Parameters that influence the results of in vitro fertilization/embryo transfer: a study of an egg donation model

A retrospective analysis was carried out after ovulation induction in donors, and treatment outcome in donors and recipients, relating to variables such as: age, protocol of ovarian stimulation, transfer of fresh or cryopreserved embryos, number of embryos transferred including quality and etiology of donor and recipient infertility. The recipients underwent 214 cycles of embryo transfer from 82 different donors. Forty-five (21%) pregnancies were recorded. The age of the recipients significantly affected the conception rate (pregnancy rate of 30% in those aged < 30 years, compared to 9.7% in those aged > 44 years) and the donors were contributed more to pregnancies were also younger. The pregnancy rate was significantly higher when fresh embryos were transferred to recipients (28%, compared to 15% when cryopreserved embryos were transferred). In addition, the number of embryos transferred affected the pregnancy rate if > or = 3 embryos were transferred and, if they were of good quality, the success was significantly higher. Ultimately, when the ovarian stimulation protocol was clomiphene citrate and human menopausal gonadotropin or gonadotropin-releasing hormone agonist/follicle-stimulating hormone/human menopausal gonadotropin, and the etiology of infertility was polycystic ovarian disease in the donors, the success rate was significantly increased in the recipients.