[The effect of exposure to prenatal life events and social support levels on low birth weight in offspring: a prospective cohort study].

Objective: To analyze the effects of exposure to life events and social support levels during different stages of pregnancy on low birth weight in offspring. Methods: From 2021 to 2023, pregnant women in early pregnancy who were registered with health cards in Linping District, Hangzhou City, were recruited and followed up. The Life Events Scale for Pregnant Women (LESPW) and Social Support Rating Scale (SSRS) were used to evaluate the exposure to life events and social support levels of pregnant women in early, middle and late pregnancy, respectively. A generalized linear model was used to analyze the impact and critical period of exposure to prenatal life events and social support levels on the risk of low birth weight in offspring. Results: A total of 3 663 pregnant women with ages M (Q₁, Q₃) of 29.18 (26.59, 32.21) years were included in this study. 116 cases (3.17%) of infants with low birth weight were delivered. Generalized linear model analysis showed no correlation between the level of social support in early, middle and late pregnancy and low birth weight in offspring (all P>0.05). The risk of low birth weight in offspring of pregnant women with high exposure to early pregnancy life events was 1.78 times higher than that of the low exposure group (RR=1.78, 95%CI: 1.13-2.73, P=0.010), and there was no association in the middle and late stages of pregnancy (both P>0.05). Pregnant women with high exposure to early life events and low levels of social support had a 2.08-fold higher risk of low birth weight in their offspring compared to the low exposure group (RR=2.08, 95%CI: 1.17-6.78, P=0.010), while this situation was not associated with high social support stratification. Conclusion: Exposure to life events during pregnancy has an early window effect on birth weight. Increased exposure to life events during early pregnancy is associated with a higher risk of low birth weight in offspring. This association is more pronounced in pregnant women with low social support.