OBJECTIVETo explore the influence of occupational stress and negative life events on low birth weight (LBW).

METHODS1:1 matched case-control study was employed, in which 438 singleton LBW infants with birth weight less than 2500 g (their pregnancy term being 28 to 42 weeks) served as case group while 438 with singleton term normal birth weight served as control group matched by sex, delivery time and hospital. All of their mothers were inquired by well trained investigators about their socio-demographic characteristics, occupational stress, and negative life events occurring in different pregnancy term. After controlling for mother's age, occupation, education level and family income, conditional logistic regression was employed to asses the influence of occupational stress and negative life events on LBW.

RESULTSCompared with those with low technical skill utilization and low job decision, mothers with high technical skill utilization (OR=0.62; 95% CI=0.43 approximately 0.91) and high job decision (OR=0.67; 95% CI=0.46 approximately 0.97) significantly decreased the risk of laboring LBW. Compared with those not exposed to negative life events, mothers with negative life event score being=3 in the middle three months of pregnancy (OR=18.85; 95% CI=1.58 approximately 225.02), with negative life event score being 1 in the later three months of pregnancy (OR=2.67; 95% CI=1.14 approximately 6.28), with negative life event score being 2 (OR=2.80; 95% CI=1.04 approximately 7.52) and=3 in the whole time of pregnancy (OR=2.94; 95% CI=1.22 approximately 7.09) were the risk factors of LBW.

CONCLUSIONNegative life events might affect LBW and negative life events occurring in the different term of pregnancy impact LBW differently.