Clinical application of low-dose misoprostol in the induced labor of 16 to 28 weeks pathological pregnancies (a STROBE-compliant article)

Oral mifepristone combined with rivanol lactate (rivanol) is commonly used in second-trimester pregnancy termination. However, rivanol is not suitable to premature rupture of membranes and oligohydramnios because amniocentesis is difficult. Mifepristone combined with misoprostol is suitable for the patients with oligohydramnios. In accordance with the misoprostol dosing recommendations by the International Federation of Gynecology and Obstetrics (FIGO), the incidences of uterine rupture and cervical laceration are relatively high in Chinese pregnant women. The aim of our study was to optimize misoprostol dosing regimen in terms of efficacy and safety in Chinese pregnant women. We modified the Bishop Score, and then gave patients low-dose misoprostol according to the modified Bishop score. Based on the amniotic fluid volume (AFV) indicated by type-B ultrasonic instrument, the cases with AFV ≤2 cm receiving low-dose misoprostol combined with mifepristone and the cases with amniocentesis failure followed by receiving low-dose misoprostol combined with mifepristone were enrolled into study group, and the cases with AFV >2 cm receiving rivanol combined with mifepristone were enrolled into control group. The start time of uterine contractions, time of fetal expulsion, birth process, hospital day, successful induced labor rate, complete induced labor rate, and incomplete induced labor rate were observed and compared between the 2 groups. There were significant differences in the start time of uterine contractions, time of fetal expulsion, birth process, and hospital day between the control group and the study group (all P < .05). The successful induced labor rate, complete induced labor rate, and incomplete induced labor rate were also significantly different between the 2 groups (all P < .05). In the induced labor of 16 to 28 weeks pathological pregnancy, low-dose misoprostol can markedly improve the successful induced labor rate and complete induced labor rate, shorten the birth process and hospital day, and decrease uterine curettage rate and uterine rupture risk. Low-dose misoprostol combined with mifepristone is suitable to the induced labor of 16 to 28 weeks pathological pregnancy in Chinese women.