358: Declining NICU admissions in uncomplicated fetal growth restriction following adoption of ACOG/SMFM practice guidelines

Abstract

Our department followed a policy of delivery at 37weeks in suspected fetal growth restriction (FGR) based on the interpretations of DIGITAT data. Following the publication of ACOG/SMFM Practice Bulletin 134, we changed practice to delivery at the recommended gestational age of 38-396 weeks in uncomplicated FGR. We hypothesized that infants with FGR delivered between 38-396 weeks would have lower rates of NICU admission compared to those delivered at 37weeks. We completed a retrospective cohort study of singleton pregnancies at our institution delivered January 2011 to December 2018. Following former policy, deliveries at 37weeks with suspected FGR (ultrasound estimated fetal weight < 10% within 3weeks of delivery), were compared to deliveries following adoption of new guidelines for delivery at 38-396weeks in cases of suspected FGR. We included groups at 37weeks and 38-396weeks in spontaneous labor with suspected average for gestational age (AGA) fetuses for baseline comparison. We excluded infants with neonatal abstinence syndrome. Primary outcome was NICU admission. Multiple logistic regression was performed to evaluate the relative impact of infant birthweight, gestational age, and neonatal morbidities in prediction of NICU admission. Significance was set at P< 0.05. NICU admissions were higher in early-term infants delivered for suspected FGR following prior policy of delivery at 37weeks, when compared to infants delivered at 38-396weeks following adoption of ACOG/SMFM recommendations, 16.8% vs 3.2% (odds ratio 6.08; 95% CI,1.71-21.6; P=0.002). According to multivariable analysis, predictors of NICU admission include neonatal morbidity (hyperbilirubinemia requiring treatment, O2 requirement, hypoglycemia, hypothermia), low Apgar scores, and younger gestational age at delivery. Infant birthweight < 10% (SGA) was not associated with NICU admission. Our data support the ACOG/SMFM recommendation of delaying delivery to 38-396weeks in uncomplicated FGR. Younger gestational age, and not SGA status, is an independent predictor of NICU admission in this group of infants.View Large Image Figure ViewerDownload Hi-res image Download (PPT)