appropriate for adolescents, who may have not had the opportunity to finish high school. Therefore, we defined education as either adequate or inadequate for age. All women who were 18 years of age or older and completed high school were considered to have adequate education for their age. Mothers less than 18 years of age were considered to have adequate education if their year of schooling was 6 years less than their age or higher (23). Because our study examines total weight gain, limiting the study to term deliveries reduces, although does not eliminate, the bias from differential length of pregnancy. Gestational age was also included as a potential confounder of the association between maternal age and weight gain because women with longer pregnancies have had more time to gain more weight. Gestational age was defined as the number of weeks from the last menstrual period to delivery. Region was separated into four categories, Northeast, Midwest, South, and West. STATISTICAL ANALYSIS All statistical analysis was performed using the Statistical Analysis Software (SAS 8.2, 1999-2001; SAS Institute Inc., Cary, NC). First, the weight gain distribution was tabulated by maternal age and other maternal characteristics. Second, excessive weight gain among adolescent mothers was retabulated by maternal characteristics. Logistic regression models were used to examine the relationship between maternal age and
RESEARCH AND PROFESSIONAL BRIEFS
Table 2 Percent high maternal weight gain (⬎40 lb) by maternal age and other maternal characteristics, CDC natality file 2000a Maternal characteristics
Race/ethnicity Non-Hispanic black Hispanic or Latina Non-Hispanic white Other groups Parity Primipara Multipara Educationc Adequate Inadequate Gestational age (wk) 37 38 39 40 41 42 or more Region Northeast Midwest South West
Maternal ageb ≤15 y Nⴝ18,619
16-17 y Nⴝ89,639
18-19 y Nⴝ215,089
20ⴙ y Nⴝ2,473,458
26.0 24.7 35.5 29.0
22.7 22.6 33.7 26.9
20.4 22.2 31.2 24.8
15.0 18.6 19.2 13.7
29.1 14.5
29.1 16.2
30.0 16.9
23.5 15.3
28.8 28.6
28.0 27.6
28.0 25.2
18.5 16.4
21.8 26.3 27.0 29.8 34.0 34.2
22.4 23.9 26.6 29.3 32.4 32.1
21.5 23.5 25.4 27.9 30.8 30.6
15.8 16.7 17.5 19.1 20.7 20.5
29.6 31.4 27.3 28.7
27.9 30.3 26.4 28.4
27.2 28.6 25.4 27.3
18.0 18.8 18.1 17.9
a
Study population limited to mothers delivering singletons with known maternal weight gain, gestational age, parity, education, race, and age. Births to California residents were excluded. Associations between percent high weight gain and maternal characteristics are all statistically significant, P⬍.01. c Education is considered adequate for mothers 18 years of age or older who completed high school and for those under 18 years of age if schooling was six or fewer years less than their age or higher. b
excessive weight gain, controlling for the potentially confounding effects of maternal race/ethnicity, education, parity, region, and gestational age. We also observed that the relationship between maternal age and weight gain varied by race/ethnicity and parity. We then fit separate logistic models for non-Hispanic white, non-Hispanic black, and Hispanic mothers by parity to further examine these relationships. RESULTS Adolescents were more likely to gain an excessive amount of weight during pregnancy compared with older women (Table 1). Women having their first birth were considerably more likely to gain excess weight than those having subsequent births. Non-Hispanic white women were more likely to gain an excessive amount of weight during pregnancy compared with all other race/ethnicity categories. The excessive weight gain was similar among mothers with adequate and inadequate education and among regions of the country. As expected, excessive weight gain generally increased with gestational age. Table 2 presents the percentage of mothers with excessive weight gain by
maternal age and other maternal characteristics. Adolescent mothers in the three age groups were more likely than those in the older mothers age group to gain an excessive amount of weight in nearly every category. The relationships between maternal age and excessive weight gain were also generally stronger among the younger adolescents compared with the older adolescents. Table 3 shows the unadjusted and adjusted odds ratios and their corresponding 95% confidence intervals for excessive weight gain. Compared with mothers 25 to 29 years of age, the risk of high maternal weight gain was highest for adolescents 15 years of age or younger. The risk of high maternal weight gain decreased as maternal age increased. When other variables were added to the model, the magnitude of the association between maternal age and excessive weight gain decreased, but the adolescents 15 years of age or younger continued to be more likely to gain an excessive amount of weight during pregnancy. Primiparous women were more likely to gain an excessive amount of weight than multiparous women, although the association between parity and weight
gain decreased after adjustment for other maternal factors. After adjustments, the odds ratio for non-Hispanic black and Hispanic women decreased slightly. The odds ratio for women who have inadequate education decreased, and the odd ratios for gestation and region were similar, after adjustments to the model. Given the seeming differences between age and maternal weight gain by both parity and race/ethnicity, shown in Table 2, we created stratified models to examine whether the association differed by these factors (Table 4). The relationship between maternal age and excessive weight gain was strongest among non-Hispanic white primiparous adolescents after adjusting for the other maternal factors. Among multiparous women, there was little difference in excessive weight gain by age, regardless of race/ ethnicity. DISCUSSION Similar to other studies, we found that adolescents were more likely to gain an excessive amount of weight during pregnancy than their older counterparts (4,8,12,13). Over 27% of adolescents exceeded the absolute IOM weight gain
