Maternal weight, weight gain during pregnancy and pregnancy outcome.

OBJECTIVE: To evaluate the effects of abnormal maternal weight or weight gain on pregnancy outcome.
METHOD: Records for 191 mothers with abnormal prepregnancy weight (> or = 20%) above, or under, ideal body weight for height) or weight gain > or = 20 kg, or < or = 5 kg during pregnancy were reviewed. The control group consisted of 166 mothers with normal prepregnancy weight and normal weight gain during pregnancy. Data on mothers and their infants were analyzed by one-way analysis of variance.
RESULTS: Obese women and mothers with excessive weight gain during pregnancy had an increased incidence of induced labor (P < or = 0.05) and tendency for emergency cesarean sections during the delivery. Obese women had more large-for-date babies than controls (P < or = 0.05). Weight gain < or = 5 kg during pregnancy was most common in slightly obese women and did not carry any special obstetric or neonatal risk. Underweight women had a significant risk for delivering a small-for-data baby.
CONCLUSION: Obese women and women with excessive weight gain during pregnancy need special follow-up and counseling during pregnancy and delivery. Underweight women may need prepregnancy nutritional counseling to guarantee normal fetal growth. In developed countries suboptimal weight gain (< or = 5 kg) during pregnancy seems not to need any medical intervention.