Exploring the safety and diagnostic utility of amniocentesis after 24 weeks of gestation: a retrospective analysis

Objectives: This study aims to describe the indications, complications, yield, and safety of amniocentesis beyond 24 weeks for prenatal diagnostic procedures along with the associated maternal and fetal outcomes.

Methods: A retrospective analysis was conducted on 60 pregnant women (with 61 fetuses) who underwent amniocentesis at or beyond 24 weeks from March 2021 to June 2023 at a tertiary care referral center. Data was collected from medical records and individual patient followups. Descriptive data was collected on patient demographics, amniocentesis indications, and the test results. The other outcomes analyzed were the procedure-related complications and pregnancy outcomes.

Results: The mean gestational age at time of the procedure was 25^4/7 (24^1/7-33^1/7). The most common indication for late amniocentesis was abnormal sonographic findings (44/61, 72.13 %), with structural anomalies being the commonest (21/61, 34.44 %). There were no complications related to the procedure. Of the 60 women, 88.3 % (53/60) continued their pregnancies, while 11.66 % (7/60) opted for termination of pregnancy, and two patients had intrauterine fetal demise (2/61, 3.27 %). Genetic testing revealed abnormalities in 6.55 % (4/61) of cases. Of the 51 pregnancies, 39 delivered vaginally (76.47 %; 39/51) and 12 (23.52 %; 12/51) required caesarean sections. There were five neonatal and infant deaths due to heart defects (2), metabolic syndrome, congenital diaphragmatic hernia, and non-immune hydrops, respectively.

Conclusions: Amniocentesis, done at a later gestation, is a safe and an effective tool for prenatal diagnosis and provides an opportunity to make a genetic diagnosis and further counseling.