(999) Isolated abdominal circumference vs. estimated fetal weight, which matters more?

Friday, February 10, 2023

3:30 PM – 5:00 PM

Objective: Fetal growth restriction (FGR) is a leading cause of neonatal morbidity and mortality. In 2020, the Society of Maternal Fetal Medicine and the American College of Obstetricians and Gynecologists redefined fetal growth restriction from estimated fetal weight (EFW) less than the 10th percentile to EFW or abdominal circumference (AC) less than the 10th percentile. In our study, we seek to assess the rate of abnormal umbilical artery Doppler velocimetry in fetuses with FGR diagnosed by isolated AC less than the 10th percentile versus those diagnosed by EFW less than the 10th percentile.

Study Design: This retrospective case control study included all singleton non anomalous pregnancies diagnosed with fetal growth restriction between October 2019 to December 2021. Patients were divided based on criteria at time of initial diagnosis of FGR. The study group (iAC group) included patients diagnosed with FGR due to AC less than the 10th percentile and EFW 10th percentile or greater. The control group (EFW group) included patients with EFW less than the 10th percentile regardless of AC percentile. The primary outcome is the rate of abnormal umbilical artery Doppler velocimetry; defined as pulsatility index greater than 95th percentile, absent or reversed end-diastolic velocity.

Results: During the study timeframe 733 patients were diagnosed with FGR. There were 248 patients in the iAC group and 485 in the EFW group. The iAC group had a rate of 10.5% (26/248) of abnormal umbilical artery Doppler velocimetry as compared to 19.8% (96/485) in the control group (p < 0.001). The number needed to treat (NNT) for antenatal testing in fetuses with iAC to detect 1 abnormal umbilical artery doppler is 10.3.The average gestational age at diagnosis was 33.6 weeks for the iAC group and 31.3 weeks for the EFW group (p < 0.001)

Conclusion: The rate of abnormal umbilical artery Doppler velocimetry in patients with isolated AC less than the 10th percentile at first diagnosis of FGR is less than those diagnosed based on EFW less than the 10th percentile. Further studies on this new subset of patients are needed.

Primary & Presenting Author(s)

Fatima Ali, DO (she/her/hers)
Resident
Jersey Shore University Medical Center
Ocean Grove, NJ, United States

Coauthor(s)
JC
Joseph Canterino, MD
Jersey Shore University Medical Center
Neptune, New Jersey, United States

KK
Karen Koscica, DO
Jersey Shore University Medical Center
Neptune, New Jersey, United States

VD
Valeria DiStefano, MD
Department of Obstetrics and Gynecology, Jersey Shore University Medical Center, Hackensack Meridian School of Medicine, Neptune, New Jersey, USA.
Neptune, New Jersey, United States

NA
Noelle Aikman, MD
Department of Obstetrics and Gynecology, Jersey Shore University Medical Center, Hackensack Meridian School of Medicine, Neptune, New Jersey, USA.
Neptune, New Jersey, United States

JF
Jonathan Faro, MD
Jersey Shore University Medical Center
Neptune, New Jersey, United States