[Impact of donor parity on oocyte donation outcomes]

OBJECTIVES

Since 2015, in France, men and women who have never procreated are allowed to donate their gametes. This has led to an increase in the number of female oocyte donors, whereas there are many couples waiting for gametes that have a long waiting time. The aim of this study is to compare the results of donation with oocytes from nulliparous and non-nulliparous donors.

METHODS

Monocentric retrospective observational study (Lille University Hospital) between January 1st, 2016 and December 31st, 2019. Phenotypic characteristics and clinical and biological outcomes of oocytes donations were compared according to donor parity (nulliparous versus primiparous or multiparous).

RESULTS

One hundred and eighty-five donors (66 nulliparous and 119 non-nulliparous) were included in the study, allowing 284 ICSI cycles to be performed in recipient couples. On average, 11.5 oocytes were obtained per donation cycle, of which 7.8 were mature. In total, 4.6 mature oocytes were obtained per attempt and per recipient couple. Nulliparous donors are younger than non-nulliparous ones. An early pregnancy was obtained in 55.6% of the nulliparous donors and in 50.8% of the non-nulliparous donors (P=0.55). A progressive pregnancy was obtained in 49.2% of the nulliparous women and in 42.1% of the non-nulliparous women (P=0.36). There was therefore no difference in terms of early pregnancy and ongoing pregnancy whether the donation came from a nulliparous or non-nulliparous woman.

CONCLUSION

Donor parity does not seem to have an impact on the success of oocyte donation attempts.

Embryological Characteristics and Preimplantation Genetic Testing for Aneuploidy of Embryos Derived from Cryopreserved Oocytes of Women of Different Reproductive Ages

Oocyte vitrification is widely used for female fertility preservation. However, the efficacy of this procedure may depend on the women's age. The aim of the study was to compare the morphology, viability of cryopreserved oocytes, and their fertilization outcomes (fertilization, blastulation rate, level of embryo chromosomal aneuploidy-preimplantation genetic testing for aneuploidy [PGT-A]) in women of different reproductive ages. The studied oocytes were divided into groups depending on the age of patients: up to 30 years (group 1), 30-35 years (group 2), 36-40 years (group 3), and older than 40 years (group 4). It has been shown that in women of older reproductive age, the number of oocytes with polymorphism of endo- and extracytoplasmic structures was higher compared with younger patients. This could reflect on their cryosurvival rate, which was the highest in group 1 (98.1%) and the lowest was in group 4 (47.4%). With increasing age, the fertilization rate of cryopreserved oocytes and subsequent blastulation was decreased. However, the number of embryos with an aneuploid chromosome set number was increased. The chromosome set number euploidy rate of the embryos obtained from cryopreserved oocytes of advanced age women (group 4) did not differ from the fresh group with the same age (31.2% vs. 24.4%, p > 0.05), but the number of euploid embryos per patient was less than one (0.8 ± 0.1). Therefore, the decision to cryopreserve the oocytes of a patient of older reproductive age should be made individually for each situation, taking into account the prospects of obtaining full-fledged embryos and the chances of pregnancy.

Piezo-assisted ICSI improves fertilization and blastocyst development rates compared with conventional ICSI in women aged more than 35 years

PURPOSE

Piezo-assisted intracytoplasmic sperm injection (Piezo-ICSI) is reported to be an effective method for inseminating fragile oocytes compared with conventional ICSI (c-ICSI). However, infertile patient groups suitable for Piezo-ICSI have not been elucidated. This study was conducted to determine age groups suitable for Piezo-ICSI using sibling egg controls inseminated by a well-trained embryologist to reduce technical inequalities.

METHODS

A total of 947 matured oocytes were inseminated either by Piezo-ICSI or by c-ICSI in sibling oocytes as controls. Fertilization (2 pronuclei, PN), survival, and blastocyst development rates on day (D) 5 and D6 after insemination were compared between the Piezo-ICSI and c-ICSI groups. Further analyses were applied to groups of women >35 or ≤35 years of age.

RESULTS

There were no significant differences in fertilization, survival, or blastocyst development rates between the two insemination treatment groups. However, for women >35 years of age, the fertilization (P = .008) and blastocyst development (P = .016) rates with Piezo-ICSI on D5 and D6 were significantly higher than in those subjected to c-ICSI.

CONCLUSIONS

Piezo-ICSI was useful for inseminating oocytes from women >35 years of age.