Attempts to programme ovulation with exogenous oestrogens and LH-RH analogue

Area of Science:

• Reproductive endocrinology
• Gynecology
• Human reproduction

Background:

• Controlled ovarian stimulation is crucial for assisted reproductive technologies.
• Precisely timing ovulation within the menstrual cycle remains a clinical challenge.
• Previous ovulation induction protocols have shown variable success rates.

Purpose of the Study:

• To investigate the efficacy of various hormonal treatments for programmed ovulation on a specific day of the menstrual cycle.
• To evaluate the predictability and success rate of ovulation induction using different regimens.
• To assess the potential of a long-acting LH-RH analogue for timed ovulation.

Main Methods:

• Surgical observation of ovaries during elective sterilization assessed follicular rupture and ovulation.
• Histological analysis of ovarian and endometrial tissues was performed.
• Multiple hormonal regimens were tested, including clomiphene citrate, HCG, LH-RH, ethinyloestradiol, and human menopausal gonadotrophin, followed by HCG.
• A potent long-acting LH-RH analogue was administered on day 13 post-ethinyloestradiol pretreatment in 10 women.

Main Results:

• Ovulation induction on a predetermined day was seldom achieved with most tested regimens.
• Clomiphene citrate, HCG, synthetic LH-RH, and ethinyloestradiol were largely ineffective for programmed ovulation.
• Human menopausal gonadotrophin followed by HCG was more effective but resulted in multiple ovulations.
• In women pretreated with ethinyloestradiol, a single injection of a long-acting LH-RH analogue on day 13 led to observed ovulation on days 15 or 16 in nine out of ten participants.

Conclusions:

• Standard ovulation induction agents are generally ineffective for precisely programming ovulation on a specific day.
• Human menopausal gonadotrophin followed by HCG can induce ovulation but lacks precision and risks multiple ovulations.
• A long-acting LH-RH analogue, following ethinyloestradiol pretreatment, demonstrates potential for more predictable, timed ovulation induction.