Neonatal morbidity after induction vs expectant monitoring in intrauterine growth restriction at term: a subanalysis of the DIGITAT RCT

Abstract

The Disproportionate Intrauterine Growth Intervention Trial at Term (DIGITAT) was a randomized controlled trial that prospectively observed children with suspected intrauterine growth restriction (IUGR) at term. DIGITAT was designed to investigate whether induction of labor for pregnancies with suspected IUGR beyond 36 weeks of gestation reduced neonatal morbidity and mortality compared with an expectant approach with fetal and maternal surveillance. Data from that trial showed no significant differences between the 2 approaches in primary fetal outcomes (a composite of perinatal death, abnormal umbilical arterial cord pH and Apgar scores or admission to neonatal intensive care unit as well as comparable operative delivery rates. However, more children in the induction group than in the expectant group were admitted to an intermediate level of care (48% vs 36%). It was possible that this difference in admissions was due to complications of late prematurity because children in the induction group were born, on average, 10 days earlier than did those in the expectant group. It also seemed possible that the difference was not due to clinically relevant morbidity but was associated with policies for admission to intermediate levels of care related to prematurity. The present study performed secondary analysis of the DIGITAT data to resolve these 2 competing explanations. The net effect of the 2 policies on neonatal morbidity was studied in detail using the Morbidity Assessment Index for Newborns (MAIN) score, a validated outcome measure for neonatal morbidity. Babies born to mothers with suspected IUGR were randomized to either induction (n = 308) or expectant monitoring (n = 315). There were no differences between the induction and expectant group in mean MAIN scores or in MAIN morbidity categories. Neonatal admissions were lower in both groups after 38 weeks of pregnancy than before 38 weeks. This finding suggests that a policy of induction does not increase short-term neonatal morbidity. Moreover, the data show that, when induction for near-term growth restriction is considered because of possible stillbirth, it may be reasonable to delay delivery until 38 weeks.