I have read that some people have success taking Clomid on days 5-9 instead of days 3-7. Under what circumstances should this be done? How does changing the days affect the results? Can blood tests alone show if the Clomid did or didn't work?

Ann

It makes no difference to success rates whether you start clomiphene on day 3 or day 5 (with day 1 being the first day of real menstrual flow). Clomiphene (Clomid, Serophene) is an anti-estrogen medication that prompts ovulation by fooling the brain into believing that your ovary is slacking off. The brain responds by releasing the hormones LH and FSH, which send the message to the ovary to get busy. LH stimulates ovarian production of male hormones, while FSH stimulates the development of the follicle, egg and the enzymes necessary to convert the male hormones to estrogen.

Ovulation induction predominantly requires FSH. Very little LH is necessary to achieve normal growth of the eggs and sufficient estrogen levels to prepare the uterine lining. I prefer that my patients begin clomiphene on day 3 of the cycle rather than day 5, as this shifts the balance between LH and FSH to slightly favor FSH release. Also, by starting a bit earlier, it is more likely that you will ovulate around day 14 -- the day most women ovulate.

The best clomiphene results are achieved when active monitoring is carried out.