Journal of THE AMERICAN DIETETIC ASSOCIATION / 1655
RESEARCH AND PROFESSIONAL BRIEFS
Table 3 Unadjusted and adjusted odds ratios (OR) and 95% confidence intervals (CI) for association between high maternal weight gain (⬎40 lb) and maternal characteristics, CDC natality file 2000a
Maternal age (y) ⱕ15 16-17 18-19 20-24 25-29 30-34 35-39 40 or older Race/ethnicity Non-Hispanic black Hispanic or Latina Non-Hispanic white Other groups Parity Primipara Multipara Educationc Adequate Inadequate Gestational age 37 38 39 40 41 42 or more Region Northeast Midwest South West
Unadjusted OR (95% CI)
Adjustedb OR (95% CI)
1.75 (1.70-1.81) 1.29 (1.28-1.30) 1.16 (1.16-1.17) 1.04 (1.04-1.05) Reference 0.96 (0.96-0.97) 0.95 (0.95-0.95) 0.93 (0.93-0.94)
1.44 (1.39-1.49) 1.18 (1.17-1.19) 1.11 (1.11-1.11) 1.04 (1.03-1.04) Reference 0.97 (0.97-0.97) 0.96 (0.96-0.96) 0.94 (0.94-0.95)
0.75 (0.74-0.76) 0.97 (0.96-0.97) Reference 0.87 (0.87-0.88)
0.72 (0.71-0.72) 0.94 (0.94-0.95) Reference 0.87 (0.87-0.88)
1.83 (1.81-1.84) Reference
1.60 (1.59-1.61) Reference
Reference 0.99 (0.98-1.00)
Reference 0.95 (0.94-0.96)
0.87 (0.86-0.88) 0.96 (0.96-0.97) Reference 1.03 (1.03-1.04) 1.05 (1.05-1.06) 1.04 (1.04-1.05)
0.87 (0.86-0.88) 0.97 (0.97-0.98) Reference 1.02 (1.02-1.02) 1.03 (1.03-1.04) 1.03 (1.03-1.03)
0.97 (0.96-0.98) 1.02 (1.02-1.03) Reference 0.99 (0.99-1.00)
1.01 (1.01-1.02) 1.01 (1.01-1.02) Reference 1.01 (1.00-1.01)
a Study population limited to mothers delivering singletons with known maternal weight gain, gestational age, parity, education, race, and age. Births to California residents were excluded. b Adjusted for region, maternal age, parity, education, and gestational age. c Education is considered adequate for mothers 18 years of age and older who completed high school and for those under 18 years of age if year of schooling was six or fewer years less than their age or higher.
guidelines, regardless of BMI. Mothers 15 years of age or younger were the most likely to gain excessive weight during pregnancy. Potential explanations for this finding include the absence of proper prenatal care and nutrition advice during their pregnancy or the beneficial adaptation of nutritional intake or metabolic processes to enable both their own normal growth and that of their fetus. A large part of the overall disparity in excessive weight gain between adolescents and adults is because of differences in parity. Primiparous adolescents were substantially more likely to gain more than 40 pounds than were their adult counterparts. There was a minimal association between maternal age and excessive weight gain among multiparous mothers. Unfortunately, the birth certificate does not include information on maternal weight and height, preventing the 1656 / December 2003 Volume 103 Number 12
calculation of prepregnancy BMI. As a result, many mothers with gains considered high by IOM standards are not included in our high weight gain group. This could also be a compounded problem for a specific adolescent or older mother with two or more pregnancies because she may have higher prepregnancy weights. It has not been documented whether adolescents with excessive weight gain during pregnancy are more likely or less likely to gain an excessive amount of weight in subsequent pregnancies, although our results for multiparous women suggest that they are at decreased risk. There was potential for bias in our study associated with gestational age. It is known that adolescents are most likely to deliver their infants at an early gestational age and that weight gain tends to increase with gestational age. However, adolescents in our study gained more
weight during their pregnancies than their older counterparts regardless of gestational age. Therefore, our findings are most likely conservative, although we adjusted for gestational age in our regression models. Maternal weight gain data were missing for 7.2% of the eligible study population. Although the primary analysis excluded mothers with missing weight gain, given the large percent missing we examined the excluded births more closely. Younger and older mothers, nonHispanic black mothers, mothers from the West, and mothers with inadequate education were more likely to be missing weight gain data. The impact of missing data on our results depends on which mothers are missing data, which we know, and the weight gain patterns for these mothers, which we do not know. Because there was a relatively high percentage of weight gain data missing for mothers under 15 years of age, who are at highest risk of excessive weight gain, our findings for adolescents as a group might be conservative. However, the mothers under 15 years of age make up a small percentage of adolescent mothers. Despite our limitations, our study showed that adolescents gain an excessive amount of weight during pregnancy compared with older women, as noted in other articles (4,8,12,13). Although higher weight gains during adolescent pregnancy may be associated with better birth outcomes, they are also associated with subsequent health risks for the mother (17). Excessive weight gain during pregnancy can cause postpartum obesity, which can result in severe medical and psychosocial consequences, particularly for adolescent women (24,25). The potential beneficial and deleterious effects of excessive weight gain during pregnancy on maternal and infant outcomes and its contribution to postpartum obesity among adolescent mothers is an area that merits more in-depth study.
