Effect of ovarian stimulation and oocyte retrieval on reproductive outcome in oocyte donors

Planned oocyte cryopreservation: the state of the ART

The objective of this review is to provide an update on planned oocyte cryopreservation. This fertility preservation method increases reproductive autonomy by allowing women to postpone childbearing whilst maintaining the option of having a biological child. Oocyte cryopreservation is no longer considered experimental, and its use has increased dramatically in recent years as more women delay childbearing for personal, professional and financial reasons. Despite increased usage, most patients who have undergone oocyte cryopreservation have not yet warmed their oocytes. Most women who cryopreserve oocytes wait years to use them, and many never use them. Studies have demonstrated that oocyte cryopreservation results in live birth rates comparable with IVF treatment using fresh oocytes, and does not pose additional safety risks to offspring. Based on current evidence, cryopreserving ≥20 mature oocytes at <38 years of age provides a 70% chance of one live birth. However, larger studies from a variety of geographic locations and centre types are needed to confirm these findings. Additional research is also needed to determine the recommended age for oocyte cryopreservation, recommended number of oocytes to cryopreserve, return and discard/non-use rates, cost-effectiveness, and how best to distribute accurate and up-to-date information to potential patients.

[Fertility preservation in women of the childbearing age: Indications and strategies]

Advances on cryopreservation techniques now allow considering oocyte, embryo or ovarian tissue freezing for female fertility preservation. Originally developed for patients suffering from cancer, fertility preservation has rapidly invaded others medical fields, and represents now the standard of care for all young patient diagnosed with a disease that could impair fertility or having to receive possibly gonadotoxic treatment. As a result, autoimmune diseases, some genetic pathologies or iterative pelvic surgeries, at risk of premature ovarian failure, have become common indications of fertility preservation. In addition, the social egg freezing aiming at preventing the age-related fertility decline is still debated in France, although authorized in numerous countries. This review will discuss the different strategies of fertility preservation in young girls and women of reproductive age, regarding different medical or non-medical indications.

Fertility preservation for age-related fertility decline

Cryopreservation of eggs or ovarian tissue to preserve fertility for patients with cancer has been studied since 1994 with R G Gosden's paper describing restoration of fertility in oophorectomised sheep, and for decades previously by others in smaller mammals. Clinically this approach has shown great success. Many healthy children have been born from eggs cryopreserved with the Kuwayama egg vitrification technique for non-medical (social) indications, but until now very few patients with cancer have achieved pregnancy with cryopreserved eggs. Often, oncologists do not wish to delay cancer treatment while the patient goes through multiple ovarian stimulation cycles to retrieve eggs, and the patient can only start using the oocytes after full recovery from cancer. Ovarian stimulation and egg retrieval is not a barrier for patients without cancer who wish to delay childbearing, which makes oocyte cryopreservation increasingly popular to overcome an age-related decline in fertility. Cryopreservation of ovarian tissue is an option if egg cryopreservation is ruled out. More than 35 babies have been born so far with cryopreserved ovarian tissue in patients with cancer who have had a complete return of hormonal function, and fertility to baseline. Both egg and ovarian tissue cryopreservation might be ready for application to the preservation of fertility not only in patients with cancer but also in countering the increasing incidence of age-related decline in female fertility.

Pregnancy outcome of non-anonymous oocyte donation: a case-control study

OBJECTIVE

To evaluate the maternal and neonatal outcome of non-anonymous oocyte donation compared to in vitro fertilization. Study design We compared 84 oocyte donation pregnancies with a 251 matched in vitro fertilization cohort. Maternal and neonatal outcomes were retrieved from a nationwide perinatal registry. Oocyte donation and in vitro fertilization pregnancies were matched for maternal age, study center, ZIP code and embryo transfer date. Both maternal and neonatal complications and outcome were compared between oocyte donation and in vitro fertilization with univariate and multivariate logistic regression analyses, adjusting for maternal age, donor age, socio-economic status, ethnicity, and parity.

RESULTS

In total, 277 women underwent 541 oocyte donation cycles. The median recipient age was 34.9 years (IQR: 31.5-38.5), while the median donor age was 34.4 years (IQR: 31.7-37.0). Clinical pregnancy rate was 26.6%, which is comparable to standard in vitro fertilization treatment. Donor age in years (OR 0.93, 95% CI 0.88-0.99) and a previous pregnancy of the recipient (OR 1.69, 95% CI 1.02-2.78) were significantly associated with clinical pregnancy rate. Both singleton and multiple oocyte donation pregnancies were associated with pregnancy-induced hypertension compared with in vitro fertilization singleton and multiple pregnancies (OR 1.99, 95%CI 1.02-3.89, OR 6.43, 95% CI 1.67-24.72, respectively). No significant differences in neonatal outcome were observed.

CONCLUSION

Oocyte donation pregnancies are associated with an increased incidence of pregnancy-induced hypertension compared with age-matched in vitro fertilization controls. However, no significant differences in neonatal outcome were observed between oocyte donation and in vitro fertilization.