Am J Obstet Gynecol MFM. 2023 May 19:101026. doi: 10.1016/j.ajogmf.2023.101026. Online ahead of print.
ABSTRACT
BACKGROUND: Induction of labor is a common intervention in obstetrics worldwide. Foley catheter is commonly used mechanical method for labor induction in nulliparous women with an unfavorable cervix at term. We hypothesize that a higher volume of FC (80 ml vs. 60 ml) will shorten the induction-delivery interval for labor induction in nulliparous women at term with an unfavorable cervix with simultaneous use of vaginal misoprostol.
OBJECTIVE: To evaluate the effect of trans-cervical foley catheter (80 vs. 60 ml) with simultaneous use of vaginal misoprostol on the induction-delivery interval in nulliparous women at term with an unfavorable cervix for IOL.
STUDY DESIGN: In this double-blind, single-center, randomized controlled trial, nulliparous women with a term singleton gestation with the unfavorable cervix were randomized to either group 1 [FC (80 ml) simultaneously with vaginal misoprostol 25µg every 4h] or group 2 [FC (60ml) with vaginal misoprostol 25µg every 4h]. The primary outcome was induction-delivery interval. Secondary outcomes were duration of the latent phase of labor, number of doses of vaginal misoprostol required, mode of delivery, and maternal & neonatal morbidity. Analyses were based on the intention-to-treat method. A sample size of 100 women per group (n=200) was selected.
RESULTS: Between September 2021 to September 2022, 200 nulliparous women at term with an unfavorable cervix were randomized to labor induction with either Foley catheter (80 ml vs. 60 ml) & vaginal misoprostol. Induction delivery interval (in min) was statistically significantly shorter in Foley catheter (80 ml) (median [IQR]; 604 [524-719] vs. 846 [596-990], [p<0.001]). Median time to labor onset (in min) (240 [120-300] vs. 360 [180-600], p<0.001) was also shorter in group 1 (80ml). The number of doses of misoprostol required for labor induction was statistically significantly less than with 80ml (mean±SD; 1.4±0.7 vs. 2.4±1.3, p<0.001). There was no statistically significant difference in the mode of delivery (n) (vaginal delivery; 69 vs. 80 OR; 0.55[1.1-0.3], p=0.104 & cesarean section; 29 vs. 17 OR; 0.99[3-9-1], p=0.063 respectively). The relative risk of delivery within 12h with 80ml was 2.4 [95% CI 1.68-3.43], with p-value <0.001. Maternal & neonatal morbidity was similar across the two groups.
CONCLUSION: Foley catheter (80ml) simultaneously with vaginal misoprostol significantly shortens the induction-delivery interval (p<0.001) in nulliparous women at term with an unfavorable cervix, as compared to Foley catheter 60 ml & vaginal misoprostol.
CLINICAL TRIAL REGISTRATION: The trial was registered prospectively in the Clinical Trial Registry of India (CTRI) www.ctri.nic.in (registration number CTRI/2021/09/036921, date; 28-09-2021).
PMID:37211088 | DOI:10.1016/j.ajogmf.2023.101026
