(1132) Should abdominal circumference <3rd percentile be included in the definition of severe fetal growth restriction?

Friday, February 10, 2023

3:30 PM – 5:00 PM

Objective: Fetal growth restriction (FGR) is defined as an estimated fetal weight (EFW) or abdominal circumference (AC) < 10th percentile (%) for gestational age (GA). An EFW < 3rd % for gestational age (GA) is considered severe FGR (sFGR). It remains unknown if fetuses with isolated AC < 3rd %, should be considered sFGR. Our primary objective is to assess prediction of small for gestational age (SGA) birth weight in fetuses with an AC < 3^rd % and overall EFW 3rd-9th % to those with an EFW < 3rd %. Our secondary objective is to assess composite neonatal outcome between the two groups.

Study Design: This retrospective case control study was undertaken at a tertiary academic center from January 2016 to December 2022. Inclusion criteria were singleton fetuses with an EFW < 3rd % (Group 1) or AC < 3rd % with EFW 3rd-9th % (Group 2) at 28 weeks gestation or greater. Exclusion criteria were multiple pregnancies, presence of a fetal anomaly, genetic syndrome or infection. Composite neonatal outcome was defined by any of the following: NICU admission >48 hours, necrotizing enterocolitis, sepsis, respiratory distress syndrome, mechanical ventilation, retinopathy of prematurity, seizures, intraventricular hemorrhage, stillbirth, or death before discharge.

Results: A total of 760 patients fulfilled our study criteria, with 495 in Group 1 and 265 in Group 2. Maternal demographics and medical comorbidities are listed in Table 1. For SGA at birth, a positive predictive value (PPV) of 93.5% and 74.3% was noted for Group 1 and Group 2 respectively [OR 4.56, 95% Confidence Interval 2.85-7.31)]. The composite neonatal outcome occurred in 291 (58.8%) fetuses in Group 1 and 66 (24.9%) fetuses in Group 2 (p < 0.001).

Conclusion: An AC < 3rd% with an EFW 3rd-9th % has a PPV of 74% for SGA at birth and is associated with significant neonatal morbidity in 25% of fetuses. Consideration should be given to include an AC < 3^rd % in the definition of sFGR.

Primary & Presenting Author(s)

RH
Rebecca Horgan, MD
Eastern Virginia Medical School
Norfolk, Virginia, United States

Coauthor(s)

LN
Lea Nehme, MD
Eastern Virginia Medical School
Norfolk, VA, United States
HJ
Hannah J. Jensen, BS
Medical Student
Eastern Virginia Medical School
Norfolk, Virginia, United States
AS
Anika P. Shah, BS
Medical Student
Eastern Virginia Medical School
Norfolk, Virginia, United States
RS
Ryan C. Saal, BS
Medical Student
Eastern Virginia Medical School
Norfolk, Virginia, United States
Kazuma Onishi, MD, MPH
Research Fellow
Eastern Virginia Medical School
Norfolk, Virginia, United States
Tetsuya Kawakita, MD, MS, FACOG
Assistant professor
Eastern Virginia Medical School
Norfolk, Virginia, United States
Juliana Gevaerd Martins, MD (she/her/hers)
MD
Eastern Virginia Medical School
Virginia Beach, Virginia, United States
Alfred Abuhamad, MD
President, Provost and Dean
Eastern Virginia Medical School
Norfolk, Virginia, United States