title: The Effect of Adequate Gestational Weight Gain among Adolescents Relative to Adults of Equivalent Body Mass Index and the Risk of Preterm Birth, Cesarean Delivery, and Low Birth Weight.
abstract: OBJECTIVE
  To determine whether similar odds of cesarean delivery (C/S), preterm birth (PTB), and low birth weight (LBW) are observed among adolescents compared with body mass index (BMI)-equivalent adults in cases of adequate gestational weight gain.
  
  
  METHODS
  We conducted a retrospective, population-based, cohort study using the Center for Disease Control and Prevention's birth data files from the United States for 2012. We selected from the cohort all singleton, cephalic pregnancies and stratified them according to maternal age, prepregnancy BMI, and gestational weight gain following the 2009 Institute of Medicine (IOM) recommendations. The effect of adequate gestational weight gain among adolescents relative to adults of equivalent BMI on the risk of C/S, PTB, and LBW was estimated using logistic regression analysis, adjusting for relevant confounders.
  
  
  RESULTS
  We analyzed a total of 3,960,796 births, of which 1,036,646 (26.1%) met the inclusion criteria. In adolescents and adults, likelihood of achieving ideal gestational weight gain decreased with greater prepregnancy BMI. Relative to adults, the overall odds of C/S in all adolescents were (adjusted odds ratio [95% confidence interval]) 0.61 (0.58 to 0.63). When comparing equivalent BMI categories, these odds were unchanged (P < .0001). The overall adjusted odds ratio of LBW was 1.15 (1.13 to 1.16). These odds were significantly higher when BMI stratification took place, decreasing with advancing BMI categories, from 1.23 (1.14 to 1.33) among the underweight, to nonsignificant differences in the obese classes (P < .05). Finally, when including only those achieving ideal weight gain, the overall odds of premature delivery (1.17 [1.14 to 1.20]) were higher among nonobese adolescents, while they were not found among the obese.
  
  
  CONCLUSIONS
  When ideal gestational weight gain is attained, only nonobese adolescents exhibit a greater risk of LBW and preterm birth relative to adults of similar BMI, whereas the risk of C/S remains lower for all adolescents, independent of BMI. This information may be useful in the counseling of adolescent pregnancies.
authors.affiliation: Faculty of Medicine, University of Montreal, Quebec, Canada.
authors.forename: Michele
authors.initials: M
authors.lastname: Houde
authors.affiliation: Department of Obstetrics and Gynecology, University of Montreal, Quebec, Canada; ART-PGD Center, CHU Sainte-Justine, Montreal, Quebec, Canada.
authors.forename: Elias M
authors.initials: EM
authors.lastname: Dahdouh
authors.affiliation: Department of Obstetrics and Gynecology, University of Montreal, Quebec, Canada.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Mongrain
authors.affiliation: Department of Obstetrics and Gynecology, University of Montreal, Quebec, Canada; Division of Pediatric and Adolescent Gynecology, CHU Sainte-Justine, Montreal, Quebec, Canada.
authors.forename: Elise
authors.initials: E
authors.lastname: Dubuc
authors.affiliation: Department of Obstetrics and Gynecology, University of Montreal, Quebec, Canada; Division of Pediatric and Adolescent Gynecology, CHU Sainte-Justine, Montreal, Quebec, Canada.
authors.forename: Diane
authors.initials: D
authors.lastname: Francoeur
authors.affiliation: Department of Obstetrics and Gynecology, University of Montreal, Quebec, Canada. Electronic address: jacques.balayla@umontreal.ca.
authors.forename: Jacques
authors.initials: J
authors.lastname: Balayla
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D002585:Cesarean Section / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D015969:National Academies of Science, Engineering, and Medicine, U.S., Health and Medicine Division; D009765:Obesity; D016017:Odds Ratio; D011247:Pregnancy; D011253:Pregnancy in Adolescence / Q000502:physiology*; D047928:Premature Birth / Q000453:epidemiology* / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D013851:Thinness; D014481:United States; D015430:Weight Gain
keywords: Adolescent obesity; Adolescents; Gestational weight gain; Pregnancy outcomes; Prepregnancy BMI