APPLICATIONS During prenatal care, dietitians should explain to pregnant adolescents the problems for the mother and infant that are associated with gaining an excessive amount of weight during pregnancy. ■ Adolescents require special attention from dietitians during their pregnancies because they tend to gain an excessive ■
RESEARCH AND PROFESSIONAL BRIEFS
Table 4 Adjusted odds ratios (OR) and 95% confidence intervals (CI) for association between high maternal weight gain (⬎40 lb) and age by parity and race/ethnicity, CDC natality file 2000a Race/ethnicity
Non-Hispanic white ⱕ15 16-17 18-19 20-24 25-29 30-34 35-39 40⫹ Non-Hispanic black ⱕ15 16-17 18-19 20-24 25-29 30-34 35-39 40⫹ Hispanic or Latina ⱕ15 16-17 18-19 20-24 25-29 30-34 35-39 40⫹
Parity Primipara adjustedb OR (95% CI)
Multipara adjustedb OR (95% CI)
1.75 (1.66-1.85) 1.29 (1.28-1.31) 1.17 (1.17-1.18) 1.07 (1.07-1.07) Reference 0.96 (0.95-0.96) 0.94 (0.94-0.94) 0.92 (0.92-0.93)
0.94 (0.52-1.71) 1.09 (1.04-1.14) 1.05 (1.04-1.06) 1.01 (1.01-1.02) Reference 0.97 (0.97-0.97) 0.96 (0.96-0.96) 0.95 (0.94-0.95)
1.42 (1.32-1.52) 1.11 (1.09-1.14) 1.05 (1.04-1.07) 1.01 (1.00-1.02) Reference 0.97 (0.96-0.98) 0.96 (0.95-0.98) 0.92 (90.89-0.94)
1.03 (0.66-1.60) 1.01 (0.96-1.07) 1.01 (0.99-1.03) 1.00 (0.99-1.01) Reference 0.99 (0.98-1.00) 0.98 (0.97-0.99) 0.98 (0.97-0.99)
1.12 (1.06-1.19) 1.02 (1.00-1.04) 1.04 (1.02-1.04) 1.03 (1.02-1.04) Reference 0.96 (0.95-0.97) 0.94 (0.93-0.95) 0.91 (0.89-0.93)
0.85 (0.59-1.22) 0.96 (0.91-1.00) 0.97 (0.96-0.99) 0.99 (0.99-1.00) Reference 0.99 (0.99-0.98) 0.98 (0.97-0.98) 0.96 (0.95-0.97)
a Study population limited to mothers delivering singletons with known maternal weight gain, gestational age, parity, education, race, and age. Births to California residents were excluded. b Models stratified by parity adjusted for race/ethnicity and maternal age by parity.
amount of weight during their pregnancies. References 1. Christine SA, Furey CH, Miller LK, Salmon RW, Vasilenko P. Weight gain during adolescent pregnancy. J Adolesc Health Care. 1988;9:286-290. 2. Scholl TO, Hediger M. Weight gain, nutrition, and pregnancy outcome; findings from the Camden study of teenage and minority gravidas. Semin Perinatol. 1995;19:171-180. 3. Giddens JB, Gup S, Krug SK, Tsang R, Miodovnik M, Prada JA. Pregnant adolescent and adult women have similarly low intakes of selected nutrients. J Am Diet Assoc. 2000;100:1334-1340. 4. Green GW, Karp RJ, Scholl TO, SmiciklasWright H. Postpartum weight change: How much
of the weight gained in pregnancy will be lost after delivery? Obstet Gynecol. 1998;71:701-707. 5. Cogswell ME, Scanlon KS, Schieve LA. Trends in pregnancy weight gain within and outside ranges recommended by the institute of medicine in a WIC population. Matern Child Health J. 1998; 2:111-115. 6. Haggerty M. Obesity. Gale Encyclopedia of Medicine. 1999;1:2075-2082. 7. Hediger ML, Salmon RW, School TO. Early weight gain in pregnant adolescents and fetal outcome. Am J Human Biol. 1989;1:665-672. 8. McAnarney ER, Segel JS. Adolescent pregnancy and subsequent obesity in African-American girls. J Adolesc Health. 1994;15:491-494. 9. Lederman SA, Alfasi G, Deckelbaum RJ. Pregnancy-associated obesity in black women in New York city. Matern Child Health J. 2002;6:37-42. 10. Abrams B, Gunderson E. Epidemiology of ges-
tational weight gain and body weight changes after pregnancy. Epidemiol Rev. 2000;22:261-274. 11. US Department of Health and Human Services. Healthy People 2010: Understanding and Improving Health. 2nd ed. Washington, DC: US Government Printing Office; November 2000. 12. Abbey B, Wiemann CM, Rowe TF, Rickert VI. Inadequate weight gain among pregnant adolescents: Risk factors and relationship to infant birth weight. Am J Obstet Gynecol. 1997;176:12201224. 13. Dewey KG, Loris P, Poirier-Brode K. Weight gain and dietary intake of pregnant teenagers. J Am Diet Assoc. 1985;85:1296-1303. 14. Blankson ML, Cliver SP, Goldenberg RL, Hickey CA. Maternal weight status and term birth weight in first and second adolescent pregnancies. J Adolesc Health. 1992;13:561-569. 15. McAarney ER, Stevens-Simon C. First do no harm, low birth weight and adolescent obesity. Adolesc Obes. 1993;147:983-985. 16. Hediger ML, Schall JI, Scholl TO. Excessive gestational weight gain and chronic disease risk. Am J Human Biol. 1996;8:735-741. 17. Ances IG, Belsky DH, Hediger ML, Belsky DH, Salmon RW. Weight gain during pregnancy in adolescence: Predictive ability of early weight gain. Obstet Gynecol. 1990;75:948-953. 18. Scholl TO, Ances IG, Hediger ML, Schall JI, Smith WK. Gestational weight gain, pregnancy outcome, and postpartum weight retention. Obstet Gynecol. 1995;86:423-427. 19. MacLeod S, Kiely JL. The effects of maternal age and parity on birth weight: A populationbased study in New York city. Int J Gynecol Obstet. 1988;26:11-19. 20. Taffel S. Maternal Weight Gain and the Outcome of Pregnancy, United States, 1980. Hyattsville, MD: National Center for Health Statistics; 1986. Vital and Health Statistics Series 21, No. 44. 21. Ventura SJ, Martin JA, Park M, Menacker F, Hamilton BE. Births: Final Data for 2000. Hyattsville, MD: National Center for Health Statistics; 2002. National Vital Statistics Reports, Vol. 49 No. 1. 22. Suitor CW. Maternal weight gain. A report of an expert work group. Arlington, VA: National Center for Education in Maternal and Child Health; 1997. 23. Hellerstedt WL, Pirie PL, Alexander GR. Adolescent parity and infant mortality, Minnesota, 1980 through 1988. Am J Public Health. 1995;85: 1139-1142. 24. Gortmarker S, Must A, Perrin JM, Sobol AM, Dietz WH. Social and economic consequences of overweight in adolescence and young adulthood. N Engl J Med. 1993;329:1008-1012. 25. Neumark-Sztainer D, Story M, French SA, Hannan PJ, Resnich MD, Blum RW. Psychosocial concerns and health-compromising behaviors among overweight and nonoverweight adolescents. Obes Res. 1997;3:237-249.
