E2 given in late luteal phase can be extended beyond the onset of menses for a period of at least eight days before the start of the stimulation, allowing scheduling of stimulation in order to limit oocytes retrievals during weekends .

Administration of corifollitropin alfa, a Follicule stimulating Hormone (FSH) with extended release kinetics, seems particularly interesting for a synchronous recruitment of follicles after homogenization of the cohort.

The objective of this study is to evaluate the impact on the response to ovarian stimulation with corifollitropin alfa of E2 scheduling versus no scheduling for women over 38 years, age at which declining of ovarian reserve usually begins. The management of these patients in terms of organization of the center is also evaluated.

The scheduling of IVF cycles represents a double benefit. On one hand, to enable a "synchronization" of the follicular cohort for a best response and a higher number of mature oocytes. On the other hand, a more efficient organization for both the center (avoiding retrievals on weekends and public holidays, organize and distribute equally the activity, reduce cost operations) and couples (personal and professional organization).

With advanced age, ovarian reserve decreases, follicular cohort becomes heterogeneous under the influence of higher FSH rise in late luteal phase. It has been shown that estrogens (E2) taken in the late luteal phase homogenized follicular cohort by inhibiting inter cycle FSH peak ,and that this inhibition is immediately reversible after discontinuation of treatment .

E2 given in late luteal phase can also be extended beyond the onset of menses for a period of at least eight days before the start of the stimulation, allowing scheduling of stimulation in order to limit oocytes retrievals during weekends . A prospective randomized study comparing E2 scheduling and no scheduling has shown that there was no difference in birth rate in a population of normo-responders women . While in these patients, the number of oocytes was not different in the two arms, a recent pilot study founded a significant increase in the number of oocytes retrieved after E2 luteal phase priming compared to the absence of priming in a population of poor responders .

In 2013, a report of the French governmental BioMedicine Agency warned about the thrombo-embolic risk associated with the use of the contraceptive pill for IVF scheduling, especially in women over 35.

Administration of corifollitropin alfa, an FSH with extended release kinetics, seems particularly interesting for a synchronous recruitment of follicles after homogenization of the cohort. In the Pursue study, an equivalent efficacy has been shown with the daily administration of 300 IU FSH and corifollitropin alfa in patients over 35 years .

The objective of this study is to evaluate the impact of the response to ovarian stimulation with corifollitropin alfa of E2 scheduling versus no scheduling for women over 38 years, age at which declining of ovarian reserve usually begins. The management of these patients in terms of organization of the center is also evaluated.

The scheduling of IVF cycles represents a double benefit. On one hand, to enable a "synchronization" of the follicular cohort for a best response and a higher number of mature oocytes. On the other hand, a more efficient organization for both the center (avoiding retrievals on weekends and public holidays, organize and distribute equally the activity, reduce cost operations) and couples (personal and professional organization). This can be done with pills but there are controversial data on its impact on the chances of birth. It has been shown that estrogen scheduling provides opportunities for success equivalent to the absence of scheduling for patients with good prognosis . If this study confirms the initial hypothesis, it will show that a less favorable public can profit from the benefits of scheduling by estrogen on both the organization of the attempt and the chances of pregnancy through better ovarian response.

Inclusion Criteria:

• Patient of 38 years or more
• Planned in invitro fertilization or intracytoplasmic sperm injection rank 1 or 2 (rank = retrieval with transfer)
• With regular cycles from 26 to 35 days
• Weight > 50 kg and body mass index< or equal to 32
• Affiliation to the general system of French social security and reimbursement for fertility problems

Exclusion Criteria:

• Irregular cycles and/or polycystic ovarian syndrome
• Previous History of ovarian hyperstimulation syndrome
• Rank puncture > 2
• Uterine malformation
• Presence of hydrosalpinges
• Endometriosis stage III or IV