Pattern and distribution of prenatally diagnosed congenital anomalies among high risk pregnant women in Ibadan, South Western Nigeria.

Introduction: Congenital anomalies (CA) are structural or functional disorders present at birth. Routine prenatal ultrasound screening has become an indispensable tool for early detection of CA in developed countries which will facilitate appropriate preemptive actions for safe guarding the health of both mother and the unborn fetus. The prevalence of CA in the general population has been researched widely but very few studies exist on the prevalence of CA among high risk pregnancies. Aims and objective: the aim of this study was to determine the prevalence and pattern of congenital anomalies among high risk pregnant women in Ibadan, South West, Nigeria. Methods: this multicenter cross sectional study was conducted in three different hospitals in Ibadan, South West, Nigeria between August 2018 and July 2019. High risk pregnant women that met the inclusion criteria were recruited for the study. Participants underwent detailed fetal anomaly scans at gestational ages between 18-26 weeks during the study period using a Voluson P6 ultrasound machine (GE Healthcare Korea). Written informed consents were obtained from the participants. All the fetuses with ultrasound diagnosed congenital anomalies were followed up till either termination of pregnancy or delivery. Ethical approval was obtained for the study. The data were analyzed using SPSS. Results: a total of 418 high risk pregnant women underwent detailed fetal anomaly scan and CAs were detected in 13(3.1%) of them. Spontaneous abortion was the most common maternal risk factor reported although the association between it and congenital anomaly was not significant. The highest number of anomalies were detected in the genitourinary system while the least was in the central nervous system. Conclusion: the prevalence of high risk pregnant women is high in our environment but the incidence of CA among them is similar to that reported in the general population. Thus, prenatal ultrasonographic screening for congenital anomalies is necessary for all pregnant women irrespective of their risk status.