Emergency IVF for embryo freezing to preserve female fertility: a French multicentre cohort study.
STUDY QUESTION
What are the outcomes of French emergency IVF procedures involving embryo freezing for fertility preservation before gonadotoxic treatment?


SUMMARY ANSWER
Pregnancy rates after emergency IVF, cryopreservation of embryos, storage, thawing and embryo transfer (embryo transfer), in the specific context of the preservation of female fertility, seem to be similar to those reported for infertile couples undergoing ART.


STUDY DESIGN, SIZE, DURATION
A French retrospective multicentre cohort study initiated by the GRECOT network-the French Study Group for Ovarian and Testicular Cryopreservation. We sent an e-mail survey to the 97 French centres performing the assisted reproduction technique in 2011, asking whether the centre performed emergency IVF and requesting information about the patients' characteristics, indications, IVF cycles and laboratory and follow-up data. The response rate was 53.6% (52/97).


PARTICIPANTS/MATERIALS, SETTING, METHODS
Fourteen French centres reported that they performed emergency IVF (56 cycles in total) before gonadotoxic treatment, between 1999 and July 2011, in 52 patients.


MAIN RESULTS AND THE ROLE OF CHANCE
The patients had a mean age of 28.9 ± 4.3 years, and a median length of relationship of 3 years (1 month-15 years). Emergency IVF was indicated for haematological cancer (42%), brain tumour (23%), sarcoma (3.8%), mesothelioma (n = 1) and bowel cancer (n = 1). Gynaecological problems accounted for 17% of indications. In 7.7% of cases, emergency IVF was performed for autoimmune diseases. Among the 52 patients concerned, 28% (n = 14) had undergone previous courses of chemotherapy before beginning controlled ovarian stimulation (COS). The initiation of gonadotoxic treatment had to be delayed in 34% of the patients (n = 19). In total, 56 cycles were initiated. The mean duration of stimulation was 11.2 ± 2.5 days, with a mean peak estradiol concentration on the day on which ovulation was triggered of 1640 ± 1028 pg/ml. Three cycles were cancelled due to ovarian hyperstimulation syndrome (n = 1), poor response (n = 1) and treatment error (n = 1). A mean of 8.2 ± 4.8 oocytes were retrieved, with 6.1 ± 4.2 mature oocytes and 4.4 ± 3.3 pronuclear-stage embryos per cycle. The mean number of embryos frozen per cycle was 4.2 ± 3.1. During follow-up, three patients died from the consequences of their disease. For the 49 surviving patients, 22.5% of the couples concerned (n = 11) requested embryo replacement. A total of 33 embryos were thawed with a post-thawing survival rate of 76%. Embryo replacement was finally performed for 10 couples with a total of 25 embryos transferred, leading to one biochemical pregnancy, one miscarriage and three live births. Clinical pregnancy rate and live birth per couple who wanted a pregnancy after cancer were, respectively, 36% (95% CI = 10.9-69.2%) and 27% (95% CI = 6.0-61%).


LIMITATIONS, REASONS FOR CAUTION
The overall response rate for clinics was 53.6%. Therefore, it is not only that patients may not have been included, but also that those that were included were biased towards the University sector with a response rate of 83% (25/30) for a small number of patients.


WIDER IMPLICATIONS OF THE FINDINGS
According to literature, malignant disease is a risk factor for a poor response to COS. However, patients having emergency IVF before gonadotoxic treatment have a reasonable chance of pregnancy after embryo replacement. Embryo freezing is a valuable approach that should be included among the strategies used to preserve fertility.


STUDY FUNDING/COMPETING INTEREST(S)
No external funding was sought for this study. None of the authors has any conflict of interest to declare.