Screening for congenital fetal anomalies in low risk pregnancy: the Kenyatta National Hospital experience

Abstract

Background: Congenital malformations contribute significantly to the disease burden among children globally. A study conducted in Kenya on understanding the burden of surgical congenital anomalies, highlights the need for Kenyan health systems to go beyond the medical dimensions of illness. This could be achieved by linking knowledge of the severe congenital anomalies (CAs) and their impact of varying disability to the delivery of local health services and public health program planning. Subsequently, early detection of these congenital anomalies is vital and can be achieved through fetal ultrasonography. Studies have proven that antenatal ultrasound can successfully diagnose fetal abnormalities in many cases and therefore aid in counseling of parents and planning for early intervention. Although there are studies on screening of congenital anomalies in various populations, very few have been done in the African population and none to the best of our knowledge has been done in Kenya.

Methods: The patients, who underwent routine obstetric ultrasounds, were recruited into the study. The study population comprised patients who were referred from the obstetric clinic, casualty and other clinics within the hospital vicinity. Data of antenatal ultrasounds was statistically analyzed on structured data collection form to determine the prevalence of congenital anomalies.

Results: Fifteen fetal anomalies were diagnosed in 500 women who came for routine ultrasound (3%). The mean age of the mothers was 28.2 years (SD ± 4.5) with an age range from 15 to 44 years. 400 (80%) of the mothers were aged between 27 and 34 years. The most frequently observed fetal anomalies involved the head (8/ 500; 1.6%). Each of the remaining anomalies affected less than 1% of the fetuses and included anomalies of the spine (2/ 500; 0.4%), pulmonary (2/ 500; 0.4%), renal and urinary tract (2/ 500; 0.4%) and skeletal systems (2/ 500; 0.4%). Majority, 9 of 15 (60%) of the fetuses with anomalies detected on prenatal ultrasound resulted in postnatal mortality within days of delivery.

Conclusion: Congenital anomalies prevalence in our setting compares with those found in other studies. From this study, major birth defects are a major cause of perinatal mortality.

Keywords: Low risk; Malformations; Obstetric; Sonography.

Fig. 1

Flowchart of obstetric patient recruitment at KNH radiology unit and follow up

Fig. 2

Histogram showing spectrum of congenital anomalies

Fig. 3

The above images were from a mother in the age range 30–34 years at 38 weeks 5 days gestation who presented with a history of decreased fetal movements. On ultrasound examination, the head showed fused thalami, a monoventricle/holosphere with absent interhemispheric fissure. A diagnosis of alobar holoprosencephaly was made. The other systems were normal. Mortality occurred on the second day post-delivery in the neonatal intensive care unit (NICU)

Fig. 4

The above images were obtained from a mother age range 35–39 years Gravida 2 who was on follow up due to a suspected anomaly on an earlier scan. Her scan showed a huge disparity between the humeral/femur length and other biometric data. The chest was also relatively small. A diagnosis of probable asphyxiating skeletal dysplasia was made. The findings were confirmed upon delivery. The neonate died shortly after delivery due to respiratory complications

Fig. 5

These are images from a mother in the age range 25–29 years Gravida 3 at 31 weeks who presented with a history of fundal height not corresponding to dates. On imaging, both kidneys and the urinary bladder were absent. The thoracic diameter was relatively small likely due to pulmonary hypoplasia and associated oligohydramnios. A diagnosis of bilateral renal agenesis was made. Ultrasonic age corresponded to 25 weeks

Fig. 6

The above images were obtained from a mother age range 30-34 years Gravida 4 on routine sonography to assess fetal wellbeing. She had had previous normal pregnancies and was not on folate supplementation. The scans showed a ventricular atrial diameter of 20.1 mm and a diagnosis of ventriculomegaly was made

Fig. 7

These images are from a mother age range 25–29 years Gravida 3 who presented with a history of abdominal pain and fundal height not corresponding to dates. On examination, the stomach was not visualized during the entire scan period and there was polyhydramnios. A possibility of esophageal atresia was entertained. Upon delivery, the mother reported inability to feed and was informed of a possible “cardiac problem”. Unfortunately, infant demise occurred a few days post-delivery

Fig. 8

This image was obtained from a mother age range 35–39 years Gravida 3 on a routine obstetric scan. Examination showed an anteriorly placed sacrococcygeal mass likely a teratoma. All the other systems were normal. The diagnosis was confirmed postnatally, with the neonate on follow up at the surgical clinic