TY - JOUR T1 - Maternal lead exposure and premature rupture of membranes: a birth cohort study in China JF - BMJ Open JO - BMJ Open DO - 10.1136/bmjopen-2018-021565 VL - 8 IS - 7 SP - e021565 AU - Sha Huang AU - Wei Xia AU - Xia Sheng AU - Lin Qiu AU - Bin Zhang AU - Tian Chen AU - Shunqing Xu AU - Yuanyuan Li Y1 - 2018/07/01 UR - http://bmjopen.bmj.com/content/8/7/e021565.abstract N2 - Objectives Maternal exposure to lead (Pb) has been suggested to correlate with adverse birth outcomes, but evidence supporting an association between Pb exposure and premature rupture of membranes (PROM) is limited. The aim of our study was to investigate whether maternal Pb exposure was associated with PROM and preterm PROM.Design Cross-sectional cohort study.Study population The present study involved 7290 pregnant women from the Healthy Baby Cohort in Wuhan, China, during 2012–2014.Main outcome measures PROM was defined as spontaneous rupture of amniotic membranes before the onset of labour and was determined with a pH ≥6.5 for vaginal fluid. Maternal urinary Pb level was adjusted by creatinine concentration, and its relationship with PROM was analysed by logistic regression.Results The IQR of maternal urinary Pb concentrations of the study population was 2.30–5.64 µg/g creatinine with a median of 3.44 µg/g creatinine. Increased risk of PROM was significantly associated with elevated levels of Pb in maternal urine (adjusted OR 1.23, 95% CI 1.0 to 1.47 for the medium tertile; adjusted OR 1.51, 95% CI 1.27 to 1.80 for the highest tertile). The risk of preterm PROM associated with Pb levels was significantly higher when compared with the lowest tertile (adjusted OR 1.24, 95% CI 0.80 to 1.92 for the medium tertile; adjusted OR 1.73, 95% CI 1.15 to 2.60 for the highest tertile). In addition, the relationship between Pb and PROM was more pronounced among primiparous women than multiparous women (p for interaction <0.01).Conclusions Our study found that higher levels of maternal Pb exposure was associated with increased risk of PROM, indicating that exposure to Pb during pregnancy may be an important risk factor for PROM. ER -