Journal of THE AMERICAN DIETETIC ASSOCIATION / 1657
Excessive maternal weight gain patterns in adolescents LAJEANA D. HOWIE, MPH; JENNIFER D. PARKER, PhD; KENNETH C. SCHOENDORF, MD, MPH
ABSTRACT The objective of this study was to examine the correlates of excessive maternal weight gain among adolescent mothers in the United States. Data from the Centers for Disease Control & Prevention 2000 natality file were analyzed to examine weight gain among adolescents (ⱕ19 years) compared with their older counterparts (ⱖ20 years). Using the Institute of Medicine guidelines, we defined excessive weight gain as more than 40 pounds. Our study population was restricted to singleton births, delivered after 36 weeks of gestation, who did not live in California. Maternal weight gain distributions were tabulated by maternal age and other maternal characteristics. Demographic characteristics potentially associated with maternal weight gain were compared for adolescents and older mothers. We further evaluated the role of parity and maternal race on the relationship between excessive weight gain and maternal age. Odds ratios and 95% confidence intervals were estimated using logistic regression. Over 27% of adolescent mothers gained excessive weight during pregnancy, although approximately 18% of their older counterparts gained more than 40 pounds. The association between young maternal age and weight gain was stronger for primiparous women than multiparous women and stronger among non-Hispanic white and non-Hispanic black mothers than Hispanic mothers. Adolescents were more likely to gain excessive weight than their older counterparts in nearly all demographic categories, regardless of parity or race. Adolescents are at high risk of gaining an excessive amount of weight during pregnancy and should be monitored during pregnancy by dietetics professionals. J Am Diet Assoc. 2003;103:1653-1657.
xcessive maternal weight gain has been associated with many pregnancy-related health risks, including labor and delivery complications, maternal anemia, preterm labor, macrosomia, and infant mortality (1-3). In addition, postpartum weight retention, a direct consequence of excessive maternal weight gain, can lead to obesity (2,4,5). Obesity increases a woman’s risk of major health problems, including hypertension, heart
E
disease, diabetes, and some types of cancers (6-9). Obesity affects the health status of many women and is steadily increasing in women of reproductive age (4,5,10). Obesity is a major public health concern, and reducing the proportion of adults who are obese has been listed as one of Healthy People 2010’s objectives (11). Research comparing maternal weight gain differences in adolescents and older
L. D. Howie is a health statistician, J. D. Parker is a health research scientist, and K. C. Schoendorf is chief, Infant and Child Health Studies Branch, Centers for Disease Control and Prevention, National Center for Health Statistics, Hyattsville, MD. Address correspondence to: LaJeana D. Howie, MPH, Centers for Disease Control and Prevention, National Center for Health Statistics, 3311 Toledo Rd, Room #6105, Hyattsville, MD 20782. E-mail: [email protected] Copyright © 2003 by the American Dietetic Association. 0002-8223/03/10312-0011$30.00/0 doi: 10.1016/j.jada.2003.09.040
mothers has shown that adolescents gain more weight during pregnancy than their older counterparts (4,8,12,13). Increased maternal weight gain in adolescents compared with older women has been attributed, in part, to the adolescent body working to meet the needs of its own growth in addition to the needs of the growing fetus (13-15). As a result, some of the increased maternal weight gain in adolescents may be associated with increased birth weights of infants and more favorable pregnancy outcomes (1,16,17). However, there is evidence that adolescent mothers with excessive maternal weight gain have a greater tendency to retain excess weight postpartum (18). Previous studies have found that primiparas, mothers pregnant with their first infant, are more likely to gain an excessive amount of weight during pregnancy than multiparas (19). Because adolescents are primarily primiparous (19), it is unclear how much of the excessive maternal prenatal weight gain observed among adolescents is because of primiparity rather than age. Adolescents who gain an excessive amount of weight during their first pregnancy may retain some of this weight and continue to gain weight with each subsequent pregnancy. Understanding the relative contributions of age and parity on prenatal weight gain may be important for determining how to best prevent obesity among adolescent mothers (19). In addition, studies have shown that a relationship exists between race/ethnicity and maternal weight gain. For example, white mothers are more likely to gain an excessive amount of weight during pregnancy than black mothers (20). Furthermore, studies have also shown that a relationship exists between race/ethnicity and maternal age. For example, white mothers are more likely to have children at a later age than black or Hispanic women (21). However, the importance of race/ethnicity on the relationship between age and maternal weight gain is unknown. The purpose of this study was to examine the correlates of excessive maternal weight gain among adolescent mothers in the United States, using 2000 natality data. Most studies on maternal weight gain in adolescents have relied on clinical populations and are not nationally representative. Although it is known that adolescent mothers gain more weight than their older counterparts, this study provides a recent national per-
Journal of THE AMERICAN DIETETIC ASSOCIATION / 1653
RESEARCH AND PROFESSIONAL BRIEFS
