Abstract
OBJECTIVE: This crossover study compared the effects of two recombinant follicle-stimulating hormone (rFSH) preparations, follitropin alfa and follitropin delta, on assisted reproductive technology (ART) outcomes. METHODS: Patients aged 25-42 years (body mass index: 18-30, anti-Müllerian hormone level ≤2.03 ng/mL) underwent two oocyte retrieval cycles, one with follitropin alfa and the other with follitropin delta, and were divided into four groups based on the crossover use of these preparations. Eighty-one patients received follitropin alfa during both cycles. Fifty-one patients received follitropin delta during both cycles. Forty-four patients received follitropin delta during the first cycle and follitropin alfa during the second cycle. Thirty patients received follitropin alfa during the first cycle and follitropin delta during the second cycle. RESULTS: There was no significant difference in the rate of increase in the number of oocytes retrieved between the first and second cycles, regardless of whether follitropin alpha or follitropin delta was used initially. No significant difference in the blastocyst formation rate was observed. However, cycles in which follitropin alfa was used for the first stimulation and follitropin delta for the second showed a significantly smaller decline in oocyte yield compared to cycles that began with follitropin delta followed by follitropin alfa. CONCLUSION: The present study concluded that in non-polycystic ovary syndrome (PCOS) patients with an anti-Müllerian hormone (AMH) level of ≤2.03 ng/mL - classified as intermediate responders - the use of follitropin delta (12 μg) in the second in vitro fertilization (IVF) cycle resulted in a significantly smaller change in the number of retrieved oocytes compared to the first cycle. This suggests that the use of follitropin delta in the second cycle may be a viable and proactive option in such cases.