A Decade of Prenatal Genetic Diagnostics: Insights From 1949 Cases at a Medical Genetics Facility in South India.

Objective: Our objective was to report on the performance of prenatal diagnostic procedures for genetic testing in a developing country.

Method: This retrospective study involved a review of medical records of women who underwent prenatal diagnostic procedures from 2014 to 2024 at a Medical Genetics facility in South India. Data on the type of procedure, indication for testing, types of tests, outcomes, and complications of procedures were recorded and analyzed using descriptive statistics.

Results: A total of 1949 procedures were performed; 1126 amniocentesis and 816 chorionic villus sampling. An increasing trend in the number of prenatal diagnostic procedures has been observed over the decade. The most common indication for testing was monogenic disorders (1191/1949; 61.1%), followed by chromosomal disorders (537/1949; 27.6%) and ultrasound abnormalities (199/1949; 10.2%). In case of ultrasound abnormalities, a higher yield of monogenic disorders (39/87; 44.8% by exome sequencing) was observed compared to chromosomal disorders (8/204; 3.9% by karyotype/chromosomal microarray). There were no procedure-related miscarriages reported in our cohort.

Conclusions: This study reiterates the safety of prenatal diagnostic procedures when performed by skilled personnel following standard protocols, even in low-resource settings. Monogenic disorders are the commonest test indication and the predominant cause of ultrasound abnormalities, reflecting the high burden of autosomal recessive disorders in our cohort.