Oocyte yield and live birth rate after follitropin delta dosing and fresh embryo transfer: an individual patient data meta-analysis

Research question: What number of retrieved oocytes is associated with the optimum chance of achieving a live birth for women undergoing ovarian stimulation with individualized follitropin delta?

Design: An individual patient data meta-analysis was performed on 1772 patients from five randomized controlled trials using individualized follitropin delta for ovarian stimulation with fixed daily dosing based on serum anti-Müllerian hormone (AMH) level and body weight. Live birth rate (LBR) and ovarian hyperstimulation syndrome (OHSS) were evaluated in relation to the number of oocytes retrieved. Predicted LBR was obtained using a logistic regression analysis with fractional polynomials. Subgroup analyses were performed based on number of oocytes retrieved, age and AMH level.

Results: The analysis included patients treated with follitropin delta who had at least one oocyte retrieved. The mean number of oocytes retrieved was 10.4, and overall LBR was 32.1%. Predicted LBR increased with the number of oocytes retrieved, reaching >34% for patients with 8-14 oocytes retrieved, and peaking at 34.9% for patients with 11 oocytes retrieved. LBR declined gradually beyond retrieval of 14 oocytes. LBR was 27.8%, 33.6% and 30.9% for patients with 1-7, 8-14, and ≥15 oocytes retrieved, respectively. LBR decreased with increasing age: 32.7%, 30.7% and 23.4% at <35, 35-37 and 38-42 years, respectively. The incidence of OHSS (any grade) was 2.1%, 5.2% and 17.0% for patients with 1-7, 8-14, and ≥15 oocytes retrieved, respectively.

Conclusions: After ovarian stimulation with individualized follitropin delta, LBR in fresh transfer cycles was highest for patients with 8-14 oocytes retrieved, and peaked in patients with 11 oocytes retrieved. The results support the appropriateness of the follitropin delta dosing algorithm.