Association between maternal body mass index and congenital anomalies: A case‐control study in Tuscany (Italy)

• Published in: Birth defects research 2022-02, Vol.114 (3-4), p.116-123
• Main Authors: Mezzasalma, Lorena, Santoro, Michele, Coi, Alessio, Pierini, Anna
• Format: Article
• Language: English
• Subjects: Body mass; Body Mass Index; Body size; Case-Control Studies; case‐control study; Cleft Lip - epidemiology; Cleft Palate; Confidence intervals; Congenital anomalies; Congenital defects; Education; epidemiology; Female; Humans; Italy - epidemiology; maternal BMI; Mothers; Nervous system; Neural tube defects; Orofacial clefts; Regression analysis; Regression models; Risk; Risk Factors; Social interactions; Statistical analysis; Thinness - complications; Thinness - epidemiology; Underweight
• ISSN: 2472-1727; 2472-1727
• DOI: 10.1002/bdr2.1970

Objective To investigate the relationship between prepregnancy maternal body mass index (BMI) and congenital anomalies (CAs). Design Case‐control study on data collected by the registry of CAs of Tuscany (Italy) and birth certificates from 2005 to 2017. Main exposure Maternal prepregnancy BMI. Main outcome measures Any major CAs and groups of organ‐specific anomalies. Odds ratios (ORs) were estimated using logistic regression models adjusted for maternal factors. Results Maternal BMI ≥25 was significantly associated with all nervous system anomalies (OR = 1.61, 95% confidence interval [95% CI] 1.13–2.29) and with neural tube defects (OR = 2.03, 95% CI 1.00–4.12); maternal underweight was significantly associated with orofacial clefts (OR = 1.67, 95% CI 1.12–2.48). After stratification by education, in the low education group, mothers with BMI ≥25 had an increased risk of nervous system anomalies (OR = 2.19, 95% CI 1.01–4.76), whereas underweight mothers had an increased risk of nervous system anomalies (OR = 3.89, 95% CI 1.44–10.53), orofacial clefts (OR = 2.59, 95% CI 1.24–5.42), and urinary anomalies (OR = 1.74, 95% CI 1.07–2.82). In the medium/high education group, the only significantly increased risk was found in mothers with BMI ≥25 for nervous system anomalies (OR = 1.50, 95% CI 1.00–2.25). Conclusion Main results have shown a positive association of maternal BMI ≥25 with nervous system anomalies and maternal underweight with orofacial clefts. The study has also evidenced the impact of social status and provided clues to the role of maternal ethnic background.