Poster Session 4
Category: Intrapartum Fetal Assessment
Poster Session 4
Dikla Ben Zvi, MD
Resident
Rambam Health Care Campus
Haifa, Hefa, Israel
Naphtali Justman, MD
Rambam Medical Health Center
Haifa, Hefa, Israel
Julia Fedorkova, MD
Rambam Health Care Campus
Haifa, Hefa, Israel
Gilad Shahak, MD
Rambam Health Care Campus
Haifa, Hefa, Israel
Roee Iluz, MD
Rambam Health Care Campus
Haifa, Hefa, Israel
Ola Gutzeit, MD
Rambam Health Care Campus
Haifa, Hefa, Israel
Michael Y Divon, MD
Department of Obstetrics and Gynecology, Lenox Hill Hospital–Northwell Health
New York, New York, United States
Zeev Weiner, MD
Director of the Obstetrics and Gynecology Division
Rambam Health Care campus
Haifa, Hefa, Israel
The primary objective of this study was to establish a simple, visually identifiable, and clinically relevant criterion for real-time interpretation of fetal heart rate (FHR) monitoring by human observers, aimed at supporting timely recognition of fetal acidemia. We investigated whether the time interval from the last FHR acceleration to delivery could serve as a practical marker to guide intrapartum decision-making.
Study Design:
We conducted a retrospective case-control study using delivery records from term (37–42 weeks), low-risk singleton pregnancies at Rambam Health Care Campus. Eligible cases had vaginal or operative vaginal delivery, umbilical cord blood gas within 30 minutes, and continuous FHR monitoring from the last acceleration until birth. Neonatal acidemia was defined as umbilical pH < 7.0. FHR tracings were reviewed by a blinded reader who annotated the timing of the last acceleration and terminal FHR category. Statistical analysis included ROC curve and bivariate comparisons.
Results:
The study included 149 participants (36 acidemia, 113 controls), the groups were comparable in maternal and neonatal characteristics as well as in the intrapartum course. The incidence of category 3 fetal heart rate (FHR) tracings during labor did not differ significantly between groups (Fisher’s exact test, p = 0.116). The mean interval from last acceleration to delivery was significantly longer in the acidemia group (186.0 vs. 75.7 minutes; p < 0.001). ROC analysis identified 90 minutes as the optimal cutoff (AUC 0.783).
Conclusion:
In term, low-risk pregnancies, a prolonged absence of FHR accelerations prior to delivery is significantly associated with neonatal acidemia. A 90-minute threshold may assist in identifying fetuses at risk. The terminal fetal heart rate pattern and the interval from the last acceleration should be considered complementary markers of evolving neonatal compromise that may be used together to enhance clinical decision-making and improve neonatal outcomes.