The Impact of the Active Management of Risk in Pregnancy at Term on Birth Outcomes: A Randomized Clinical Trial

Abstract

Although cesarean delivery rates continue to increase, little improvement has resulted in the overall quality of birth outcomes. An alternative approach, active management of risk in pregnancy at term (AMOR-IPAT), uses risk-based preventive induction of labor to make sure that women begin labor at a gestational age that maximizes the chance for vaginal delivery. This approach has, in retrospective studies, been associated with low cesarean delivery rates and improved birth outcomes. Both risk factors that interfere with placental growth or accelerate placental aging and those that promote fetal growth or limit maternal pelvic size are taken into account when estimating the upper limit of the optimal time of delivery (UL-OTD). With active management of risk, labor is planned to begin on or 1 to 4 days before the UL-OTD. Participating in the study were 136 women exposed to AMOR-IPAT and 134 were given usual care. The two groups were well matched for demographics, prenatal variables, and study risk factors. Labor was induced in 58% of exposed women and in 21.6% of the usual-care group. Cesarean delivery rates were similar, 10.3% in the exposed group, and 14.9% in the nonexposed group, and this finding largely persisted after adjusting for parity and short stature. Admission to neonatal intensive care was less frequent for the exposed group (1.5% versus 6.7%). The rate of uncomplicated vaginal birth was higher in the exposed group (73.5% versus 62.8%), and this group had a lower mean Adverse Outcome Index score. There were no significant group differences in rates of low 5-minute Apgar scores or major perineal injuries. High estimated blood loss was more frequent in women given usual care. Infants in the exposed group more often weighed <2500 g at birth, but none of them required neonatal intensive care for this reason. Larger randomized trials in more diverse populations are needed, but the present findings do challenge the belief that inducing labor necessarily leads to adverse birth outcomes.