Oocyte Reception

WHAT IS OOCYTE RECEPTION?

In an oocyte reception cycle, oocytes from a sperm donor of the recipient woman’s partner or from a sperm bank are fertilised in the laboratory and the resulting embryos are then transferred to the mother’s uterus

Currently, and mainly due to social changes, women delay reproductive sweating until later ages, decreasing the possibility of spontaneously conceiving with their own oocytes, which translates into a great increase in the demand for this technique. In patients with menstrual cycles, embryo transfer could be performed without complementary medical treatment if in most of these cases or in patients without ovarian function we administer a hormonal treatment that will allow us a better synchronization between the cycle of the donor and the recipient.

When is the Oocyte Reception indicated?

Recepción de ovocitos en mujeres con ciclo menstrual

  • Low ovarian reserve.
  • Endometriosis.
  • Altered Hormones
  • Insufficient response in IVF cycles
  • Repeated IVF failures
  • Repeated abortions with no treatable cause

Recepción de ovocitos en mujeres sin ciclo ovárico

  • Menopause
  • Early menopause
  • Iatrogenic menopause : (due to surgery or cancer treatments)
  • Primary ovarian failure (from birth): alteration in gamete endowment such as gonadal dysgenesis: Turner’s syndrome, Swyer’s syndrome, etc.

Requirements for performing an Oocyte Reception

A reception of oocytes can be carried out, as long as they comply with the following requirements:

Uterus

Presence of a uterus with the capacity to gestate

Health

Absence of maternal physical or mental illness that contraindicates hormonal treatment and/or gestation

Processes

  1. The patient receiving the oocytes, as well as her partner, once the medical indication for the technique has been given, must undergo a series of complementary examinations to evaluate her health status and confirm that the woman can carry out a gestation without risk to herself and/or her child (general analysis and serology, ultrasound scan and complete gynecological examination, among others).

  2. The reception of oocytes can take place in two contexts: after treatment of ovarian stimulation of a donor and later insemination of her oocytes, with simultaneous embryo transfer after cryopreservation of oocytes from previous donation. In patients with a menstrual cycle, the embryo transfer could be carried out without complementary medical treatment if in most of these cases or in patients without ovarian function we administer a hormonal treatment that will allow us a better synchronization between the cycle of the donor and the recipient. The aim of this treatment is to generate a favourable intrauterine environment for embryo implantation and, if gestation occurs, to maintain the initial stages of it until the placenta can assume this role.

  3. Endometrial preparation protocols include estrogens (tablets or patches), progesterone (vaginal ovuli or tablets) and sometimes other medications such as GnRH analogs. The guidelines are highly variable in terms of dose, duration, route of administration of the different drugs, but there does not seem to be any difference in terms of pregnancy rates. The follow-up of the recipient is sometimes carried out by means of ultrasound controls and hormonal determinations in the blood. In the laboratory, the donor’s oocytes are inseminated with the partner’s sperm or from the bank according to the indication in each case. This process can be carried out according to different techniques: Classic technique, in which oocytes and spermatozoa are sedimented in culture in a favourable medium for fertilisation Sperm microinjection (ICSI), in which a spermatozoon is injected into each matured and recovered oocyte

  4. The day after the insemination, the number of correctly fertilized oocytes that will potentially initiate cell division to become embryos can be determined. In some cases, the usual reproduction techniques can be complemented with other procedures on the gametes or embryos to improve the capacity of embryo implantation such as assisted hatching, extraction of fragments, etc. The transfer of the embryos can be carried out both on day 2 or 3 after obtaining the oocytes, and on day 4 or 5 (blastocyst phase embryo). Each cycle, the couple must agree with the medical team on the number of embryos to be transferred in an individualized way, in order to maximize the probability of gestation and minimize the risk of multiple gestation. Spanish law limits the number of embryos to be transferred in each cycle to 3, which consists of depositing the embryos into the uterus through the vagina and cervical canal. This procedure consists of depositing the embryos into the uterus through the vagina and cervical canal. It is an outpatient procedure, which does not require anesthesia.

  5. 10-14 days after the embryo transfer, a pregnancy test will be performed, usually a determination of the human hormone-hormone gonadotropin (ß-HCG) in the blood, to find out if gestation is present or not.

Oocyte Reception Results

Oocyte Reception is the assisted reproduction technique with the best results in gestation rates due to the use of oocytes from healthy patients under 35 years of age.

60%

Oocyte Reception