What is ovulation induction?

Note on the name: in May 2026, polycystic ovary syndrome (PCOS) was formally renamed polyendocrine metabolic ovarian syndrome (PMOS), following a global consensus process. The old name was inaccurate — the condition affects multiple hormone and metabolic systems, not just the ovaries, and "polycystic" wrongly implies ovarian cysts. Nothing about the condition, its diagnosis or its treatment has changed. Both names will be used side by side for the next few years, and we use PCOS below since that is the term most people know.

Ovulation induction uses medication to prompt the ovaries to develop and release an egg, in women who are not ovulating regularly. PCOS is the commonest reason for it. Letrozole is now generally preferred as first-line treatment in PCOS, having shown better ovulation and live birth rates than clomiphene. Clomiphene remains widely used and is a reasonable alternative. Where tablets do not work, injectable gonadotropins may be used, with closer monitoring. How it runs: tablets are taken for about five days early in the cycle, from around day 2 to 5, followed by ultrasound scans to track follicle growth. Once a follicle is mature, intercourse or IUI is timed accordingly, sometimes with a trigger injection. What to expect realistically: it often takes more than one cycle, and most pregnancies occur within the first three to six ovulatory cycles. If ovulation is achieved but pregnancy is not after that, the approach is usually reconsidered rather than continued indefinitely. The main risk is multiple pregnancy, which is why monitoring matters and why a cycle is sometimes cancelled if too many follicles develop.