Analysis of Environmental Exposures for Nonsyndromic Cleft Lip and/or Palate: A Case-Control Study

Background: orofacial cleft is among the most common developmental malformations in humans. this study aimed to identify the relationship between environmental factors and nonsyndromic cleft lip and/or palate (nscl/p) in northwest china. methods: this case-control study was conducted in gansu province, china over two years (jan. 1, 2017–jan. 1, 2019). overall, 600 nscl/p cases and 660 normal control cases were finally enrolled in the current study. data were collected by conducting face-to-face interviews with both parents of each case. results: univariate (χ2) analysis revealed 22 factors as being significantly associated with nscl/p. multivariate (stepwise logistic regression) analysis identified that 14 factors had statistically significant association with nscl/p. male gender (or=0.789), paternal age at childbirth of 25-29 yr (or=0.690), and folic acid supple-ment (or=0.197) were found to be protective factors against nscl/p. on the other hand, blood a-type, multiple births, positive family history of nsclp (or=6.660), parental consanguinity (or=6.107), positive abortion history, high or low maternal childbearing age, and maternal passive smoking (or=4.349), malnutrition (or=4.431), infections, and drug use (or=2.188) during early gestation were significant risk factors for nscl/p. conclusion: parental age at childbirth of 25–29 yr, and folic acid supplement can reduce the risk of nscl/p. by contrast, maternal passive smoking, infections, and drug use during early gestation period, and multiple births, parental consanguinity, positive family history, and maternal abortion history can increase the risk of nscl/p. identification of risk factors is essential in minimizing the incidence of nscl/p in a particular population.