Biological therapy - FIV PDF Print E-mail

In vitro fertilization (IVF)

In vitro fertilization (IVF) is a procedure in which several mature oocytes (eggs) are collected and placed in a culture medium with a high number of motile sperm cells.

An in vitro fertilization cycle is comprised of the following steps:

  1. Hormone therapy to stimulate the ovaries and monitoring> : in a spontaneous cycle, normally a woman releases only one mature egg during each menstrual cycle.
    In order to significantly increase the chance of obtaining embryos, the ovaries are stimulated with hormones to increase the number of follicles with eggs that could be retrieved using follicular puncture.
    During the days of hormone administration, ultrasound and blood tests are carried out to monitor follicle growth and hormone levels (estradiol).
    The monitoring usually begins after a week of hormone therapy and is done almost daily, according to how each patient’s ovaries react.
    Monitoring is important in that it enables the clinician and biologist gauge follicle growth and determine the exact moment to stimulate egg maturation by hormonally triggering ovulation.

  2. Egg retrieval : during egg retrieval, a trans-vaginal ultrasound is performed to view the follicles. A fine needle guide attached to the vaginal probe permits to precisely and safely puncture each follicle.
    During puncture, follicular fluid is aspirated into a tube that is immediately taken to the laboratory.
    The follicular puncture procedure is not very long, around 15 minutes, and it is performed after analgesic administration in enough quantity to insure that the procedure is not painful.
    Follicular fluid is examined by embryologists in the laboratory using binocular magnifying glasses to collect the eggs within it.
    The eggs collected are then placed in an adapted culture medium and in incubators for maturation, simulating the natural conditions for fertilization in the Fallopian tubes.

  3. Egg insemination : collecting sperm cells and their preparation is usually done on the same day as egg retrieval, just before in vitro insemination.
    When frozen sperm is used, samples are prepared right before insemination.
    The prepared sperm cells are then placed in the culture boxes with the eggs for fifteen to seventeen hours.
    If the number of motile sperm cells is not high enough to obtain a reasonable chance of fertilization, intra-cytoplasmic injection of sperm cells into the egg is preferred to simple insemination of mature eggs.

  4. Fertilization and embryo evaluation : the day after in vitro insemination (IVF or ICSI), the inseminated eggs are observed to look for signs of normal fertilization.
    At this stage, the embryos have not begun their cellular division.
    Zygotes (normally fertilized eggs) remain in culture for at least one more day. At that time, the initial cell divisions must take place and an evaluation is then possible of the morphological quality of the embryos.

  5. The embryos can be transferred two (D2) or three (D3) days after insemination, and sometimes on D5 or D6 after insemination.
    The decision about which day of culture an embryo might be transformed, and the number of embryos to transfer, is made according to the patient’s age and medical history and the embryo’s evolution.
    With the patient’s consent, supernumerary embryos with good morphological quality will be cryopreserved.
    An embryo transfer is performed by placing the selected embryo or embryos in an adapted catheter that is placed in the uterus. It is a painless procedure that does not require the use of analgesics.
    Patients are asked to rest for a short period after the embryo transfer.
    Vaginal progesterone supplementation is given after egg retrieval to facilitate embryo implantation and to prepare the endometrium for pregnancy. It is continued until instructions are given after the first biological pregnancy test, 14 days after the embryo transfer.
    If the pregnancy test is positive, progesterone continues to be given for eight weeks, i.e. after the twelfth week of pregnancy (amenorrhea).
    An ultrasound is performed three to four weeks after the first positive biological pregnancy test to evaluate the number of gestational sac(s), as well as the initial embryonic development conditions.

For each of these steps, after being informed, prior written consent must be signed by both members of the couple.