Day-5 fresh embryo transfer is associated with superior clinical outcomes in oocyte donation cycles compared with day-3 embryo transfer.

Objective: Τo compare clinical outcomes between day-5 (D5ET) and day-3 (D3ET) fresh embryo transfer in oocyte donation cycles.

Study Design: A retrospective analysis of prospectively collected cohort data was performed enrolling all participants in an oocyte donation program performed either D5ET or D3ET regarding the period from June 2006 to June 2018. Cycles were compared by the day of embryo transfer.

How does closed system vitrification of human oocytes affect the clinical outcome? A prospective, observational, cohort, noninferiority trial in an oocyte donation program.

Objective: To evaluate whether is possible to vitrify oocytes in an aseptic (hermetically closed) fashion and maintain clinical results comparable with those of fresh oocytes.

Design: Prospective, observational, cohort, noninferiority trial.

Setting: Private in vitro fertilization center.

History of endometriosis may adversely affect the outcome in menopausal recipients of sibling oocytes.

Due to the known adverse effect of endometriosis on gamete quality, it has always been difficult to demonstrate a direct effect of endometriosis on implantation. In order to eliminate these confounding effects, this prospective comparative study studied a population of menopausal recipients with and without endometriosis sharing sibling oocytes coming from the same donor. The aim was to understand the impact of endometriosis on implantation, pregnancy and live birth rates in menopausal recipients.

Cryptic sperm defects may be the cause for total fertilization failure in oocyte donor cycles.

In conventional IVF cycles with total fertilization failure, rescue intracytoplasmic sperm injection (ICSI) performed 24h after insemination has yielded poor results. However, when ICSI is used, total fertilization failure is a rare event. The aim of the present study is to investigate the degree of sperm contribution to fertilization failures using the egg-sharing model in oocyte donor cycles.

Double GnRH-antagonist dose before HCG administration may prevent OHSS in oocyte-donor cycles: a pilot study.

This pilot study evaluated the possibility of preventing early ovarian hyperstimulation syndrome (OHSS) by increasing the daily dose of gonadotrophin-releasing hormone (GnRH) antagonist administration (to twice a day) in oocyte-donor cycles stimulated with the antagonist protocol. The study included 72 oocyte donors who underwent ovarian stimulation using the GnRH antagonist protocol and might have had their cycle cancelled because of ovarian hyper-response. All women were donors presenting a rapid rise of oestradiol > or = 3000 pg/ml early in the stimulation period with more than 15 follicles of < or = 15 mm in diameter.

GnRH antagonists and endometrial receptivity in oocyte recipients: a prospective randomized trial.

The effect that gonadotrophin-releasing hormone (GnRH) antagonists exert on endometrial receptivity has not yet been elucidated. GnRH antagonists might directly affect oocytes, the embryo and/or the endometrium. The aim of this study was to investigate the direct effect of GnRH antagonists on the endometrium in oocyte donation cycles.

Low-dose human chorionic gonadotropin during the proliferative phase may adversely affect endometrial receptivity in oocyte recipients.

The effect of low-dose human chorionic gonadotropin (hCG) administration in the proliferative phase of oocyte recipients was investigated in a prospective randomized trial. Sibling oocytes from the same donor were shared at random among two different recipients. In group I oocyte recipients received 750 IU of hCG every three days concomitant to endometrial preparation with estradiol until hCG injection to the donor, whereas in group II recipients received no hCG during endometrial priming with estradiol.