(150) Subdividing Early Fetal Growth Restriction Based on Gestational Age at Diagnosis: Implications for Perinatal Management

Two distinct phenotypes of fetal growth restriction (FGR) have been identified based on gestational age at diagnosis: early (< 32 weeks) and late (≥32 weeks), with different outcomes observed between these two categories, though this cutoff is debated. We hypothesized differences in early FGR outcomes based on the gestational age at diagnosis.

Study Design:

To test our hypothesis, we conducted a retrospective cohort study on data extracted from our database on 334 women with singleton pregnancies diagnosed with FGR (fetal weight/AC below the 10th percentile). The 1^st ultrasound was at less than 20 weeks’ gestation. Patients were divided into four groups based on the gestational age at diagnosis: Group A (20.0-23.6 weeks), Group B (24.0-27.6 weeks), Group C (28.0-31.6 weeks), and Group D (≥32 weeks).

Outcome measures included:

1. Composite adverse perinatal outcomes (neonatal acidosis, Apgar score < 7 at 5 minutes, perinatal death, severe intraventricular hemorrhage, necrotizing enterocolitis, and respiratory distress requiring intubation)


2. Gestational age at delivery < 37 weeks


3. Mode of delivery

Chi-square, Fisher’s exact test, and pairwise comparisons were used when appropriate, with a p-value < 0.05 indicating statistical significance.

Results: Group A had the highest number of deliveries at < 37 weeks (see Table); however, the difference was significant only when compared to Group D. Composite adverse perinatal outcomes decreased from Group A to Group D, with significant differences between Group A and Group C, and between Group A and Group D (see Figure). Although the cesarean delivery rate declined from Group A to Group D, this change was statistically significant only between Group A and Group D (see Figure).

Conclusion:

Our results highlight the importance of subdividing early FGR by gestational age at diagnosis. This stratification aims to improve perinatal management and outcomes. Further research should focus on optimizing protocols for each FGR subgroup.