[Optimal maternal weight gain in twin and triplet pregnancy]

Our purpose was to evaluate the association between maternal weight gain patterns and pregravid body mass index (BMI), toxemia of pregnancy, birthweight, intrartum asphyxia, preterm rupture of membrane, mode of delivery and handicaps, and to make specific recommendations for maternal weight gain in twin and triplet pregnancy. The subjects were 1,436 mothers of twins and 227 mothers of triplets aged from 20 to 34. The following results were obtained. 1) In twin pregnancies, maternal weight gain was significantly lower in overweight women than in under- and normal-weight women. In triplet pregnancies, there was no significant difference in maternal weight gain by BMI. However, gestational week at delivery and birthweight was significantly lower in underweight women than in the normal weight women. The number of babies weighing under 1,500 g was significantly higher in underweight women than in the normal weight women. 2) In twin pregnancies, the risk of toxemia of pregnancy, baby weighting under 1,500 g, intrapartum asphyxia and preterm rupture of membrane was significantly associated with maternal weight gain. Moreover, in triplet pregnancies, toxemia of pregnancy and baby weighing under 1,500 g was significantly associated with maternal weight gain. 3) In twin pregnancies, the mean maternal weight gain in mothers without toxemia of pregnancy, and with baby weighing at least 1,500 g, was 6.2 kg at 36-37 weeks of delivery in overweight women, 12.0 kg at 37 weeks in normal women, and 12.4 kg at 36-37 weeks in the underweight women. The approximate birthweight of twins in those mothers was from 2,300 to 2,500 g. Moreover, in triplet pregnancies, the mean maternal weight gain in mothers without toxemia of pregnancy, and with baby weighing at least 1,500 g, was 12.2 kg at 35 weeks of delivery in normal weight women and 11.8 kg at 34-35 weeks in underweight women. The approximate birthweight of triplets in those mothers was from 1,800 to 2,100 g.