1 Introduction
Gonadotropin-releasing hormone (GnRH) antagonists are currently widely
used for controlled ovarian stimulation (COS). GnRH antagonists have the
advantage of preventing severe ovarian hyperstimulation syndrome (OHSS)
by using GnRH agonists as the final oocyte maturation trigger instead of
human chorionic gonadotropin (hCG), which has a long
half-life1,2.
Preventing premature ovulation (PO) completely is difficult. However, Wu
et al.3 reported three cases of pregnancy by oocyte
retrieval from residual follicles after PO. Additionally, Vicdan et
al.4 reported five cases of PO that were converted
from in vitro fertilization (IVF) to intrauterine insemination
(IUI) and two became pregnant. In most cases of PO, it is noticed and
the IVF cycle is canceled. Therefore, there have been few reports of
successful cases of pregnancy after PO.
We report a case of spontaneous pregnancy due to PO in a GnRH antagonist
protocol. No signs of a premature luteinizing hormone (LH) surge or PO
were observed, despite monitoring LH levels and the follicle count
during the COS. Additionally, luteal function was maintained even after
the GnRH agonist trigger so the pregnancy continued, and a healthy live
neonate was delivered.