HealthDay News — Very low or very high weight gains during twin pregnancies are associated with adverse birth outcomes, according to a study published online Oct. 8 in Obstetrics & Gynecology.
Lisa M. Bodnar, PhD, RD, from University of Pittsburgh, and colleagues used data from Pennsylvania-linked infant birth and death records (2003 to 2013) to identify 54,836 twins born alive before 39 weeks of gestation. The associations between gestational weight gain in twin pregnancies and small-for-gestational-age (SGA) and large-for-gestational-age (LGA) birth, preterm birth before 32 weeks of gestation, cesarean delivery, and infant death were evaluated.
The researchers found that the gestational weight gain z score was negatively associated with SGA and positively associated with LGA and cesarean delivery in all prepregnancy body mass groups. In nonobese women, the relation between weight gain and preterm birth was U-shaped. There was an increased risk for infant death for very low weight gain among normal-weight women and for high weight gain among women without obesity. This excess risk was seen for weight gains at 37 weeks of gestation of <14 kg or >27 kg in underweight or normal-weight women, <11 kg or >28 kg in overweight women, and <6.4 kg or >26 kg in women with obesity.
“If the associations we observed are even partially reflective of causality, targeted modification of pregnancy weight gain in women carrying twins might improve pregnancy outcomes,” the authors write.