Routine vaginal examination scheduled at 8 vs 4 hours in multiparous women in early spontaneous labor: a randomized controlled trial

BACKGROUND

Vaginal examination can cause pain and embarrassment, but it is recommended to be performed at least every 4 hours to monitor progress in labor. Trial data are sparse on its ideal frequency. Haste to diagnose labor dystocia, especially in low-risk multiparous women, and to resort to oxytocin augmentation and operative delivery may be counterproductive.

OBJECTIVE

This study aimed to evaluate scheduling the first follow-up vaginal examination at 8 vs 4 hours after diagnosis of early spontaneous labor (cervical dilatation of 3–5 cm) in multiparas.

STUDY DESIGN

A randomized controlled trial was conducted from October 2023 to October 2024 in a university hospital. Multiparas at term were recruited at diagnosis of early spontaneous labor. Participants were randomized to vaginal examination scheduled at 8 or 4 hours. Interim vaginal examination was permitted as clinically indicated. The 2 primary outcomes were the time to birth (noninferiority hypothesis) and maternal satisfaction assessed using a 0-to-10 numerical rating scale (superiority hypothesis). Data were analyzed using the t test, Mann–Whitney U test, chi-square test (or Fisher exact test), as appropriate.

RESULTS

A total of 254 women were randomized (127 to each arm). Participants’ characteristics across trial arms were similar. The interval from diagnosis of early labor to birth was mean±standard deviation 4.1±3.0 hours in the 8-hour arm vs 4.5±2.8 hours in the 4-hour arm (mean difference, −0.5; 95% confidence interval, −1.2 to 0.3 hours; P=.218), which was noninferior within the prespecified 2-hour margin. The score of maternal satisfaction with the allocated vaginal examination experience was significantly lower in the 8-hour arm (median [interquartile range], 8 [7–9] vs 9 [8–9]; P<.001) (11-point 0-to-10 numerical rating scale). The number of vaginal examinations from labor diagnosis to second stage was median (interquartile range) 1 (1–2) vs 1 (1–2) (P=.006; mean±standard deviation, 1.4±0.6 vs 1.6±0.8; mean difference, −0.2; 95% confidence interval, −0.1 to −0.4; P=.007), the oxytocin augmentation rates were 22.0% (28/127) vs 34.6% (44/127) (relative risk, 0.64; 95% confidence interval, 0.42–0.95; P=.026), the epidural analgesia rates were 7.1% (9/127) vs 15.0% (19/127) (relative risk, 0.47; 95% confidence interval, 0.22–1.00; P=.045), and the rates of recommendation of the allocated intervention to a friend were 83.5% (106/127) vs 100% (127/127) (P<.001) in the 8- and 4-hour arms, respectively. In the 8-hour arm, the first vaginal examination was more likely to be indicated by a bearing-down sensation or nonreassuring fetal heart rate tracing, and less likely to be performed as scheduled at 8 hours. The rates of cesarean delivery, maternal fever, perineal injury, and postpartum hemorrhage were not different. Neonatal outcomes, including Apgar scores, umbilical cord artery blood pH, base excess, and admission also did not differ significantly.

CONCLUSION

First vaginal examination scheduled at 8 hours compared with 4 hours was noninferior for the time interval to birth, but maternal satisfaction was significantly lower.