# Unraveling Perinatal Risks in Small-for-Gestational-Age vs. Adequate-for-Gestational-Age Fetuses: Is a Pathological Cerebroplacental Ratio a Red Flag for All?

## TL;DR

This study compares perinatal outcomes in small and adequate-for-gestational-age fetuses with abnormal cerebroplacental ratios, finding worse outcomes in the small group.

## Contribution

The study provides new evidence on the differential impact of pathological cerebroplacental ratios in SGA versus AGA fetuses.

## Key findings

- SGA fetuses with pathological CPR were delivered earlier and more frequently within seven days of diagnosis.
- SGA neonates had lower APGAR scores, lower cord pH, and higher NICU admission rates compared to AGA neonates.
- Caesarean sections due to fetal distress were more common in SGA fetuses, while failed inductions were more frequent in AGA fetuses.

## Abstract

Introduction

The association between pathological cerebroplacental ratio (CPR) and perinatal outcomes has garnered significant attention in obstetric research, particularly with regard to fetal growth patterns. This study aims to explore the implications of pathological CPR in small-for-gestational-age (SGA) fetuses compared with those classified as adequate-for-gestational-age (AGA). In clinical practice, CPR assessment has gained prominence due to its potential to improve decision-making regarding the timing and mode of delivery in pregnancies complicated by growth restriction. Previous research has shown that an abnormal CPR may indicate compromised fetal well-being, necessitating closer surveillance and intervention. However, several studies have also demonstrated that CPR has limited predictive performance when used as a routine screening tool for adverse perinatal outcomes at 36 weeks' gestation. This prospective observational cohort study seeks to provide further insight into the relationship between pathological CPR and perinatal outcomes in AGA and SGA fetuses, thereby contributing to improved maternal-fetal care.

Objective

The objective of this study is to assess and compare perinatal outcomes in SGA and AGA fetuses with pathological CPR, with a focus on delivery characteristics and early neonatal complications.

Methods

A prospective cohort study was conducted over 18 months at the All India Institute of Medical Sciences, Raipur, enrolling 80 pregnant women (>36 weeks’ gestation) with pathological CPR. Participants were categorized as SGA (<10th percentile, n = 40) or AGA (>10th percentile, n = 40) based on estimated fetal weight. Weekly follow-ups included clinical assessments and Doppler studies, with management guided by the Barcelona protocol. Outcomes were recorded at delivery and during the first week of neonatal life.

Results

SGA fetuses (n = 40, 50%) were delivered at an earlier gestational age (37.68 ± 1.15 vs. 38.3 ± 0.99 weeks; p < 0.05) and more frequently within seven days of diagnosis (31/40 (77.5%) vs. 20/40 (50%)). Caesarean section due to fetal distress was significantly more common in the SGA group (18/21 (85.71%) vs. 9/19 (47.37%); p = 0.017), while failed induction occurred more often in AGA fetuses (6/19 (31.58%) vs. 1/21 (4.76%); p = 0.04). SGA neonates had lower APGAR scores at five and 10 minutes and lower mean cord pH (p = 0.003). NICU admissions (13/39 (33.33%) vs. 10/40 (25%)), respiratory distress, and early neonatal deaths were also more common in the SGA group, although not all differences reached statistical significance.

Conclusions

Pathological CPR in SGA fetuses is associated with earlier delivery and poorer neonatal outcomes compared with AGA fetuses, despite similar management. These findings underscore the importance of incorporating CPR assessment into fetal surveillance while avoiding unnecessary interventions in AGA fetuses with pathological CPR.