Outcomes Among Neonates After a Diagnosis of Persistent or Transient Fetal Growth Restriction Delivered at Term.

Objective To evaluate whether transient fetal growth restriction (FGR) that resolves prior to delivery confers a similar risk of neonatal morbidity as uncomplicated fetal growth restriction that persists at term. Study Design This is a secondary analysis of a medical record abstraction study of singleton live-born pregnancies delivered at a tertiary care center between 2002 and 2013. Pregnancies with either persistent or transient FGR who delivered at 38 weeks or later were included. Patients with abnormal umbilical artery Doppler studies were excluded. Persistent FGR was defined as estimated fetal weight (EFW) < 10%ile from diagnosis through delivery. Transient FGR was defined as EFW < 10%ile on at least one ultrasound, but not on the last ultrasound prior to delivery. The primary outcome was a composite of neonatal morbidity: Neonatal Intensive Care Unit admission, Apgar < 7 at 5 minutes, neonatal resuscitation, arterial cord pH < 7.1, Respiratory Distress Syndrome, Transient Tachypnea of the Newborn, hypoglycemia, sepsis or death. Baseline characteristics and obstetric and neonatal outcomes were compared using Wilcoxon rank-sum and Fisher's exact test. Log binomial regression was used to adjust for confounders. Results Of 777 patients studied, 686 (88%) had persistent FGR and 91 (12%) had transient FGR. Patients with transient FGR were more likely to have a higher body mass index, gestational diabetes, diagnosed with FGR earlier in pregnancy, have spontaneous labor and deliver at later gestational ages. There was no difference in the composite neonatal outcome (RR 1.03, 95% CI, 0.72, 1.47) for transient versus persistent FGR after adjusting for confounders (aRR 0.79, 95% CI 0.54, 1.17). There were no differences in cesarean delivery or delivery complications between groups. Conclusion Neonates born at term after transient FGR do not appear to have differences in composite morbidity compared to those where uncomplicated fetal growth restriction persists at term.