# Planned mode of delivery and neonatal outcomes in pregnancies complicated by late-onset fetal growth restriction: a retrospective cohort study

## TL;DR

This study found that planned induction of labor is safer than planned cesarean delivery for late-onset fetal growth restriction, reducing neonatal complications.

## Contribution

The study provides evidence that planned induction of labor is associated with better neonatal outcomes compared to planned cesarean delivery in late-onset fetal growth restriction.

## Key findings

- Planned induction of labor was associated with lower adjusted risk of severe neonatal outcomes (aOR 0.35).
- Planned induction of labor also reduced moderate neonatal outcomes (aOR 0.43).
- Results were consistent using both SMFM and ISUOG criteria for defining late-onset fetal growth restriction.

## Abstract

Fetal growth restriction (FGR) is a major contributor to perinatal morbidity and mortality. While guidelines address timing of delivery, the optimal mode—induction of labor (IOL) versus planned cesarean delivery (CD)—remains uncertain.

To evaluate the association between planned mode of delivery and neonatal outcomes in pregnancies complicated by late onset FGR (LOFGR).

We conducted a retrospective cohort study at a tertiary Canadian center (2017–2022). Singleton pregnancies with LOFGR (> 34 weeks’ gestation), defined by Society for Maternal–Fetal Medicine (SMFM) criteria, were eligible if the last ultrasound was within 14 days of delivery. Exclusions included spontaneous labor, delivery < 34 weeks, and contraindications to labor. Planned mode of delivery (IOL vs CD) was the exposure. Outcomes were classified as severe (perinatal death, 5-min Apgar < 4, umbilical arterial pH < 7.05, base deficit ≥ 12 mmol/L, hypoxic-ischemic encephalopathy/therapeutic hypothermia, grade III–IV intraventricular hemorrhage, necrotizing enterocolitis, sepsis, or invasive ventilation > 24 h) or moderate (NICU stay > 72 h, Apgar 4–6, pH 7.05–7.10, non-invasive respiratory support > 6–12 h, transient tachypnea, or brief resuscitation). Multivariable logistic regression adjusted for confounders. A prespecified subgroup applied the ISUOG criteria.

Of 12,270 deliveries, 1,143 (9.3%) met SMFM criteria for LOFGR; 869 were eligible (192 planned CD, 677 IOL). Severe outcomes and moderate outcomes were more frequent after CD (23.4% vs 16.7%; p = 0.03 and 42.2% vs 31.2%; p < 0.01, respectively). IOL was associated with lower adjusted risk of severe outcomes (aOR 0.35; 95% CI 0.19–0.67) and moderate outcomes (aOR 0.43; 95% CI 0.24–0.76). Results were consistent using ISUOG criteria (aOR 0.33; 95% CI 0.17–0.62 and aOR 0.44; 95% CI 0.25–0.79, respectively) About 20% of induced patients required intrapartum CD.

IOL was associated with reduced severe and moderate neonatal morbidity compared with planned CD. IOL represents a safe alternative when intrapartum surveillance and timely operative delivery are available.

The online version contains supplementary material available at 10.1007/s00404-026-08357-8.