Table 1 Distribution and percent high maternal weight gain (⬎40 lb) of singleton births, by selected maternal characteristics, CDC natality file 2000a Maternal characteristics Maternal age (yr) ⱕ15 16-17 18-19 20-24 25-29 30-34 35-39 40 or older Parity Primipara Multipara Race/ethnicity Non-Hispanic black Hispanic or Latina Non-Hispanic white Other groups Educationc Adequate Inadequate Gestational age (wk) 37 38 39 40 41 42 or more Region Northeast Midwest South West
Study sample
%
% high maternal weight gainb
18,619 89,639 215,089 711,343 764,150 641,426 298,583 57,956
0.7 3.2 7.7 25.4 27.3 22.8 10.7 2.1
28.7 27.8 26.7 21.6 18.6 16.2 14.5 12.8
1,145,042 1,651,763
40.9 59.1
24.9 15.3
415,958 417,744 1,831,322 131,781
14.9 14.9 65.5 4.7
16.1 19.4 20.3 14.6
2,306,677 490,128
82.5 17.5
19.3 19.2
247,822 517,449 773,117 676,693 349,472 232,252
8.9 18.5 27.6 24.2 12.5 8.3
16.5 17.5 18.4 20.2 22.2 22.2
554,363 737,676 1,159,764 345,002
19.8 26.4 41.5 12.3
18.7 19.9 19.2 19.1
a Study population limited to mothers delivering singletons with known maternal weight gain, gestational age, parity, education, race, and age. Births to California residents were excluded. b Associations between percent high weight gain and maternal characteristics are all statistically significant, P⬍.01. c Education is considered adequate for mothers 18 years of age and older who completed high school and for those under 18 years of age if schooling was six or fewer years less than their age.
spective on the pregnancy weight gain of these mothers. METHODS The 2000 US natality file compiled by the Centers for Disease Control and Prevention, National Center for Health Statistics, has information for all birth records from all states and the District of Columbia. Our study population was restricted to singleton births of infants delivered after 36 weeks of gestation. California does not collect information on maternal weight gain; therefore, births to California residents were excluded from this analysis (531,959) (21). Birth records missing information for maternal weight gain (7.2%), gestational age (1.1%), parity (.4%), or education (1.4%) were also excluded. The final study population consisted of 2,796,805 births. Current weight gain guidelines, which differ by prepregnancy body mass index 1654 / December 2003 Volume 103 Number 12
(BMI), were issued by the Institute of Medicine (IOM) in 1990. The guidelines recommend pregnant women of low prepregnancy BMI gain between 28 and 40 pounds, women of normal BMI gain 25 to 35 pounds, and women with a high BMI gain 15 to 25 pounds. Adolescents are encouraged to gain weight at the upper end of the spectrum (5,22). Unfortunately, birth certificates did not collect information on maternal height or prepregnancy weight, preventing the calculation of prepregnancy BMI. Because 40 pounds is the highest amount of weight that anyone should gain during pregnancy, regardless of age or BMI, excessive weight gain was defined as greater than 40 pounds. Maternal weight gain was divided into two categories, 40 pounds or less, and greater than 40 pounds. Maternal age, the focus of our study, was separated into eight categories,
⬍15, 16 to 17, 18 to 19, 20 to 24, 25 to 29, 30 to 34, 35 to 39 and 40 years or older. The adolescents were considered to be 19 years of age or younger, although we examined them in smaller age categories. Factors that are known to be associated with both maternal age and prenatal weight gain in the United States were included in the analysis. Parity was divided into two groups, either first or subsequent birth. Higher parity was not considered separately in our analysis because the focus of the study was on adolescents. To examine weight gain differences by maternal race and ethnicity, we created a composite variable: Hispanic, non-Hispanic black, non-Hispanic white, and other groups. Although we had too few adolescent mothers in the other race groups for stable analysis and this is a heterogeneous group, these mothers were retained for tabulations by other maternal characteristics, but not discussed separately. The standard definitions of education were not appropriate for adolescents, who may have not had the opportunity to finish high school. Therefore, we defined education as either adequate or inadequate for age. All women who were 18 years of age or older and completed high school were considered to have adequate education for their age. Mothers less than 18 years of age were considered to have adequate education if their year of schooling was 6 years less than their age or higher (23). Because our study examines total weight gain, limiting the study to term deliveries reduces, although does not eliminate, the bias from differential length of pregnancy. Gestational age was also included as a potential confounder of the association between maternal age and weight gain because women with longer pregnancies have had more time to gain more weight. Gestational age was defined as the number of weeks from the last menstrual period to delivery. Region was separated into four categories, Northeast, Midwest, South, and West. STATISTICAL ANALYSIS All statistical analysis was performed using the Statistical Analysis Software (SAS 8.2, 1999-2001; SAS Institute Inc., Cary, NC). First, the weight gain distribution was tabulated by maternal age and other maternal characteristics. Second, excessive weight gain among adolescent mothers was retabulated by maternal characteristics. Logistic regression models were used to examine the relationship between maternal age and
RESEARCH AND PROFESSIONAL BRIEFS
Table 2 Percent high maternal weight gain (⬎40 lb) by maternal age and other maternal characteristics, CDC natality file 2000a Maternal characteristics
Race/ethnicity Non-Hispanic black Hispanic or Latina Non-Hispanic white Other groups Parity Primipara Multipara Educationc Adequate Inadequate Gestational age (wk) 37 38 39 40 41 42 or more Region Northeast Midwest South West
Maternal ageb ≤15 y Nⴝ18,619
16-17 y Nⴝ89,639
18-19 y Nⴝ215,089
20ⴙ y Nⴝ2,473,458
26.0 24.7 35.5 29.0
22.7 22.6 33.7 26.9
20.4 22.2 31.2 24.8
15.0 18.6 19.2 13.7
29.1 14.5
