Sequence of Events Leading to Medical Abortion for Fetal Indications after 34 Weeks' Gestation: 23 Years of Experience in a Single Medical Center.

Introduction: Technical advances are rapidly improving the ability to detect anatomical malformations and genetic abnormalities during pregnancy. We aimed to identify the sequence of events leading to medical abortion ≥34 weeks' gestation, to determine whether the procedure could have been carried out earlier.

Method: Retrospective study of medical abortions in singleton pregnancies carried out in our department over a 23-year period from 1998 to 2021.

Results: 36/4,055 (0.88%) abortions were carried out ≥34 weeks' gestation. The indications were anatomical in 20 (55%), chromosomal or genetic in 14 (39%) and CMV infection in two. Evaluation of the sequence of events suggests that an earlier diagnosis would have been unfeasible before the third trimester in 18 cases (50%) because the disorder was developmental and ultrasound findings would not have presented earlier. By contrast, certain other cases might have been diagnosed earlier if the patient had not delayed routine screening or if screening had been administered on schedule.

Conclusion: In this series, full adherence to local screening tests and protocols, and timely decision-making could have substantially reduced the late abortion rate by as much as half.