Application of Japanese guidelines for gestational weight gain to multiple pregnancy outcomes and its optimal range in 101,336 Japanese women

This study was performed to investigate whether the Japanese guidelines for gestational weight gain (GWG) can be used to determine the risks of multiple pregnancy outcomes and estimate optimal GWG in 101,336 women with singleton pregnancies in 2013. Multivariable logistic regression analyses indicated that the risks associated with low birth weight, small for gestational age, and preterm birth increased significantly with weight gain below the Japanese guidelines, and the risks of macrosomia and large for gestational age increased with weight gain above the guidelines regardless of Asian-specific pre-pregnancy body mass index (BMI). The GWG cutoff points estimated from the adjusted area under the receiver operating characteristics curve >0.6 corresponded to 10-13.8 kg in underweight women with pre-pregnancy BMI < 18.5 kg/m(2); 10-13.7 kg in normal weight women with pre-pregnancy BMI 18.5-22.9 kg/m(2); 8.5-11.4 kg in overweight women with pre-pregnancy BMI 23-24.9 kg/m(2), 5-13.3 kg in obese women with pre-pregnancy BMI 25-29.9 kg/m(2); and 4.7 kg in obese women with pre-pregnancy BMI >= 30 kg/m(2). The optimal GWG ranges proposed by the present study are slightly higher than those recommended by the current Japanese guidelines.