RT Journal Article SR Electronic T1 Prenatal NO2 exposure and ultrasound measures of foetal growth: a prospective cohort study in Wuhan, China JF Occupational and Environmental Medicine JO Occup Environ Med FD BMJ Publishing Group Ltd SP 204 OP 210 DO 10.1136/oemed-2016-103980 VO 74 IS 3 A1 Wang, Weiye A1 Zhong, Chunrong A1 Huang, Li A1 Zhou, Xuezhen A1 Chen, Renjuan A1 Wu, Jiangyue A1 Li, Xiating A1 Xiong, Ting A1 Liu, Chaoqun A1 Xiao, Mei A1 Yang, Xuefeng A1 Hao, Liping A1 Yang, Nianhong A1 Wei, Sheng YR 2017 UL http://oem.bmj.com/content/74/3/204.abstract AB Objectives To examine the relationship between prenatal nitrogen dioxide (NO2) exposure and foetal growth in a prospective cohort of 1001 Chinese women.Methods The maternal NO2 exposure levels were estimated using land-use regression models based on home address. The biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL) and estimated foetal weight (EFW) were evaluated via ultrasonography. The multiple linear regression model was used to adjust for confounders, and the mixed-effect model was used to assess longitudinal effect.Results With a 10 μg/m3 increase in NO2 exposure, the BPD, HC, AC, FL and EFW in the second trimester decreased by 0.40 mm (95% CI −0.56 to −0.24), 1.07 mm (95% CI −1.60 to −0.54), 1.02 mm (95% CI −1.57 to −0.48), 0.24 mm (95% CI −0.37 to −0.12) and 7.84 g (95% CI −11.59 to −4.08), respectively; the BPD and HC in the third trimester decreased by 0.26 mm (95% CI −0.50 to −0.02) and 0.71 mm (95% CI −1.37 to −0.06), respectively. The longitudinal analyses showed inverse associations of NO2 exposure with BPD, HC, AC and FL (all p<0.05). The stratified analyses showed that the effects of NO2 on the HC, FL and EFW in the second trimester were stronger among female babies and that the effect of NO2 on EFW in the third trimester was stronger among smoking mothers (all p<0.05).Conclusions In this prospective study of Chinese women, maternal NO2 exposure was inversely associated with foetal growth, and the association was stronger among female babies and smoking mothers.