Introduction: Abortion is common worldwide and increasingly abortions are performed at less than 14 weeks' gestation using medical methods, specifically using a combination of mifepristone and misoprostol. Medical abortion is known to be a painful process, but the optimal method of pain management is unclear. We sought to identify and compare pain management regimens for medical abortion before 14 weeks' gestation.

Study design: We conducted our search in August 2019 and included randomized controlled trials (RCT) and observational studies of any pain relief intervention (pharmacological and non-pharmacological) for mifepristone-misoprostol combination medical abortion of pregnancies less than 14 weeks' gestation.

Results: We included four RCTs and one observational study. Due to the heterogeneity of study designs, interventions and outcome reporting, meta-analysis was not possible. Only one study found evidence of an effect between interventions on pain score: a prophylactic dose of ibuprofen 1600mg likely reduces the pain score when compared to a dose of paracetamol 2000mg (MD 2.26/10 [CI 3-1.52 lower]). For other interventions (pregabalin 300mg vs placebo; ibuprofen 800mg vs placebo; therapeutic vs prophylactic administration of ibuprofen 800mg; ambulation vs non-ambulation during treatment) there appeared to be little to no difference with comparator.

Conclusions: The findings of this review provide some support for the use of ibuprofen as a single dose given with misoprostol prophylactically, or in response to pain as needed. The optimal dosing of ibuprofen is unclear, but a single dose of ibuprofen 1600mg was shown to be effective and it was less certain whether 800mg was effective.