Second trimester induced abortions due to fetal anomalies-a population-based study of diagnoses, examinations and clinical management.

Introduction: Two-thirds of induced abortions after gestational week (gw) 18 are performed due to fetal anomalies. The potential of the fetus to survive outside the uterus after birth is the upper limit for induced abortions in Sweden. Due to advances in neonatal medicine, fetal viability and the upper limit of late induced abortions have been converging over the last few decades. The aim of the study was to examine clinical management of fetal anomalies, including time frames, leading to second trimester abortions.

Material And Methods: All induced abortions due to fetal anomalies after gw 11+6 in Uppsala county, Sweden, from 2010 to 2017, were reviewed from electronic medical records in a retrospective descriptive study. In total, 180 women underwent 185 abortions divided into 107 (57.8%) in an early group (gw 12+0 to 18+0), and 78 (42.2%) in a late group (≥ gw 18+1). Examinations performed were genetic testing, fetal echocardiography, magnetic resonance imaging (MRI) and pediatric counseling. Time frames from suspicion of fetal anomaly to abortion were reviewed.

Results: Anomalies were subdivided into groups of diagnosis: chromosomal (n = 104), central nervous system (n = 22), heart (n = 12), urinary tract (n = 10) and others (n = 37). Chromosomal anomaly was present in 82 (76.6%) in the early group and 22 (28.2%) in the late group. In the early group, examinations performed preceding a conclusive diagnosis were mainly QF-PCR for trisomies (n = 97), microarray (n = 13), and genetic counseling (n = 14). In the late group, trisomy test was performed in 68, microarray in 31, MRI in 24, fetal echocardiography in 28, and pediatric or genetic counseling in 43 and six cases, respectively. Mean time interval from suspicion of fetal anomaly to the woman's decision was 5 days before gw 18+1, 7 days in gw 18, and 13 days in gw 21. More than two examinations before reaching the decision to terminate the pregnancy were needed in two abortions (25.0%) in gw 18, increasing to 16 (80.0%) in gw 21.

Conclusions: Increasing complexity and diversity in fetal diagnoses require time-consuming examinations in late-induced abortions compared with earlier gestational weeks. A structured expedient process is necessary to allow for decision time and minimize terminations approaching the legal limit.