Cabergoline for Lactation Inhibition After Early Second-Trimester Abortion or Pregnancy Loss: A Randomized Controlled...

To evaluate cabergoline's efficacy at decreasing lactation symptoms after early second-trimester abortion or pregnancy loss.

This is a multisite, double-blind, gestational-age stratified superiority trial that compared cabergoline 1 mg once with placebo for preventing bothersome breast symptoms immediately after uterine evacuation. We enrolled pregnant people at 16-20 weeks of gestation who were English- or Spanish-speaking and without contraindication to the study drug. Participants received cabergoline within 4 hours of uterine evacuation or fetal expulsion and, at baseline and at multiple time points through 2 weeks postprocedure, completed a validated electronic survey that assessed breast symptoms, side effects, and bother. Our primary outcome was breast symptoms (a composite of engorgement, milk leakage, tenderness, and need for pain relief) on day 4; we planned to enroll 30 participants in each gestational duration strata to show a 40% difference in breast symptoms (80% power, α=0.049).

After screening 145 patients from February 2024 through May 2025, we enrolled 69 eligible participants. Baseline demographics were balanced between groups: Median gestational duration was 18 weeks (range 16 0/7-19 6/7 weeks), 53.0% were nulliparous, 63.6% self-identified as Hispanic, and 68.2% had public insurance. On day 4, significantly fewer participants who received cabergoline reported any breast symptoms compared with placebo (50.0% vs 88.2%, P<.001) (primary outcome) and fewer participants reported significant bother from breast symptoms (3.1% vs 20.6%, P=.05) (secondary outcome). These differences persist even in the earlier gestational duration strata.

Cabergoline is an effective and well-tolerated medication to prevent breast symptoms after early second-trimester abortion or pregnancy loss.

ClinicalTrials.gov: NCT06029673.