Duostim: a paradigm shift in in vitro fertilization

Duostim: a very important paradigm shift in in vitro fertilization

Duostim is a new strategy in in vitro fertilization (IVF) that involves performing two ovarian stimulations within a single menstrual cycle, instead of one. This allows for two follicular aspirations to be performed within about 30 days. The method aims to increase the number of mature oocytes (eggs) available for fertilization and thus increase the chances of success in IVF. 

Contrary to the initial belief that only one dominant follicle could be recruited per natural menstrual cycle to produce a mature egg, we now know that within the same menstrual cycle, there can be two to three waves of follicular recruitment. The principle of Duostim is therefore based on this new scientific finding.

Two ovarian stimulations

Specifically, Duostim involves performing a first ovarian stimulation in the follicular (proliferative) phase with gonadotropins to retrieve a first batch of oocytes, followed immediately, five days after the first oocyte retrieval, by a second ovarian stimulation in the luteal (secretory) phase, all within the same menstrual cycle. This allows for a second batch of oocytes to be quickly retrieved. All the mature oocytes collected are usually fertilized in the laboratory. The resulting high-quality blastocyst (5 to 6 days of life) stage embryos are frozen and then transferred to the patient’s uterus during a subsequent, more natural menstrual cycle. 

Duostim increases the chances of success in IVF

Duostim is mainly indicated for infertile women with low ovarian reserve or decreased oocyte quality, as well as for older women with reduced success rates in traditional IVF due to their age. This technique increases the number of mature oocytes available for fertilization and thus increases the chances of success in IVF. It can also be used to quickly preserve fertility in women who wish to freeze their eggs, whether before chemotherapy in cancer patients, for example, or for social purposes, particularly for career women who are not yet ready to start a family. 

Success rates and advantages of Duostim

Success rates for Duostim vary depending on the patient’s age and oocyte quality. Studies confirm success rates higher than those obtained in traditional IVF. The advantages of Duostim are multiple. 


– allows for a larger number of mature oocytes to be obtained in a very short period of time (usually within about 30 days)

– increases the overall chances of IVF success compared to a single traditional IVF cycle

– reduces the costs associated with IVF by performing two stimulation cycles and two oocyte retrievals within a single menstrual cycle, and limits the time between stimulation cycles, which is important psychologically, particularly in older women who are concerned about the rapid decrease in their ovarian reserve. 

Independent international studies have highlighted the consistency and reproducibility of this approach, which significantly reduces dropouts between consecutive IVF cycle failures. 

Duostim and Fertilys’ data

Fertilys has been offering Duostim for over 6 months now. Our own data confirm its effectiveness in patients who had a poor prognosis due to low ovarian reserve, most often following previous failures in traditional IVF. In the first phase of Duostim, Fertilys obtained an average of 4 oocytes, and 6 in the second phase. The embryo freezing rate was 57% in the first phase of Duostim and 59% in the second phase. Seventy-six percent (76%) of these patients, despite having a poor prognosis, ended their first trial of Duostim with at least one frozen blastocyst, with an average of 2 and 3 frozen blastocysts in phase 1 and 2, respectively, for average total of 5 blastocysts frozen per Duostim.

Does Duostim apply to you?

In conclusion, results are very encouraging. However, every case is different. It is therefore important to discuss with your doctor the benefits and risks of Duostim and determine whether or not it applies to you.

Blog article written by Cheng Wei Xiao MD in collaboration with Debbie Montjean PhD and Pierre Miron MD PhD.

Publish on: March 5 2023 in Préservation de la fertilité | Procréation | Fécondation in vitro | Infertilité | Infertilité | Stimulation ovarienne | Fécondation in vitro | Stimulation ovarienne

Dre. Cheng Wei Xiao
By: Dre. Cheng Wei Xiao MD, FRCSC, Fertologue, Gynecologist

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