Maternal weight gain during the first half of pregnancy and offspring obesity at 16 years: a prospective cohort study

Objective To assess the association between maternal gestational weight gain (GWG) during the first 20 weeks of gestation and overweight/ obesity and abdominal obesity of offspring at the age of 16 years. Design A prospective cohort study. Setting The two northernmost provinces of Finland. Population Mothers and their adolescent offspring born from singleton pregnancies (3265 boys; 3372 girls) in the Northern Finland Birth Cohort 1986. Methods Maternal weight at 20 weeks of gestation was measured in municipal maternity clinics. Maternal GWG was based on the difference between the measured weight and self-reported prepregnancy weight, and was classified into quartiles. Offspring weight, height and waist circumference were measured by study nurses during a clinical examination. Logistic regression analyses [ with and without adjustment for maternal pre-pregnancy body mass index (BMI), glucose metabolism, education level, haemoglobin, smoking status, parity, and gender of offspring] were performed. Main outcome measure Offspring overweight/ obesity, based on BMI and abdominal obesity at 16 years. Results The highest quartile of maternal weight gain (> 7.0 kg during the first 20 weeks of gestation) was independently associated with BMI-based overweight/ obesity and abdominal obesity in the 16-year-old offspring (OR 1.46, 95% CI 1.16-1.83, and OR 1.37, 95% CI 1.10-1.72, respectively). Among all covariates, maternal pregravid obesity showed the highest odds for both overweight/ obesity and abdominal obesity (OR 4.57, 95% CI 3.18-6.57, and OR 4.43, 95% CI 3.10-6.34, respectively). Conclusions Maternal overnutrition during the first half of gestation predicts offspring overweight/ obesity and abdominal obesity in adolescence, yet a high pregravid BMI appears to be a more important determinant of both outcomes.