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Updated: Feb 6, 2026

Z-Scores for Assessing Ovarian Reserve in Young Patients Undergoing Fertility Preservation
Published on: October 25, 2024
Risk of progesterone elevation in patients with low ovarian reserve using long-acting FSH IVF protocol: a randomized
Enrico Papaleo1, Antonio Quartucci1, Mara Zanirato1
1Obstetrics and Gynaecology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy.
Research Question:
Does the long-acting stimulation protocol with corifollitropin alfa (CFA) followed by daily low-dose recombinant FSH (r-FSH) reduce the risk of premature progesterone elevation (PPE) in women with low ovarian reserve compared with daily high-dose r-FSH?
Design:
This randomized controlled trial, conducted from February 2022 to May 2024, enrolled 110 patients who met the Bologna criteria for poor ovarian responders. Participants were randomized into two groups: the intervention group received long-acting CFA followed by daily 150 IU r-FSH from day 8; and the control group received daily 300 IU r-FSH. The primary outcome was the proportion of patients with progesterone ≥1.1 ng/ml on the day of human chorionic gonadotrophin trigger. Secondary outcomes included number of retrieved oocytes, fertilization rate, fresh embryo transfer rate, and pregnancy rate.
Results:
A significantly lower rate of PPE was observed in the CFA group compared with the control group [2/56 (3.6%) versus 12/54 (22.2%), respectively]. CFA stimulation was associated with an 89% reduction in the odds of PPE (OR 0.11, 95% CI 0.02-0.55; P = 0.007). Fresh embryo transfer was achieved in 34/52 (65%) patients in the CFA group versus 21/48 (44%) patients in the control group (P = 0.04).
Conclusions:
Ovarian stimulation with long-acting CFA plus daily 150 IU r-FSH significantly reduced the risk of PPE and increased the feasibility of fresh embryo transfer in patients with low ovarian reserve. This strategy may offer a better approach for managing PPE, and may improve overall IVF success for this specific patient population.
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