Timely antenatal diagnosis of malformations – Still a far cry

Abstract

Background: Some countries where termination of pregnancy is legalized, it is permitted only up to 20 weeks of gestation. Fetal anomaly detection scan (FADS) is usually advised between 18-20 weeks of pregnancy. Despite timely advice most women turn up late and this fails to provide enough time to terminate pregnancy within the law in the event of a severe anomaly.

Objective: To determine the incidence of congenital malformations, and to study the extent of utilisation of ultrsonography for antenatal diagnosis.

Methods: The records of patients (April 2010 – May 2012) who delivered a baby with a congenital malformation, those having undergone termination of pregnancy for malformed fetus and the cases with malformations diagnosed on neonatal autopsy were reviewed. Data was collected in a structured format that included patient characteristics (age, parity, religion, and maternal risk factors), details of antenatal care (period of first visit, prenatal ultrasound for fetal anatomy) and anomalies (ultrasound detection, after termination/ birth).

Results: During the period of review there were 12238 pregnancy records (11675 deliveries after 28 weeks, and 563  expulsions of pregnancies before 28 weeks; excluding ectopic and molar pregnancies) and 121 congenital malformations giving the incidence of malformations as 1.04 per 100 deliveries; and 0.99 per 100 total pregnancy outcomes. The average age of women was 26.6 ± 4.2 years with 5.8% being beyond 35 years of age. The majority of women were multiparous. Only 26.4% had FADS prior to 20 weeks. Sonogram performed anytime during the pregnancy could detect 55.9% (62 of 121)) of congenital malformations suggesting that it was missed in 44.1% cases.  Those who submitted for FADS between 14 – 24 weeks of pregnancy, the malformations were detected in 53.2% of 66 pregnancies. The majority (45.2%) of anomalies diagnosed by ultrasonography were neural tube defects.

Conclusion: Overall detection of malformations is low indicating necessity for specific guidelines for performing FADS.