Profile of Prenatally Diagnosed Major Congenital Malformations in a Teaching Hospital in Nigeria

Abstract

Background: Prenatal diagnosis of major congenital abnormality is one of the main goals of antenatal care, because of its contribution to perinatal morbidity and mortality. Awareness of the profile in terms of rates and spectrum could aid management and prevention strategies. This study aims to determine the profile of congenital malformations, and the relationship between the rates and some maternal socio-demographic and obstetric variables. Methods: A retrospective cross-sectional study of prenatally diagnosed congenital malformations in singleton pregnancies over a four-year period. The ultrasound scan findings and the findings of fetal ultrasonography, together with maternal socio-demographic and obstetric variables, were collected from the ultrasound scan reports or medical records of each pregnancy. Data were analyzed using Microsoft Excel 2010. Results: Among the 968 singleton pregnancies, 78 had major congenital malformation, giving an antenatal rate of 8.04/1000 (0.8%). The first trimester prevalence was comparable with other trimesters. Malformation mostly involved single systems (93.6%), which are mainly central nervous (48.7%) and gastrointestinal/abdominal systems (21.8%). The rate was statistically significant (< 0.0018) in women aged > 35 years. The mean maternal age and parity were 31.4 + 4.7 and 2.8 + 0.4, respectively. The rates of congenital malformation in spontaneously or assisted conceptions were not statistically significant (p = 0.073 and p = 0.085). Conclusion: Maternal age > 35 years and multiparity are important risk factors for congenital malformation. The commonly involved systems are the central nervous and gastrointestinal systems.  Keywords: congenital malformations, prevalence, spectrum, antenatal ultrasound scan, Nigeria