There is no clear evidence in the literature to date of an increase in cancer rates among IVF patients. However, there is definite evidence that continuous use of clomifene citrate for 12 consecutive months, may lead to ovarian cancer. Untreated PCOS has an increased prevalence of endometrial cancer.

The longest period should be 3-4 months. Waiting too long to withdraw can lead to endometrial hyperplasia (abnormal thickening of the lining) If pregnancy is not an issue, staying on the pill will give the added benefit of monthly shedding. If a pregnancy is wished for, the best route to follow would be ovulation induction

New literature supports the fact that excessive stimulation is detrimental to the outcome of an IVF cycle from the point of view that it has a negative effect on the endometrial lining from an implantation point of view. According to ISMAAR, a milder approach may lead to a better outcome.