Ovulation Induction

Preventing a premature rise in luteinizing hormone (LH) is essential during ovarian stimulation for in vitro fertilization (IVF), because such a rise can reduce the number of eggs collected. Current practice relies on either a daily injectable GnRH antagonist or an oral progestin (PPOS), which requires that all embryos be frozen. Linzagolix is an oral GnRH antagonist already approved for uterine fibroids and endometriosis. It has not previously been used to control ovarian stimulation for IVF; this study represents its first use for this purpose. This is an observational study: participants are not randomly assigned to a treatment. Each woman receives one of three approaches - oral linzagolix, an injectable GnRH antagonist (ganirelix or cetrorelix), or PPOS - chosen by the clinical team based on her individual situation. The three groups are then compared using statistical adjustment for baseline differences between them. The study will enroll approximately 195 women undergoing IVF or ICSI, aged 18 to \[42\], who are not selected based on ovarian reserve. All participants receive individualized gonadotropin stimulation and standard monitoring; only the method used to prevent premature ovulation differs by group. The main question is whether linzagolix leads to a similar number of mature eggs (MII) retrieved compared with the injectable antagonist. The study will also assess how well each approach suppresses LH, safety (including ovarian hyperstimulation), and the number of injections needed.

This randomized controlled trial (RCT) aims to evaluate whether, in infertile women with WHO II/IV ovulatory disorders, a combination of letrozole (LE) and clomiphene citrate (CC) compared to LE alone, result in higher live birth rates. The study is designed as an open-label, multicenter RCT across six fertility clinics in Vietnam. Participants will be randomized into two groups: (1) LE + CC , (2) LE alone. The primary outcome measure is the live birth rate after one treatment cycle. Based on prior data, the live birth rate for IUI in letrozole cycles is estimated at 12%. To detect a 10% increase in live birth rates with CC, 436 couples are needed (α = 0.05, power = 80%). Additionally, the live birth rate after IUI with LE-induced ovulation is approximately 18.7% (Diamond et al., 2015). To detect a 10% increase with CC, 560 couples are required (α = 0.05, power = 80%). Considering a 5% loss to follow-up and protocol deviations, the study plans to recruit 600 participants (150 per arm).