29.1 16.2
30.0 16.9
23.5 15.3
28.8 28.6
28.0 27.6
28.0 25.2
18.5 16.4
21.8 26.3 27.0 29.8 34.0 34.2
22.4 23.9 26.6 29.3 32.4 32.1
21.5 23.5 25.4 27.9 30.8 30.6
15.8 16.7 17.5 19.1 20.7 20.5
29.6 31.4 27.3 28.7
27.9 30.3 26.4 28.4
27.2 28.6 25.4 27.3
18.0 18.8 18.1 17.9
a
Study population limited to mothers delivering singletons with known maternal weight gain, gestational age, parity, education, race, and age. Births to California residents were excluded. Associations between percent high weight gain and maternal characteristics are all statistically significant, P⬍.01. c Education is considered adequate for mothers 18 years of age or older who completed high school and for those under 18 years of age if schooling was six or fewer years less than their age or higher. b
excessive weight gain, controlling for the potentially confounding effects of maternal race/ethnicity, education, parity, region, and gestational age. We also observed that the relationship between maternal age and weight gain varied by race/ethnicity and parity. We then fit separate logistic models for non-Hispanic white, non-Hispanic black, and Hispanic mothers by parity to further examine these relationships. RESULTS Adolescents were more likely to gain an excessive amount of weight during pregnancy compared with older women (Table 1). Women having their first birth were considerably more likely to gain excess weight than those having subsequent births. Non-Hispanic white women were more likely to gain an excessive amount of weight during pregnancy compared with all other race/ethnicity categories. The excessive weight gain was similar among mothers with adequate and inadequate education and among regions of the country. As expected, excessive weight gain generally increased with gestational age. Table 2 presents the percentage of mothers with excessive weight gain by
maternal age and other maternal characteristics. Adolescent mothers in the three age groups were more likely than those in the older mothers age group to gain an excessive amount of weight in nearly every category. The relationships between maternal age and excessive weight gain were also generally stronger among the younger adolescents compared with the older adolescents. Table 3 shows the unadjusted and adjusted odds ratios and their corresponding 95% confidence intervals for excessive weight gain. Compared with mothers 25 to 29 years of age, the risk of high maternal weight gain was highest for adolescents 15 years of age or younger. The risk of high maternal weight gain decreased as maternal age increased. When other variables were added to the model, the magnitude of the association between maternal age and excessive weight gain decreased, but the adolescents 15 years of age or younger continued to be more likely to gain an excessive amount of weight during pregnancy. Primiparous women were more likely to gain an excessive amount of weight than multiparous women, although the association between parity and weight
gain decreased after adjustment for other maternal factors. After adjustments, the odds ratio for non-Hispanic black and Hispanic women decreased slightly. The odds ratio for women who have inadequate education decreased, and the odd ratios for gestation and region were similar, after adjustments to the model. Given the seeming differences between age and maternal weight gain by both parity and race/ethnicity, shown in Table 2, we created stratified models to examine whether the association differed by these factors (Table 4). The relationship between maternal age and excessive weight gain was strongest among non-Hispanic white primiparous adolescents after adjusting for the other maternal factors. Among multiparous women, there was little difference in excessive weight gain by age, regardless of race/ ethnicity. DISCUSSION Similar to other studies, we found that adolescents were more likely to gain an excessive amount of weight during pregnancy than their older counterparts (4,8,12,13). Over 27% of adolescents exceeded the absolute IOM weight gain
Journal of THE AMERICAN DIETETIC ASSOCIATION / 1655
RESEARCH AND PROFESSIONAL BRIEFS
Table 3 Unadjusted and adjusted odds ratios (OR) and 95% confidence intervals (CI) for association between high maternal weight gain (⬎40 lb) and maternal characteristics, CDC natality file 2000a
Maternal age (y) ⱕ15 16-17 18-19 20-24 25-29 30-34 35-39 40 or older Race/ethnicity Non-Hispanic black Hispanic or Latina Non-Hispanic white Other groups Parity Primipara Multipara Educationc Adequate Inadequate Gestational age 37 38 39 40 41 42 or more Region Northeast Midwest South West
Unadjusted OR (95% CI)
Adjustedb OR (95% CI)
1.75 (1.70-1.81) 1.29 (1.28-1.30) 1.16 (1.16-1.17) 1.04 (1.04-1.05) Reference 0.96 (0.96-0.97) 0.95 (0.95-0.95) 0.93 (0.93-0.94)
1.44 (1.39-1.49) 1.18 (1.17-1.19) 1.11 (1.11-1.11) 1.04 (1.03-1.04) Reference 0.97 (0.97-0.97) 0.96 (0.96-0.96) 0.94 (0.94-0.95)
0.75 (0.74-0.76) 0.97 (0.96-0.97) Reference 0.87 (0.87-0.88)
0.72 (0.71-0.72) 0.94 (0.94-0.95) Reference 0.87 (0.87-0.88)
1.83 (1.81-1.84) Reference
1.60 (1.59-1.61) Reference
Reference 0.99 (0.98-1.00)
Reference 0.95 (0.94-0.96)
0.87 (0.86-0.88) 0.96 (0.96-0.97) Reference 1.03 (1.03-1.04) 1.05 (1.05-1.06) 1.04 (1.04-1.05)
0.87 (0.86-0.88) 0.97 (0.97-0.98) Reference 1.02 (1.02-1.02) 1.03 (1.03-1.04) 1.03 (1.03-1.03)
0.97 (0.96-0.98) 1.02 (1.02-1.03) Reference 0.99 (0.99-1.00)
1.01 (1.01-1.02) 1.01 (1.01-1.02) Reference 1.01 (1.00-1.01)
a Study population limited to mothers delivering singletons with known maternal weight gain, gestational age, parity, education, race, and age. Births to California residents were excluded. b Adjusted for region, maternal age, parity, education, and gestational age. c Education is considered adequate for mothers 18 years of age and older who completed high school and for those under 18 years of age if year of schooling was six or fewer years less than their age or higher.
