Related Experiment Video
Updated: Nov 29, 2025
Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives
Published on: September 16, 2021
How effective are the non-conventional ovarian stimulation protocols in ART? A systematic review and meta-analysis
Demian Glujovsky1,2, Romina Pesce3, Mariana Miguens4
1Argentine Cochrane Centre, Institute for Clinical Effectiveness and Health Policy (IECS), Center for Research in Epidemiology and Public Health, National Scientific and Technical Research Council (CONICET), Ravignani 2024, C1414CPV, Buenos Aires, Argentina. demian.glujovsky@gmail.com.
Purpose:
To compare the effectiveness of starting the ovarian stimulation on the early follicular phase ("Conventional") with the newer range of non-conventional approaches starting in the luteal phase ("Luteal"), random-start, and studies implementing them in DuoStim ("Conventional"+"Luteal").
Methods:
Systematic review. We searched CENTRAL, PubMed, and Embase, on March 2020. We included randomized and non-randomized controlled trials that compared "Luteal," random-start ovarian stimulation or DuoStim with "Conventional"; we analyzed them by subgroups: oocyte freezing and patients undergoing ART treatments, both, in the general infertile population and among poor responders.
Results:
The following results come from a sensitivity analysis that included only the low/moderate risk of bias studies. When comparing "Luteal" to "Conventional," clinically relevant differences in MII oocytes were ruled out in all subgroups. We found that "Luteal" probably increases the COH length both, in the general infertile population (OR 2.00 days, 95% CI 0.81 to 3.19, moderate-quality evidence) and in oocyte freezing cycles (MD 0.85 days, 95% CI 0.53 to 1.18, moderate-quality evidence). When analyzing DuoStim among poor responders, we found that it appears to generate a higher number of MII oocytes in comparison with a single "Conventional" (MD 3.35, 95%CI 2.54-4.15, moderate-quality evidence).
Conclusion:
Overall, this systematic review of the available data demonstrates that in poor responders, general infertile population and oocyte freezing for cancer stimulation in the late follicular and luteal phases can be utilized in non-conventional approaches such as random-start and DuoStim cycles, offering similar outcomes to the conventional cycles but potentially with increased flexibility, within a reduced time frame. However, more well-designed trials are required to establish certainty.
