A Reduced Dose of Cabergoline for Lactation Inhibition After Second-Trimester Abortion or Pregnancy Loss

Most people do not expect breast engorgement following a second-trimester pregnancy loss yet nearly all report bothersome symptoms. Prolactin is the primary hormone responsible for milk production. The dopamine agonist class, including cabergoline, prevents prolactin release, leading to lactation inhibition. Based on dose-finding studies after a full-term birth, a one-time dose of cabergoline 1 mg is offered for lactation inhibition for full-term fetal/neonatal loss or for those with contraindications to breastfeeding. Recently, our own research found a single dose of cabergoline 1 mg effectively prevents breast symptoms after a second-trimester abortion or stillbirth. However, cabergoline is relatively expensive and associated with side effects such as dizziness, headache, and nausea. As serum prolactin levels are much lower in the second trimester, it is plausible that a lower dose of cabergoline may still be effective in preventing lactation following a second-trimester loss. Our overarching hypothesis is that a lower dose of cabergoline given after a second-trimester abortion or pregnancy loss will still prevent breast symptoms while also decreasing the frequency and severity of side effects. A lower dose would additionally save money for the healthcare system and patient. For this pilot study, we first plan to test whether a lower dose of cabergoline can reduce serum prolactin levels to physiologic levels. This is a pilot double-blinded, gestational-age stratified trial of those with fetal demise, stillbirth, or seeking abortion care between 16- and 26-weeks gestation. The investigators will determine if the proportion of participants receiving cabergoline 0.5 mg with normal serum prolactin level on Day 4 is non-inferior to those receiving cabergoline 1 mg.