Alternative to Intensive Management of the Active Phase of the Second Stage of Labor: A Multicenter Randomized Trial (Phase Active du Second STade Trial) Among Nulliparous Women With an Epidural

Abstract

ABSTRACT The optimal management of second stage of labor, with its passive and active phases, remains controversial. In France, delayed pushing during the active phase is recommended because of the belief that, based on older data, the fetus is at higher risk during the active phase. It is possible that uterine contractions combined with maternal pushing can lead to cord compression and reduce placental perfusion and oxygenation, which can induce acidosis and fetal heart rate abnormalities, resulting in the need for medical intervention, such as operative vaginal delivery (OVD) or episiotomy. In countries where the active phase is limited, women are encouraged to push as strongly as possible to speed delivery. However, if the active second stage of labor is prolonged, this intensive management may increase fetal hypoxia. The aim of this study was to examine the effect of moderate pushing versus intensive pushing in the second stage of labor on the risk of neonatal morbidity. This was a multicenter, randomized controlled trial at 13 French maternity units between January 2017 and May 2020. Included were nulliparous, adult women who had spontaneous or induced, uncomplicated delivery of a singleton fetus at ≥37 weeks of gestation. Excluded were women with a psychiatric condition, a disease contraindicating intensive expulsive efforts, or any uterine surgical scar, as well as those with a fetus that was small for gestational age, had congenital abnormalities, or had abnormal heart rate. Eligible women were randomized into 2 groups: the intervention group was instructed to push moderately only during the active phase of the second stage of labor, and the control group was instructed to push intensively during the same phase following French recommendations. Midwives asked the intervention group to push 2 times during each contraction and to take a break with no pushing in 1 of 5 contractions. No limit was set on pushing duration. The control group was asked to push 3 times per contraction without breaks. After 30 minutes of pushing, the midwife contacted an obstetrician to consider operative delivery. The primary outcome was a composite of neonatal acidosis, a 5-minute Apgar score <7, and/or severe neonatal trauma. Secondary neonatal outcomes were transfer to the neonatology unit or intensive care unit need for resuscitation at birth and need for hypothermia. Secondary maternal outcomes were mode of delivery, postpartum hemorrhage (PPH), and severe PPH. The trial was stopped prematurely because of difficulties obtaining an adequate sample size. Of the 3380 women initially planned, 1710 (50.6%) were included. Ultimately, the intention-to-treat analysis included 809 women in each group. The neonatal morbidity rates for the intervention group and control group were 18.9% and 20.6%, respectively (risk ratio [RR] 0.92; 95% confident interval [CI], 0.75–1.12; P = 0.38). No significant differences were observed for neonatal transfer or need for resuscitation. All but 16 women delivered vaginally. The intervention or moderate pushing group had a longer pushing duration than the control or intensive pushing group (38.8 ± 26.4 vs 28.6 ± 17.0 minutes; P < 0.001) and lower episiotomy rate (13.5% vs 17.8%; RR, 0.76; 95% CI, 0.60–0.95; P = 0.02). The rates of OVD were 21.1% in the intervention group and 24.8% in the control group (RR, 0.85; 95% CI, 0.71–1.02; P = 0.08). No significant differences were observed for PPH or severe PPH. During the active stage of labor, encouraging women to push moderately versus intensively was not associated with decreased neonatal morbidity. Although the pushing duration was longer among women instructed to push moderately, the rate of episiotomy was lower.