Pre- and Postoperative Cell-Free Fetal DNA Analyses for Detecting Aneuploidy in Early Pregnancy Loss: Single-Center Prospective Cohort Study

Abstract

Background/Objective: Early pregnancy loss is often caused by chromosomal abnormalities, necessitating accurate diagnostic tools. While product of conception (POC) chromosomal testing is commonly used, it can be limited by culture failure or an inability to obtain fetal tissue due to spontaneous expulsion. Cell-free fetal DNA (cff DNA) analysis provides a non-invasive alternative; however, its effectiveness in early pregnancy loss, particularly in cases where fetal components are still minimal, has not been fully established. The objective of this study was to evaluate the accuracy of pre- and postoperative cff DNA analysis for detecting fetal aneuploidy by comparing the results to those of POC chromosomal testing. Methods: In this single-center prospective cohort study, 50 women undergoing manual vacuum aspiration for pregnancy loss before 12 weeks of gestation were enrolled (February 2022-December 2024). Cff DNA analysis was performed on maternal blood samples collected pre- and postoperatively. The primary outcome was concordance between the cff DNA and POC results. Sensitivity, specificity, and factors affecting concordance were also assessed. Results: Eight participants were excluded due to unsuccessful POC culture (n = 3), suspected maternal tissue contamination in the POC sample (n = 1), mosaicism (n = 3), or triploidy (n = 1), resulting in 42 evaluable cases. Preoperative cff DNA analysis showed 88.1% concordance with POC (sensitivity 86.4% and specificity 90.0%). Postoperative analysis showed 78.6% concordance (sensitivity 72.7% and specificity 85.0%). Conclusions: The Cff DNA analysis of preoperative and postoperative maternal blood samples showed generally good concordance with conventional POC chromosomal testing in detecting fetal aneuploidy in early pregnancy loss.

Keywords: aneuploidy; cell-free fetal DNA; early pregnancy loss; fetal fraction; miscarriage; next-generation sequencing; non-invasive prenatal testing; product of conception testing.

Figure 1

The participant selection flowchart. Women who experienced pregnancy loss before 12 weeks of gestation and were scheduled for manual vacuum aspiration are enrolled. Maternal blood samples are collected preoperatively and postoperatively for cff DNA analysis, and the results are evaluated for concordance with the POC chromosomal testing results.