Traditionally, we have learned that any imbalance in the estrogen: progesterone relationship can trigger irregular uterine bleeding. That makes sense, right? During anovulation, prolonged unopposed estrogen can result in HMB. In such a case, we give progesterone as both a therapeutic as well as diagnostic intervention. On the contrary, with progestin only contraception, we consider estrogen predominant products when progesterone breakthrough bleeding (BTB) occurs to restore endometrial stabilization. But a new RCT (AJOG) adds credence to adding MORE progesterone in cases of progesterone associated BTB. Listen in for details.

1. Zigler RE, Madden T, Ashby C, Wan L, McNicholas C. Ulipristal Acetate for Unscheduled Bleeding in Etonogestrel Implant Users: A Randomized Controlled Trial. Obstet Gynecol. 2018 Oct;132(4):888-894. doi: 10.1097/AOG.0000000000002810. PMID: 30130351; PMCID: PMC6153077.

2.ANDRADE MCR, et al. Norethisterone for Prolonged Uterine Bleeding Associated with Etonogestrel Implant (IMPLANET): A Randomized Controlled Trial, American Journal of Obstetrics and Gynecology (2025), doi: https://doi.org/10.1016/j.ajog.2025.08.029.