guidelines, regardless of BMI. Mothers 15 years of age or younger were the most likely to gain excessive weight during pregnancy. Potential explanations for this finding include the absence of proper prenatal care and nutrition advice during their pregnancy or the beneficial adaptation of nutritional intake or metabolic processes to enable both their own normal growth and that of their fetus. A large part of the overall disparity in excessive weight gain between adolescents and adults is because of differences in parity. Primiparous adolescents were substantially more likely to gain more than 40 pounds than were their adult counterparts. There was a minimal association between maternal age and excessive weight gain among multiparous mothers. Unfortunately, the birth certificate does not include information on maternal weight and height, preventing the 1656 / December 2003 Volume 103 Number 12
calculation of prepregnancy BMI. As a result, many mothers with gains considered high by IOM standards are not included in our high weight gain group. This could also be a compounded problem for a specific adolescent or older mother with two or more pregnancies because she may have higher prepregnancy weights. It has not been documented whether adolescents with excessive weight gain during pregnancy are more likely or less likely to gain an excessive amount of weight in subsequent pregnancies, although our results for multiparous women suggest that they are at decreased risk. There was potential for bias in our study associated with gestational age. It is known that adolescents are most likely to deliver their infants at an early gestational age and that weight gain tends to increase with gestational age. However, adolescents in our study gained more
weight during their pregnancies than their older counterparts regardless of gestational age. Therefore, our findings are most likely conservative, although we adjusted for gestational age in our regression models. Maternal weight gain data were missing for 7.2% of the eligible study population. Although the primary analysis excluded mothers with missing weight gain, given the large percent missing we examined the excluded births more closely. Younger and older mothers, nonHispanic black mothers, mothers from the West, and mothers with inadequate education were more likely to be missing weight gain data. The impact of missing data on our results depends on which mothers are missing data, which we know, and the weight gain patterns for these mothers, which we do not know. Because there was a relatively high percentage of weight gain data missing for mothers under 15 years of age, who are at highest risk of excessive weight gain, our findings for adolescents as a group might be conservative. However, the mothers under 15 years of age make up a small percentage of adolescent mothers. Despite our limitations, our study showed that adolescents gain an excessive amount of weight during pregnancy compared with older women, as noted in other articles (4,8,12,13). Although higher weight gains during adolescent pregnancy may be associated with better birth outcomes, they are also associated with subsequent health risks for the mother (17). Excessive weight gain during pregnancy can cause postpartum obesity, which can result in severe medical and psychosocial consequences, particularly for adolescent women (24,25). The potential beneficial and deleterious effects of excessive weight gain during pregnancy on maternal and infant outcomes and its contribution to postpartum obesity among adolescent mothers is an area that merits more in-depth study.
APPLICATIONS During prenatal care, dietitians should explain to pregnant adolescents the problems for the mother and infant that are associated with gaining an excessive amount of weight during pregnancy. ■ Adolescents require special attention from dietitians during their pregnancies because they tend to gain an excessive ■
RESEARCH AND PROFESSIONAL BRIEFS
Table 4 Adjusted odds ratios (OR) and 95% confidence intervals (CI) for association between high maternal weight gain (⬎40 lb) and age by parity and race/ethnicity, CDC natality file 2000a Race/ethnicity
Non-Hispanic white ⱕ15 16-17 18-19 20-24 25-29 30-34 35-39 40⫹ Non-Hispanic black ⱕ15 16-17 18-19 20-24 25-29 30-34 35-39 40⫹ Hispanic or Latina ⱕ15 16-17 18-19 20-24 25-29 30-34 35-39 40⫹
Parity Primipara adjustedb OR (95% CI)
Multipara adjustedb OR (95% CI)
1.75 (1.66-1.85) 1.29 (1.28-1.31) 1.17 (1.17-1.18) 1.07 (1.07-1.07) Reference 0.96 (0.95-0.96) 0.94 (0.94-0.94) 0.92 (0.92-0.93)
0.94 (0.52-1.71) 1.09 (1.04-1.14) 1.05 (1.04-1.06) 1.01 (1.01-1.02) Reference 0.97 (0.97-0.97) 0.96 (0.96-0.96) 0.95 (0.94-0.95)
1.42 (1.32-1.52) 1.11 (1.09-1.14) 1.05 (1.04-1.07) 1.01 (1.00-1.02) Reference 0.97 (0.96-0.98) 0.96 (0.95-0.98) 0.92 (90.89-0.94)
1.03 (0.66-1.60) 1.01 (0.96-1.07) 1.01 (0.99-1.03) 1.00 (0.99-1.01) Reference 0.99 (0.98-1.00) 0.98 (0.97-0.99) 0.98 (0.97-0.99)
1.12 (1.06-1.19) 1.02 (1.00-1.04) 1.04 (1.02-1.04) 1.03 (1.02-1.04) Reference 0.96 (0.95-0.97) 0.94 (0.93-0.95) 0.91 (0.89-0.93)
0.85 (0.59-1.22) 0.96 (0.91-1.00) 0.97 (0.96-0.99) 0.99 (0.99-1.00) Reference 0.99 (0.99-0.98) 0.98 (0.97-0.98) 0.96 (0.95-0.97)
a Study population limited to mothers delivering singletons with known maternal weight gain, gestational age, parity, education, race, and age. Births to California residents were excluded. b Models stratified by parity adjusted for race/ethnicity and maternal age by parity.
