Efficacy and safety of oral versus vaginal misoprostol for medical management of first trimester missed abortion: A systematic review and meta-analysis

Background: Missed abortion in the first trimester is characterized by the cessation of embryonic or fetal development while the cervix remains closed, often resulting in little to no bleeding. Ultrasound examinations typically reveal an empty gestational sac or an embryo/fetus that lacks cardiac activity. Misoprostol is the primary medication used to manage early pregnancy loss.

Objectives: To compare the efficacy of misoprostol, orally and vaginally in management of first trimester missed abortion."

Study selection: This systematic review included randomised control trials of patients with a confirmed diagnosis with first-trimester missed abortion, comparing oral and vaginal misoprostol for uterine evacuation success, induction-expulsion time, patient satisfaction and adverse events.

Data extraction and analysis: Ten studies were included in this meta-analysis. All of them are RCTs with a number of patients 1,142 [578 in oral misoprostol group and 564 in vaginal misoprostol group]. Independent data extraction and quality assessment ensured unbiased results. We estimated risk ratios (RR) with 95% CIs using random-effects meta-analysis and evaluated quality of the included studies using Cochrane's Risk of Bias tool (RoB 2).

Results: We included 10 studies in our analysis and for our primary outcome, vaginal misoprostol had a higher success rate, [RR: 0.85, P = 0.004], shorter induction-expulsion interval [MD:4.95, P = 0.0001], and greater patient satisfaction compared to oral administration [RR:0.85, P = 0.01]. Secondary outcomes revealed significantly higher nausea and vomiting in the oral group, with no significant difference in headache, dizziness, diarrhea, fever, excessive bleeding, or discharge. Severe crampy pain was also significantly higher in the oral group.

Conclusion: Our comprehensive review and meta-analysis indicate that the vaginal route of misoprostol is the most effective method for managing first-trimester missed abortions. This route achieves a significantly higher success rate and shorter induction- to-expulsion interval, along with greater patient satisfaction during follow-up sessions and fewer side effects.