Epidemiological Risk Factors and Perinatal Outcomes of Congenital Anomalies

Objectives To identify the epidemiological risk factors for congenital anomalies (CAs) and the impact of these fetal malformations on the perinatal outcomes. Methods This prospective cohort study comprised 275 women whose fetuses had CAs. Maternal variables to establish potential risk factors for each group of CA and perinatal outcomes were evaluated. The primary outcome was CA. Secondary outcomes included: fetal growth restriction (FGR); fetal distress (FD); premature rupture of membranes (PROM); oligohydramnios or polyhydramnios; preterm delivery (PTD); stillbirth; cesarean section; low birth weight; Apgar score < 7 at the 1st and 5th minutes; need for assisted ventilation at birth; neonatal infection; need for surgical treatment; early neonatal death; and hospitalization time. Chi-square (χ(2)) test and multilevel regression analysis were applied to compare the groups and determine the effects of maternal characteristics on the incidence of CAs. Results The general prevalence of CAs was of 2.4%. Several maternal characteristics were associated to CAs, such as: age; skin color; level of education; parity; folic acid supplementation; tobacco use; and history of previous miscarriage. There were no significant differences among the CA groups in relation to FGR, FD, PROM, 1-minute Apgar score > 7, and need for assisted ventilation at birth. On the other hand, the prevalence of the other considered outcomes varied significantly among groups. Preterm delivery was significantly more frequent in gastrointestinal tract/abdominal wall defects. The stillbirth rate was increased in all CAs, mainly in isolated fetal hydrops (odds ratio [OR]: 27.13; 95% confidence interval [95%CI]: 2.90-253.47). Hospitalization time was higher for the urinary tract and congenital heart disease groups (p < 0.01). Neonatal death was significantly less frequent in the central nervous system anomalies group. Conclusion It was possible to identify several risk factors for CAs. Adverse perinatal outcomes were presented in all CA groups, and may differ according to the type of CA considered.