(498) Antenatal Fetal Surveillance: Impact on pregnancy outcomes

Thursday, January 30, 2025

4:00 PM – 6:00 PM

Submitting Author and Presenting Author(s)

Hannah S. Foster, MA, MD (she/her/hers)

Department of Obstetrics and Gynecology, University of Pennsylvania, Perelman School of Medicine
Philadelphia, PA, United States

Coauthor(s)

JW

Jessica Wu, MD

Department of Obstetrics and Gynecology, University of Pennsylvania, Perelman School of Medicine
Philadelphia, Pennsylvania, United States
MF

Markolline Forkpa, MPH

Pennsylvania Medicine Women's Health Clinical Research Center
Philadelphia, Pennsylvania, United States
JC

Jesse Chittams, MS

University of Pennsylvania School of Nursing
Philadelphia, Pennsylvania, United States
NW

Nehemiah Weldeab, MPH

University of Pennsylvania School of Nursing
Philadelphia, Pennsylvania, United States
JM

Jennifer Mccoy, MD

Assistant Professor, Maternal Fetal Medicine
Department of Obstetrics and Gynecology, University of Pennsylvania, Perelman School of Medicine
Philadelphia, Pennsylvania, United States
Nadav Schwartz, MD

Professor, Maternal Fetal Medicine
University of Pennsylvania, Perelman School of Medicine
Philadelphia, Pennsylvania, United States

Objective: Serial antenatal testing is often recommended for high-risk pregnancies to reduce the stillbirth risk. However, the impact of testing recommendations on delivery outcomes is not well-studied. We explored how fetal testing impacts delivery outcomes to better inform patients.

Study Design: In this retrospective cohort, we identified all singleton pregnancies that delivered at 1 of 3 hospitals within an academic health system between 1/2022 and 5/2023. We then identified those that had undergone serial outpatient antenatal testing and collected testing indication and recommendations for the final testing visit prior to delivery. Primary outcomes included iatrogenic delivery < 39 weeks, iatrogenic preterm birth < 37 weeks (PTB), cesarean delivery (CS), and NICU admission. Stepwise regression models were used to assess the association between demographic variables and testing indications and outcomes.

Results: A total of 3992 patients were included, with 480 (12.1%) recommended for delivery based on their final test. Overall, 370 (9.3%) were sent for delivery < 39 weeks and 161 (4.0%) patients were sent for iatrogenic PTB. Testing patients sent for delivery had a 50.4% CS rate, which was significantly higher than the CS rate amongst those not sent for delivery due to a testing visit (37.4%, P< 0.001). Overall NICU admission rate was 12.6% (N=501). Nulliparity was only associated with increased likelihood of CS (aOR: 1.2; 1.0-1.4); whereas race was not associated with any of the outcomes. There were significant differences in NICU admission by hospital, likely related to NICU protocols. Several testing indications were significantly associated with each outcome (Table 1).

Conclusion: For patients undergoing antenatal testing, there is an overall low risk of iatrogenic preterm delivery or delivery prior to the 39-week elective induction window. Certain testing indications are associated with increased risk of adverse pregnancy outcomes. These data can be used to help high-risk patients understand their pregnancy risks when being recommended for serial fetal testing.