NATURAL CYCLE IN-VITRO FERTILIZATION-EMBRYO TRANSFER AT THE UNIVERSITY-OF-OTTAWA - AN INEFFICIENT THERAPY FOR TUBAL INFERTILITY

Objective: To describe our experience with natural cycle IVF making cl inical and endocrine comparisons with our standard stimulated cycle IV F program. Design: We attempted 75 natural IVF-ET cycles with hCG give n to preempt the LH surge and compared these with 450 attempts at stan dard superovulation IVF-ET done in our unit during the same time perio d. Patients: Natural cycle patients are normally ovulating women < age 38. Superovulation IVF-ET patients are all <41 years old. Patients in both groups had partners with normal semen parameters and tubal facto r infertility. Main Outcome Measures: Cancellation rates, pregnancy ra tes per egg retrieval, per ET procedure, and luteal phase E2:P ratios of the treatment cycles are compared. Results: There were 35 of 75 (47 %) natural cycle and 112 of 450 (25%) superovulation cycle cancellatio ns. An egg was retrieved in only 24 of 40 (60%) natural cycles and 336 of 338 (99%) superovulation egg retrieval procedures. Pregnancy rates per ovum pick-up procedure were significantly higher: 65 of 338 (19%) in the superovulation versus 2 of 40 (5%) in the natural cycle groups . Pregnancy rates per ET were not significantly different between natu ral IVF-ET, 2 of 18 (11%) and superovulation IVF-ET, 65 of 298 (22%). The E2:P ratios 5 days after ET were similar in both groups at 18 +/- 4 after natural IVF-ET and 21 +/- 18 after superovulation IVF-ET. Conc lusions: 1! Cancellation rates for natural cycle IVF are very high.  2! Midluteal E2:P ratios are the same in both groups. 3! Pregnancy ra tes per egg retrieval are significantly lower for natural versus super ovulation IVF-ET. 4! In our experience, natural cycle IVF-ET is an in efficient therapy for tubal infertility compared with superovulation I VF-ET.