Pre-Pregnancy Maternal BMI Impacts Baby's Birth Weight
Both pre-pregnant BMI and weight gain during pregnancy influence birth weight
FRIDAY, Dec. 16 (HealthDay News) -- Birth weight is influenced by both pre-pregnancy weight and weight gain during pregnancy, according to a study published online Nov. 14 in Acta Obstetricia et Gynecologica Scandinavica.
Unni Mette Stamnes Koepp, M.D., from the Soerlandet Hospital HF in Kristiansand, Norway, and colleagues investigated the correlation between maternal pre-pregnant body mass index (BMI) and maternal weight change during pregnancy and infant birth weight. A total of 58,383 women, at 17 to 18 weeks of gestation, were enrolled from 2000 to 2007. Exposure data from two questionnaires (during pregnancy) and birth weight data were analyzed.
The investigators found that the mean pre-pregnancy BMI was 24 kg/m², the mean maternal weight change in the first 30 weeks of pregnancy was 9.3 kg, and the mean birth weight was 3,675 grams. After adjusting for potential confounders, offspring birth weight increased with increasing maternal pre-pregnant BMI. In addition, increasing maternal weight gain during pregnancy, in all six categories of pre-pregnancy BMI, was associated with increasing infant birth weight. The highest offspring birth weight was seen for women with the highest level of education.
"Offspring birth weight increased with both increasing maternal pre-pregnant BMI and maternal weight gain during pregnancy in all six categories of maternal pre-pregnancy BMI," the authors write.