Abstract：Objective To investigate the weight gain in the second and third trimesters of pregnancy and its related factors among urban women so as to provide a scientific basis for rational control of body weight in pregnant women. Methods Historical cohort study was used to survey 1,176 pregnant women who had antenatal examination records and underwent prenatal check-up and delivery in a third-grade class-A hospital in Beijing in 2015. Medical record inquiry method was employed to investigate the data about the pregnant women’s general information and their body weight at the 6th-8th, 16th, 20th, 24th, 28th, 32nd and 36th weeks of gestation and on parturition day. We explored the trend of weight gain during pregnancy and its related influencing factors through analyzing the pregnant women’s gestational weight gain and weekly weight gain. Results The total gestational weight gain of the surveyed pregnant women was (13.8±4.3) kg averagely. The weekly weight gain decreased from the 24th week of pregnancy, and it was found to be higher in the second trimester than in the third one. The gestational weight gain was closely correlated with body mass index (BMI) at the 6th-8th weeks of pregnancy. The total gestational weight gain ((11.8± 4.6) kg) and weekly weight gain in the overweight/obesity group were significantly lower than those in the low body weight group ((14.1±3.3) kg) and the normal body weight group ((13.9±3.9) kg), showing statistically significant differences (both P<0.05), but the changes in the weekly weight gain in the overweight/obesity group were generally stable. According to the 2009 Institute of Medicine Guidelines, 41.2% of the pregnant women had proper weight gain, 23.3% insufficient weight gain and 34.5% excessive weight gain. The proportion of insufficient gestational weight gain was higher in the low body weight group (31.7%), but the proportion of excessive gestational weight gain was higher in the overweight/obesity group (58.6%). The gestational weight gain was lower in pregnant women aged ≥35 years than in ones aged < 35 years, but no statistically significant difference was found in the changing trend (P>0.05). The weekly weight gain of different age groups showed a decreasing tendency and statistically significant differences (P<0.001), of which the changes in the weekly weight gain of the age group of ≥35 years were stable (P>0.05). The gestational weight gain was lower in multiparas than in primiparas (P<0.05), without a statistically significant difference (P>0.05). Multivariate analysis showed that weight gain during pregnancy was correlated with maternal age, BMI at the 6th-8th weeks of pregnancy and pregnancy week at delivery, and the equation was Y=9.027-0.114X1-0.258X2+0.352X4. Conclusion The weight gain during pregnancy of the pregnant women is found to be higher in the second trimester in comparison with the third one, and the total gestational weight gain is closely associated with BMI at the 6th-8th weeks of pregnancy.
2019, Vol. 26 
