The study has a multicentric, parallel group, comparative, non-interventional, exploratory and prospective design.
Definition of isthmocele: defined as a dehiscence of the hysterotomy following a caesarean section. The residual myometrial thickness is less than 3mm, measured in the sagittal plane by hysterosonography.
The presence or absence of an isthmocele according to this definition will allow for the distribution of patients into one of two study groups : "isthmocele +" or "isthmocele -".
Definition of clinical pregnancy rate: defined as the presence of an intrauterine gestational sac and an embryo with cardiac activity visualized during an ultrasound examination at 7 weeks after embryo transfer.
Methods : During the initial ART consultation, the study is presented (oral information and distribution of a brochure) to patients consulting for infertility and with a history of cesarean section. It is during this consultation that the ART treatment assessment (blood tests and imaging: ultrasound and hysterosonography) is prescribed. If they agree to take part in the study, the non-opposition of eligible patients is collected during this consultation (pre-inclusion). Furthermore, among patients who agreed to participate in the study, socio-demographic data and the couple's medical history are collected during this initial consultation.
For patients who agreed to participate in the study, a specific measurement is made during the hysterosonography examination in order to determine the presence or absence of an isthmocele. Inclusion in the study is validated after a successful hysterosonography examination that confirms the presence or absence of an isthmocele. The patients are then attributed either to the: "isthmocele +" group or "isthmocele -" group.
During the second ART consultation, the results of the treatment assessment are collected, in particular the presence or absence of an isthmocele on the hysterosonography examination.
Subsequently, the data relative to ovarian stimulation, the methods of triggering and embryo transfer are collected prospectively by the investigator or co-investigators.
As part of the standard ART treatment, blood HCG tests are carried out 14 days after embryo transfer in order to detect a possible pregnancy. If the blood HCG levels are positive, the test is repeated 48 hours later and again a week later to survey the evolution of the blood HCG levels. At 6 to 7 weeks after oocyte puncture, an ultrasound scan is performed in the ART department if the blood HCGs level is greater than 10 IU/L with a satisfactory evolution after 48 hours. This data is collected for research purposes.
In the case of pregnancy and delivery in the same hospital as the ART treatment, obstetrical data is collected by the investigators or co-investigators from the obstetrical file. In the case of delivery at another facility, patients were contacted by telephone one year after a positive pregnancy test (HCG).
Discussion: No individual benefit is expected from this study since the management of the patients included corresponds to standard practice.
Concerning the collective benefits, if the conclusions of this study allow for the confirmation of our hypothesis (reduction in the pregnancy rate in the presence of a significant isthmocele), this could lead to a change in clinical practices in patients treated with ART. Indeed, surgical management of the isthmocele could be discussed prior to ART by informing the patient of the benefit-risk balance of the operation.
If our hypothesis of reduced fertility in the presence of isthmoceles is confirmed, further studies should ideally be carried out in order to demonstrate that the surgical management of isthmoceles improves the results of ART before systematically offering surgery to patients.
Trial Registration : The research protocole has been approuved by the relevant French authorities Comité de Protection des Personnes Sud Méditerranée IV on the 10th of November 2020 and recorded prospectively (before the inscription of the first participant) under the number ID-RCB : 2020-A02068-31.
