Intrauterine Growth Restriction in the Triad:  Understanding Outcomes Associated with Differential  Management of Severe Early IUGR

Street L,Denney JM,Quinn K,Fore M,Barron T,Nitsche JF

doi:10.18314/cogo.v1i1.1028

Abstract

Objective: Preterm delivery of growth restricted (IUGR) fetuses prior to 32 wks is rarely indicated, occurring in <1.9% of all pregnancies. We sought to determine if delaying delivery until non-reassuring fetal heart tracing (NRFT) increases adverse outcomes. Materials and Methods: This is a cohort of pregnant women with IUGR identified prior to 32wks. Serial fetal growth and umbilical artery Doppler (UAD) were assessed. Two groups were compared: those delivered for abnormal UAD studies and those delivered for non-reassuring fetal heart tracing (NRFHT). Fetuses with absent (AEDF) or reversed end diastolic flow (REDF) were placed on continuous monitoring until delivery. Maternal comorbidities, delivery indications, and neonatal outcomes were compared between the 2 groups. T-test and Chi-square were performed where appropriate. Results: 43 singleton gestations with IUGR were identified at <32 weeks gestation from 2012-2015. Pregnancies were excluded for multiple gestation or when delivered for maternal deterioration. Mean GA at diagnosis 24.7 +/-3.1wks (range 18-30.3wks). 30 delivered for abnormal UAD and 13 for NRFT. Pregnancy characteristics were similar between groups. Those women who progressed to urgent delivery due to NRFT were more likely to undergo cesarean (CD) than SVD (p=0.01). 83.9% of both groups were delivered via CD and were significantly smaller compared to those able to be born via SVD (p=0.026). Women with HTN, preeclampsia or GHTN were also more likely to undergo CD than SVD (p=0.04). Expectant management for abnormal UAD did not decrease requirement for CPR at delivery or incidence of IVH, RDS, or death. Although not statistically significant, the length of stay was 50.9 days in those delivered for Doppler while 61.2 days in the group delivered emergently (p=0.23); see Table 1. Conclusion: Expectant management for fetal growth restriction and waiting to deliver until there was NRFT does not appear to decrease neonatal morbidity/mortality, increases risk for emergency CD, and may increase length of stay in NICU.

Highlights

While obstetric literature is littered with myriad of terms and criteria used to clinically categorize the fetus failing to achieve individual growth potential, one widely accepted convention is to classify a fetus with intrauterine growth restriction (IUGR) when composite biometry measured by ultrasound generates an estimated fetal weight (EFW) at less than the 10th percentile for gestational age [1]
Women that were expectantly managed until evidence of non-reassuring fetal heart tracing (NRFHT) developed (p=0.01) were more likely to require an emergency Cesarean Delivery (CD) than the group delivered based on Doppler studies(Figure1)
The mean maternal age was 27.5 years in the group delivered for abnormal umbilical artery Doppler (UAD) studies and 30.6 in the group delivered for NRFHT was 30.6 (p = 0.15)

Summary

Introduction

While obstetric literature is littered with myriad of terms and criteria used to clinically categorize the fetus failing to achieve individual growth potential, one widely accepted convention is to classify a fetus with intrauterine growth restriction (IUGR) when composite biometry measured by ultrasound generates an estimated fetal weight (EFW) at less than the 10th percentile for gestational age [1]. Using estimated fetal weight of less than the 10th percentile to define IUGR leads to a significant number of false positives when trying to identify the fetuses at increased risk of adverse outcomes This can lead to unnecessary preterm deliveries and iatrogenic increase in neonatal complications. In Europe, it is commonplace to perform a customized assessment of fetal growth accounting for maternal height and ethnicity rather than lock-stock and barrel approach of inserting an estimated fetal weight at a given gestational age into population data irrespective of maternal and paternal contribution Given such considerations, the American College of Obstetricians and Gynecologists (ACOG) does not recommend intervening by way of delivery solely for abnormal umbilical artery Doppler studies; this is meant to avoid unnecessary preterm deliveries [10].

Materials and Methods

Results and Discussion

Conclusion