(644) The effect of isolated fetal head circumference < 10% on neonatal outcomes

Friday, February 10, 2023

10:30 AM – 12:00 PM

Objective: While fetal growth restriction and isolated fetal abdominal circumference less than 10% are established risk factors for poor perinatal outcomes, less is known regarding detection of isolated fetal head circumference less than 10%. We evaluated the impact of fetal head circumference less than 10% on perinatal outcomes.

Study Design: This retrospective cohort study analyzed 967 singleton pregnancies with 3rd trimester growth ultrasounds and delivery at our medical center between January 2018 and December 2019. Perinatal outcomes of NICU admission, SGA, APGARs < 7 at five minutes of life, IUFD, and neonatal death prior to discharge were compared between pregnancies with normal growth and head circumference and those with isolated head circumference measurements less than 10%. Chi square testing was performed to compare rates of maternal comorbidities between groups.

Results: Of the 967 pregnancies reviewed, 179 (18.5%) had isolated head circumference measurement less than 10% (HC < 10%). When compared with pregnancies with normal growth and head circumference measurement (n=725, 75.0%), those with HC < 10% had a significantly higher rate of combined perinatal death (IUFD and neonatal death before discharge) (5.0% vs 1.8%; RR=2.80, p=0.0154). Higher rates of NICU, SGA, and APGARs < 7 at five minutes of life were seen in the HC < 10% cohort; though these rates were not statistically significant. Both groups were impacted by similar rates of cHTN, GDM, T1DM, HIV+ status, and hypertensive disorders of pregnancy. More pregnancies in the HC < 10% group were impacted by T2DM (6.70% vs 3.17%; p=0.0014).

Conclusion: Isolated fetal head circumference < 10% is associated with higher rates of perinatal fetal death.

Primary & Presenting Author(s)

Adam Schettler, MD (he/him/his)
University of Virginia
Charlottesvle, Virginia, United States

Coauthor(s)

Gabrielle K. Smith, MD (she/her/hers)
Resident
University of Virginia
Charlottesvle, Virginia, United States

MD
Marisa Duong, BS
University of Virginia
Charlottesville, Virginia, United States

MS
Margaret Selesky, BS
University of Virginia
Charlottesville, Virginia, United States

Megan Whitham, MD
Fellow
University of Virginia
Charlottesville, Virginia, United States

RR
Rebecca Rieck, MD
Attending Physician
University of Virginia
Earlysville, Virginia, United States