Am J Perinatol 2020; 37(01): 008-013
DOI: 10.1055/s-0039-1694005
SMFM 2019
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

High Fetal Fraction on First Trimester Cell-Free DNA Aneuploidy Screening and Adverse Pregnancy Outcomes

1  Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, Massachusetts
,
Mark A. Clapp
1  Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, Massachusetts
,
Penelope S. Roberts
1  Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, Massachusetts
,
Sarah N. Bernstein
1  Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, Massachusetts
,
Ilona T. Goldfarb
1  Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, Massachusetts
› Author Affiliations
Funding None.
Further Information

Publication History

20 June 2019

25 June 2019

Publication Date:
31 July 2019 (online)

Abstract

Objective To test the hypothesis that high fetal fraction (FF) on first trimester cell-free deoxyribonucleic acid (cfDNA) aneuploidy screening is associated with adverse perinatal outcomes.

Study Design This is a single-institution retrospective cohort study of women who underwent cfDNA screening at <14 weeks' gestation and delivered a singleton infant between July 2016 and June 2018. Women with abnormal results were excluded. Women with high FF (≥95th percentile) were compared with women with normal FF (5th–95th percentiles). Outcomes investigated were preterm birth, small for gestational age, and hypertensive disorders of pregnancy.

Results A total of 2,033 women met inclusion criteria. The mean FF was 10.0%, and FF >16.5% was considered high (n = 102). Women with high FF had a greater chance of delivering a small for gestational age infant <fifth percentile, with an adjusted odds ratio of 2.4 (95% confidence interval: 1.1–4.8, p = 0.039). There was no significant association between high FF and either preterm birth or hypertensive disorders of pregnancy.

Conclusion Women with a high FF in the first trimester are at increased risk of delivering a small for gestational age infant <fifth percentile. Further investigation into the clinical implications of a high FF is warranted.

Note

This study was presented as poster abstract (no. 901) at SMFM's 39th Annual Pregnancy Meeting, Las Vegas, NV, February 11–16, 2019.