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CME Credit Offered
CME Credit Offered
Abstract Award
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Poster Session 2

(468) Timing of Delivery in Pregnancies Complicated by Small for Gestational Age with Concurrent Chronic Hypertension

Thursday, January 30, 2025
4:00 PM – 6:00 PM  
Objective: The American College of Obstetricians and Gynecologists recommends delivery at 34 0/7 - 37 6/7 weeks for pregnancies complicated with fetal growth restriction and concurrent maternal conditions, such as chronic hypertension (CHTN), based on limited evidence. Our objective was to assess neonatal morbidity at birth for each week of gestation in births complicated with small for gestational age (SGA) and CHTN to assess optimal timing of delivery between 34 0/7 - 37 6/7 weeks.

Study Design: This was a population-based cohort study of non-anomalous, singleton, live births complicated by CHTN and SGA between 34 and 37 completed weeks using data from the U.S. Natality Vital Statistics Database from 2015 to 2022. Planned deliveries were births at each completed week from 34 to 37 weeks that had a labor induction or cesarean delivery without labor, excluding spontaneous labor. Expectant management group included all births that delivered on or after the following week (i.e., planned birth at 34 0/7-34 6/7 compared to all births ≥ 35 0/7 weeks). The primary outcome was a neonatal adverse composite, which was compared between both groups at each week using multivariable analyses. 

Results:

There were 157,985 births that met inclusion criteria. After adjusting for the differences between both groups, planned delivery prior to 36 weeks was associated with greater odds of neonatal morbidity than those expectantly managed (planned 34 weeks birth: 20.3% vs expectant births > 35 weeks: 7.1%, aOR 3.83, 95% CI 3.12-4.70; planned 35 weeks birth: 13.8% vs expectant births > 36 weeks: 5.8%, aOR 2.18, 95% CI 1.74-2.75). Planned delivery ≥ 36 0/7 had similar odds of composite neonatal morbidity than those expectantly managed (Figure 1).

Conclusion:

In births complicated by SGA and concurrent CHTN, planned delivery prior to 36 weeks was associated with greater odds of neonatal morbidity compared to expectant management. This data suggests that optimal delivery timing is ≥ 36 weeks. A randomized trial is needed to confirm these findings.