To study weight gain characteristics of gestational diabetes mellitus (GDM) and normal pregnant women during perinatal period.

From March 2013 to April 2014, a total of 719 cases of pregnant women who took prenatal check-up as out-patient in department of nutrition or department of obstetrics, and carried out the follow-up in Sichuan Provincial Hospital for Women and Children, West China Second University Hospital of Sichuan University, and Chengdu Women and Children′s Central Hospital were selected as research subjects. The data were built on the basis of 1-year-long longitudinal study on 719 cases of pregnant women, among which 124 cases were GDM (divided into GDM group) and 595 were normal pregnant women (divided into control group). The observations were focused on the weight gains among these two groups of pregnant women in varied ages and pre-pregnancy body mass index (BMI).

In the second, third trimester and throughout whole pregnancy of GDM group, weight gains were lower than those of control group, which were (8.6±3.1) kg vs (9.5±3.0) kg, (4.5±3.0) kg vs (6.4±2.4) kg, and (14.3±3.0) kg vs (16.6±4.5) kg, respectively, and all the differences were statistically significant (t=2.910, P=0.004; t=7.470, P<0.001; t=5.340, P<0.001). In the first trimester pregnancy of GDM group, weight gain was higher than that in control group, which was (1.25±2.23) kg vs (0.74±2.51) kg, and there was significant difference between two groups (t=-2.101, P=0.036). In GDM group, BMI value during pre-pregnancy of pregnancy women whose ages ≥35-year-old was higher than that of ages <35-year-old, while the weight gains during the second and throughout whole pregnancy of pregnant women whose ages≥35-year-old were lower than those of ages<35-year-old and all the differences were statistically significant (t=-2.212, P=0.029; t=2.052, P=0.042; t=2.081, P=0.040). Among ages ≥35-year-old pregnant women, whose BMI value in GDM group was higher than that in control group, but weight gain was lower than that in control group, there were significant differences between two groups (t=-2.715, P=0.009; t=2.732, P=0.008). At postpartum 3 d and 42 d in GDM group, the body weights among pregnancy women with BMI value <18.5 kg/m^2, ≥18.5-24.0 kg/m^2, and BMI≥24.0 kg/m^2, there were significant differences (F=30.357, 24.378; P<0.001), and their body weights increased along with the increasing of their pre-pregnancy BMI values.

It is suggested to take recommended perinatal weight standard as a regular index for GDM. To scientifically prevent and treat GDM, especially the elderly and overweight pre-pregnancy BMI pregnant women.