Outcome of successive cycles of ovulation induction in the same individual.

Because of the failure to conceive after the first cycle of in vitro fertilization (IVF), many couples often undergo repeated attempts. However, choosing the best stimulation protocol in successive cycles of IVF in the same individual is hindered by the lack of information regarding outcome in successive cycles following utilization of the same or different stimulation protocols. Examination of repeated cycles of the same stimulation protocol in 33 women demonstrated that comparing women with an initial "A" estradiol (E2) pattern (daily E2 levels that continued to rise throughout the stimulation) and those with non-A E2 patterns (failure to have continually rising E2 levels throughout the stimulation), the former were significantly less likely to have a subsequent passed cycle (P = 0.007) and tended to be more likely to have a subsequent A cycle (P = 0.079). Changing the stimulation protocol resulted in a different E2 pattern in 15 of 20 subsequent cycles. Thus, it is suggested that after a cycle with an acceptable E2 pattern, successive cycles be performed with the same stimulation protocol. However, after an initial unacceptable E2 pattern, it may be more efficacious to utilize an alternate stimulation protocol.