Adverse Neonatal Outcomes in Overweight and Obese Adolescents Compared with Normal Weight Adolescents and Low Risk Adults.

STUDY OBJECTIVE: To evaluate the association between maternal body mass index and neonatal outcomes in adolescents and to compare neonatal outcomes between overweight and obese adolescents and obstetric low-risk adult women.

DESIGN: Retrospective cohort study using data from the Swedish Medical Birth Register.

SETTING: Sweden.

PARTICIPANTS: All 31,386 primiparous adolescents younger than 20 years of age and 178,844 "standard" women, defined as normal weight, obstetric low-risk adult women who delivered between 1992 and 2013. The adolescents were categorized according to weight and height in early pregnancy into body mass index groups according to the World Health Organization classification. Logistic regression models were used.

INTERVENTIONS AND MAIN OUTCOME MEASURES: Neonatal outcomes in relation to maternal body mass index groups.

RESULTS: In the adolescents, 6109/31,386 (19.5%) and 2287/31,386 (7.3%) were overweight and obese, respectively. Compared with normal weight adolescents, overweight adolescents had a lower risk of having small for gestational age neonates, and higher risks for having neonates with macrosomia, and being large for gestational age and with Apgar score less than 7 at 5 minutes. The obese adolescents had increased risk for having neonates being large for gestational age (3.8% vs 1.3%; adjusted odds ratio [aOR], 2.97 [95% confidence interval (CI), 2.30-3.84]), with macrosomia (>4500 g) (4.6% vs 1.4%; aOR, 2.95 [95% CI, 2.33-3.73]), and with Apgar score less than 7 at 5 minutes (2.2% vs 1.1%; aOR, 1.98 [95% CI, 1.43-2.76]) than normal weight adolescents. Compared with the standard women, overweight and obese adolescents had overall more adverse neonatal outcomes.

CONCLUSION: Overweight and obese adolescents had predominantly increased risks for adverse neonatal outcomes compared with normal weight adolescents and standard women.