O05Cabergoline for lactation inhibition after second-trimester abortion or loss: A randomized controlled trial

Abstract

<h3>Objectives</h3> To assess cabergoline's efficacy at decreasing lactation after second-trimester abortion or loss. <h3>Methods</h3> This is a double-blinded, block-randomized superiority trial (IRB approved, NCT04701333) comparing cabergoline 1mg once to placebo for preventing bothersome breast engorgement after second-trimester uterine evacuation. April 2021-June 2022, we enrolled pregnant people 18-28-weeks gestation, English- or Spanish-speaking, without contraindication to the study drug. Participants completed a validated, piloted, electronic survey at baseline and through two weeks post-procedure assessing breast symptoms, side-effects, and bother at each time point. Our primary outcome is breast symptoms on day 4; we planned to enroll 80 patients to show a 30% difference in breast symptoms (80% power, α = 0.049). A sub-group of participants returned for serum prolactin levels. <h3>Results</h3> After screening 150 patients, we enrolled 73 participants. Baseline demographics were balanced between groups: median gestational age 21 weeks (range: 18-26), 56% nulliparous, 35% self-identified as Hispanic, 37% with public insurance. At baseline, reported breast symptoms were similar between groups. At day 4, significantly fewer participants receiving cabergoline reported any symptoms compared to placebo (27.8% vs 97.0%, p<0.0001) and fewer reported significant bother (2.8% vs 29.7%, p=0.002). These differences persisted through day 14. Reported side-effects (p=0.31) were similar between groups: most common were constipation (44%), fatigue (32%), and headache (29%). Serum prolactin was similar at baseline. On day 4, mean serum prolactin was 6.5ng/mL (std dev 2.2) for those receiving cabergoline and 18.0ng/mL (std dev 5.9) for placebo (p=0.04). <h3>Conclusions</h3> Cabergoline is an effective strategy to prevent breast symptoms following second-trimester abortion or loss.