Materials and Methods: This double-blind, placebo-controlled study included postpartum breastfeeding women in Khon Kaen, Thailand. Mefenamic acid or placebo was administered over the first 12 weeks of DMPA use. Then, participants completed a self-report bleeding diary.

Results: Forty women, initiating the use of DMPA for postpartum contraception, were randomized to mefenamic acid (n=20) or placebo (n=20) group. The study was discontinued after 27 months because of suboptimal enrollment. The mefenamic acid group was less likely to have prolonged bleeding compared to placebo although this was not statistically significant (37.5% vs. 50%, respectively, P = 0.491). DMPA discontinuation rates were high at 50% in both groups although no participants in the mefenamic acid group stopped using DMPA due to bleeding side effects.

Conclusions: The high discontinuation rates in the postpartum use of DMPA are attributed to the occurrence of bleeding/spotting side effects. Although mefenamic acid prophylaxis appeared to be beneficial to some women, a larger randomized controlled trial is required to confirm the effectiveness of this approach.