amount of weight during their pregnancies. References 1. Christine SA, Furey CH, Miller LK, Salmon RW, Vasilenko P. Weight gain during adolescent pregnancy. J Adolesc Health Care. 1988;9:286-290. 2. Scholl TO, Hediger M. Weight gain, nutrition, and pregnancy outcome; findings from the Camden study of teenage and minority gravidas. Semin Perinatol. 1995;19:171-180. 3. Giddens JB, Gup S, Krug SK, Tsang R, Miodovnik M, Prada JA. Pregnant adolescent and adult women have similarly low intakes of selected nutrients. J Am Diet Assoc. 2000;100:1334-1340. 4. Green GW, Karp RJ, Scholl TO, SmiciklasWright H. Postpartum weight change: How much
of the weight gained in pregnancy will be lost after delivery? Obstet Gynecol. 1998;71:701-707. 5. Cogswell ME, Scanlon KS, Schieve LA. Trends in pregnancy weight gain within and outside ranges recommended by the institute of medicine in a WIC population. Matern Child Health J. 1998; 2:111-115. 6. Haggerty M. Obesity. Gale Encyclopedia of Medicine. 1999;1:2075-2082. 7. Hediger ML, Salmon RW, School TO. Early weight gain in pregnant adolescents and fetal outcome. Am J Human Biol. 1989;1:665-672. 8. McAnarney ER, Segel JS. Adolescent pregnancy and subsequent obesity in African-American girls. J Adolesc Health. 1994;15:491-494. 9. Lederman SA, Alfasi G, Deckelbaum RJ. Pregnancy-associated obesity in black women in New York city. Matern Child Health J. 2002;6:37-42. 10. Abrams B, Gunderson E. Epidemiology of ges-
tational weight gain and body weight changes after pregnancy. Epidemiol Rev. 2000;22:261-274. 11. US Department of Health and Human Services. Healthy People 2010: Understanding and Improving Health. 2nd ed. Washington, DC: US Government Printing Office; November 2000. 12. Abbey B, Wiemann CM, Rowe TF, Rickert VI. Inadequate weight gain among pregnant adolescents: Risk factors and relationship to infant birth weight. Am J Obstet Gynecol. 1997;176:12201224. 13. Dewey KG, Loris P, Poirier-Brode K. Weight gain and dietary intake of pregnant teenagers. J Am Diet Assoc. 1985;85:1296-1303. 14. Blankson ML, Cliver SP, Goldenberg RL, Hickey CA. Maternal weight status and term birth weight in first and second adolescent pregnancies. J Adolesc Health. 1992;13:561-569. 15. McAarney ER, Stevens-Simon C. First do no harm, low birth weight and adolescent obesity. Adolesc Obes. 1993;147:983-985. 16. Hediger ML, Schall JI, Scholl TO. Excessive gestational weight gain and chronic disease risk. Am J Human Biol. 1996;8:735-741. 17. Ances IG, Belsky DH, Hediger ML, Belsky DH, Salmon RW. Weight gain during pregnancy in adolescence: Predictive ability of early weight gain. Obstet Gynecol. 1990;75:948-953. 18. Scholl TO, Ances IG, Hediger ML, Schall JI, Smith WK. Gestational weight gain, pregnancy outcome, and postpartum weight retention. Obstet Gynecol. 1995;86:423-427. 19. MacLeod S, Kiely JL. The effects of maternal age and parity on birth weight: A populationbased study in New York city. Int J Gynecol Obstet. 1988;26:11-19. 20. Taffel S. Maternal Weight Gain and the Outcome of Pregnancy, United States, 1980. Hyattsville, MD: National Center for Health Statistics; 1986. Vital and Health Statistics Series 21, No. 44. 21. Ventura SJ, Martin JA, Park M, Menacker F, Hamilton BE. Births: Final Data for 2000. Hyattsville, MD: National Center for Health Statistics; 2002. National Vital Statistics Reports, Vol. 49 No. 1. 22. Suitor CW. Maternal weight gain. A report of an expert work group. Arlington, VA: National Center for Education in Maternal and Child Health; 1997. 23. Hellerstedt WL, Pirie PL, Alexander GR. Adolescent parity and infant mortality, Minnesota, 1980 through 1988. Am J Public Health. 1995;85: 1139-1142. 24. Gortmarker S, Must A, Perrin JM, Sobol AM, Dietz WH. Social and economic consequences of overweight in adolescence and young adulthood. N Engl J Med. 1993;329:1008-1012. 25. Neumark-Sztainer D, Story M, French SA, Hannan PJ, Resnich MD, Blum RW. Psychosocial concerns and health-compromising behaviors among overweight and nonoverweight adolescents. Obes Res. 1997;3:237-249.
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