Determinants of low birth weight among newborns delivered in China: a prospective nested case-control study in a mother and infant cohort

This nested case-control study aimed to investigate the determinants of low birth weight among newborn babies delivered in Shenzhen, Guangdong, China. We recorded socio-demographic data, health status before pregnancy, pregnancy outcomes and complications in a Shenzhen mother and infant cohort. Among 8951 cases, 401 (4.48%) had low birth weight and 1.65% were full-term with LBW. Maternal body mass index, family income, history of pregnancy, hypertension before pregnancy, vaginal bleeding in 1st trimester, pregnancy-related diabetes, hypertension, placenta previa, placental abruption, premature rupture of membrane, oligohydramnios, and placental types were significantly associated with low birth weight (P < 0.05). In this study, high-risk and mainly preventable factors were linked to low birth weight. Adequate antenatal care, proper maternal nutrition and implementation of proven strategies to prevent high-risk factors may be effective ways to reduce the incidence of low birth weight.What is already known on this subject? Low birth weight (LBW) is associated with adverse perinatal outcomes and neonatal disease and death. The aim of this study was to investigate the factors affecting low birth weight infants in a developed region in China.What the results of this study add? According to this study, the incidence of LBW in Shenzhen of China was 4.48%. Maternal body mass index, family income, history of pregnancy, hypertension before pregnancy, vaginal bleeding in 1st trimester, pregnancy-related diabetes, hypertension, placenta previa, placental abruption, premature rupture of membrane, oligohydramnios, and placental types were significantly associated with LBW.What the implications are of these findings for clinical practice and/or further research? This study suggests that good prenatal care, maternal nutrition and implementation of proven strategies to manage high-risk factors are needed to prevent and reduce the incidence of LBW. Health care providers could use our findings to identify good antenatal care and provide individualised interventions targeting women with risk factors.