Related Experiment Video
Updated: May 29, 2026

Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives
Published on: September 16, 2021
["Flare up" and modified natural cycle IVF for patients with expected poor response]
Unlabelled:
The aim of this study is to compare the efficiency of the "flare up" protocol (mini-dose GnRH-ag, macro-dose FSH, GnRH-ant, HCG)-gr. A, with a modified natural cycle IVF (GnRH-ant, HCG)-gr. B.
Results:
In gr. A 140 and in gr. B 17 patients were assessed. The average age is 35.5 in gr. A and 35 years in gr. B. The embryo transfer is realized 48-72 hours after ovarian puncture in 98 cases (70%) in gr. A and 11 cases (64.7%) in gr. B. Clinical pregnancy is registered in 32 cases (22.8% per cycle, 32.6% per transfer) in gr. A and 4 cases (23.5% per cycle, 36.3% per transfer) in gr. B. In gr. A the cancellation rate is 30%-42 cases and in gr. B--35.3%--6 cases.
Conclusion:
The preliminary results indicate that the 2 methods are equal as regards cancellation and success rate. The natural and modified natural cycle IVF have the following advantages: minimization of severe early and late complications and multifetal pregnancies as well as cost-effectiveness and better chance for pregnancy cumulation rate. There is no doubt that the "mild" and natural, resp. modified natural protocols will displace the conventional hyperstimulation regimens.
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