Impact of a Potential 20-Week Abortion Ban on Likelihood of Completing Required Views in Second-Trimester Fetal Anatomy Ultrasound

Am J Perinatol. 2024 Apr;41(6):771-777. doi: 10.1055/s-0042-1749138. Epub 2022 May 16.

Abstract

Objective: The aim of this study was to quantify the likelihood of assessing all mandated fetal views during the second-trimester anatomy ultrasound prior to the proposed federal 20-week abortion ban.

Study design: Retrospective cohort study of a random sample of 1,983 patients undergoing anatomy ultrasound in 2017 at a tertiary referral center. The difference in proportion of incomplete anatomic surveys prior compared with after 20-week gestation was analyzed using X 2 and adjusted logistic regression; difference in mean days elapsed from anomaly diagnosis to termination tested using t-tests and survival analysis.

Results: Incomplete views were more likely with initial ultrasound before 20 weeks (adjusted relative risk: 1.70; 95% confidence interval: 1.50-1.94); 43.5% versus 26.1% were incomplete before and after 20 weeks, respectively. Fetal structural anomalies were identified in 6.4% (n = 127/1,983) scans, with 38.0% (n = 49) identified at follow-up after initial scan was incomplete. 22.8% (n = 29) with an anomaly terminated.

Conclusion: A complete assessment of fetal views during an anatomy ultrasound prior to 20-week gestation is often not technically feasible. Legislation limiting abortion to this gestational age would greatly impact patient's ability to make informed choices about their pregnancies.

Key points: · It is often not technically possible to complete anatomy ultrasound prior to 20-week gestation.. · Often, anomalies are missed during early, incomplete anatomy ultrasounds.. · After the diagnosis of a structural anomaly, one in five chose to terminate the pregnancy..

MeSH terms

  • Abortion, Induced*
  • Female
  • Gestational Age
  • Humans
  • Pregnancy
  • Pregnancy Trimester, First
  • Pregnancy Trimester, Second
  • Retrospective Studies
  • Ultrasonography, Prenatal*