Secondhand smoke during the periconceptional period increases the risk for orofacial clefts in offspring. Issue 5 (26th July 2018) - Pi, Xin
Abstract: Background: To examine whether exposure to secondhand smoke (SHS) during the periconceptional period among nonsmoking women is associated with an increased risk for orofacial clefts (OFCs) in offspring in a population with low rates of maternal active smoking but high rates of SHS exposure. Methods: We recruited 240 women with OFC‐affected pregnancies and 1420 women who delivered healthy infants from a population‐based case‐control study in northern China during 2002 and 2016. Data including self‐reported SHS exposure were collected by trained health care workers through face‐to‐face interviews. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were used to estimate the association between SHS exposure and OFC risk. Results: The unadjusted ORs for OFCs and cleft lip with or without cleft palate (CL±P) in association with SHS exposure were both 1.6 (95% CI 1.2, 2.1). After adjusting for maternal fever or flu, farming occupation, infant sex, and history of pregnancy affected by birth defects, the adjusted ORs were both 1.6 (95% CI 1.2, 2.2). Frequent SHS exposure (>6 times/week) was associated with an even higher risk for OFCs (adjusted OR 2.6, 95% CI 1.8, 3.8) and for CL±P (adjusted OR 2.5, 95% CI 1.7, 3.7). Conclusions: Maternal SHS exposure during the periconceptional period increases the risk for OFCs in offspring among nonsmoking mothers.