Objective To analyze the influence of the body mass gain of twin pregnancies at different stages of pregnancy on the pregnancy outcome.

Methods A total of 546 cases of twin pregnancy pregnant women were selected as the research subject, and the clinical data of pregnant women were retrospectively analyzed. The body mass gain of pregnant women with different body mass before pregnancy was compared during pregnancy, and the correlation between the body mass gain of pregnant women at different stages of pregnancy, pregnancy complications and delivery outcomes was analyzed by logistic regression analysis.

Results The body mass gain of 546 pregnant women in the first and second trimesters was (0.41±0.17) kg/week, in the third trimester was (0.68±0.35) kg/week, and in the whole pregnancy was (0.47±0.16) kg/week. With the increase of pre-pregnancy weight, the incidence of gestational diabetes mellitus in pregnant women showed an increasing trend (P < 0.01). The growth rate of pre-pregnancy body weight in supernormal group was lower than that in low body weight and normal group (P < 0.01). The vaginal delivery rate of pregnant women in the low pre-pregnancy weight group was higher than that in the normal and supernormal groups (P < 0.05). Multivariate logistic regression analysis showed that rapid growth of body mass during pregnancy was a protective factor for adverse outcomes of delivery (premature birth and low birth weight) (P < 0.01), and rapid body mass gain was a risk factor for pregnancy complications (premature rupture of membranes and hypertension) (P < 0.05).

Conclusions The body mass gain of twin pregnancy pregnant women in different stages of pregnancy is closely related to the maternal pregnancy outcome.By monitoring the maternal body mass gain during pregnancy, the effective evaluation of maternal pregnancy outcome can be achieved, which is of great significance to ensure the safety of maternal and infant pregnancy.