Maternal gestational weight gain and offspring weight in adolescence

Abstract

Objective: To study associations of maternal gestational weight gain with offspring weight status in adolescence.

Methods: We surveyed 11,994 adolescents aged 9-14 years enrolled in the Growing Up Today Study cohort and their mothers, members of the Nurses' Health Study II. We used multivariable linear and logistic regression to study associations of gestational weight gain with offspring adiposity.

Results: Mean (standard deviation) gestational weight gain was 31.5 (11.2) pounds, and offspring body mass index (BMI) z score (BMI standardized for age and sex) was 0.15 (1.0) units; 6.5% of adolescents were obese (BMI 95th percentile or higher) (BMI is calculated as weight [kg]/[height (m)]2). Gestational gain was linearly associated with adolescent adiposity: compared with 20-24 pounds, gain less than 10 pounds was associated with child BMI z score 0.25 units lower (95% confidence interval [CI] -0.47 to -0.04), and gain 45 pounds or more with BMI z score 0.18 units higher (95% CI 0.11-0.25). Compared with women with adequate gain according to 1990 Institute of Medicine guidelines, women with excessive gain had children with higher BMI z scores (0.14 units, 95% CI 0.09-0.18) and risk of obesity (odds ratio 1.42, 95% CI 1.19-1.70). The predicted prevalence of term low birth weight declined modestly across the range of gain (2% for gain less than 10 pounds, 1% for gain 45 pounds or more), whereas term high birth weight increased dramatically with higher gain (10% for gain less than 10 pounds, 35% for gain of 45 pounds or more).

Conclusion: Gestational weight gain is directly associated with BMI and risk of obesity in adolescence. Revised gestational weight-gain guidelines should account for influences on child weight.

Level of evidence: II.

Figure 1

Associations of maternal gestational weight gain with child BMI z-score, with and without adjustment for maternal pre-pregnancy BMI. All estimates are adjusted for maternal age, race/ethnicity, and marital status; household income and paternal education; and child sex, gestation length, age and Tanner stage at outcome assessment. BMI: body mass index.

Figure 2

Predicted probabilities of birth weight > 4000g, and birth weight < 2500g among term births, according to maternal gestational weight gain. We predicted probabilities for the typical Growing Up Ttoday Study mother: white, never smoker, husband with a college degree, household income over $44,500, pre-pregnancy BMI 22.2 kg/m², age at delivery 29.4 years, and gestation length greater than or equal to 40 weeks. BMI: body mass index.