ASSOCIATION BETWEEN BODY MASS INDEX AND BIRTH DEFECTS - CLEFT LIP AND CLEFT PALATE: A CASE-CONTROL STUDY

Purpose: Orofacial clefts (cleft lip and cleft palate) are birth defects that occur during early stages of prenatal development resulting from incomplete closures of facial structures. The Centers for Disease Control and Prevention (2005) estimated that each year 2,651 babies in the U.S. are born with cleft palate and 4,437 babies are born with cleft lip with or without a cleft palate. The causes of orofacial clefts are unknown but thought to be caused by a combination of genes, family history, and exposure to smoking, alcohol, maternal diet, medication use, diabetes, and being obese. The main purpose of our study is to test whether there is an association between maternal body mass index (BMI) and oral cleft disorders. Methods: We analyzed data on orofacial clefts live births using Texas birth defects registry from 1999 thru 2009 in five counties. The study employed case-control design with randomly matched controls and live birth cases (N= 2887). We used univariate for descriptive, bivariate to assess associations, and logistic regression analysis with BMI as our main risk factor to estimate the adjusted odds with 95% confidence intervals. The incidence rates for each year were estimated per 1000 live births to examine the trend. Results: At the bivariate level, BMI and educational level were significantly associated with oral clefts. Results from the regression analysis indicated that mothers who are obese have nearly 1? times higher odds of having a child with oral clefts when compared to normal weight mothers. Mothers with low educational level also had elevated odds of having a child with oral clefts after adjusting for other confounders. Trend data showed that Tarrant County had higher rate of orofacial defects from 1999 through 2006. Conclusions: Our study suggests a possible risk of orofacial clefts associated with maternal weight and low educational level. Public Health campaigns need to emphasize the importance of peri-conceptional health and pre-pregnancy planning. It is critical to educate women on the importance of diet and nutrition, in particular those with low educational level.