Controlled Ovarian Stimulation (COS) is a fertility treatment where medications stimulate the ovaries to produce multiple eggs. It's commonly used with IUI or before IVF to improve fertilization chances. It's ideal for women under 36 with unexplained infertility or mild male factor issues. Less effective for women over 41 or those with blocked tubes.

Treatment Process

Involves oral drugs (Clomid, Letrozole) or injectables (Follistim, Gonal-F, etc.) taken from day 5 of the menstrual cycle to promote the growth of multiple mature follicles.

Success Rates

  • 5–15% per cycle for women under 36
  • Decreases with age
  • IVF is considered after 3 unsuccessful COS cycles or for women over 40