Maternal body weight and relation to birth weight.

Area of Science:

• Obstetrics and Gynecology
• Maternal Health
• Neonatal Outcomes

Background:

• Maternal pre-pregnancy weight and gestational weight gain are crucial factors influencing fetal growth and birth outcomes.
• Understanding these relationships is vital for optimizing prenatal care and addressing potential complications associated with both underweight and overweight pregnancies.

Purpose of the Study:

• To investigate the association between maternal initial body weight, weight gain during pregnancy, and infant birth weight.
• To determine if elevated maternal body mass index (BMI) affects the relationship between maternal weight gain and birth weight.
• To assess the impact of maternal weight on cesarean section rates.

Main Methods:

• Analysis of data from 2,295 subjects in The Stockholm Pregnancy and Weight Development Study.
• Statistical examination of relationships between initial maternal body weight, total weight increase during pregnancy, and birth weight.
• Comparison of birth weight trends in women with different initial BMI categories.

Main Results:

• Total maternal weight increase was the primary predictor of birth weight, followed by initial maternal body weight.
• In women with an initial BMI > 24 kg/m², birth weight did not significantly increase with further maternal weight gain.
• Cesarean section frequency (12% overall) was not significantly associated with maternal body weight.

Conclusions:

• Birth weight is positively correlated with maternal weight gain, but this effect plateaus at higher maternal pre-pregnancy weights (BMI > 24 kg/m²).
• Maternal weight gain is beneficial for fetal growth up to the upper limit of normal maternal body weight.
• Current maternal weight influences birth weight, but excessive maternal weight may attenuate the positive impact of further weight gain on fetal growth.