Controlled ovarian stimulation: The very first step to any of the ART processes is to induce the development of multiple follicles in the ovary rather than the single follicle that matures in a monthly natural cycle. Reproductive Endocrinologists agree that that chances for pregnancy are greater if more than one oocyte is fertilized and transferred to the uterus during the IVF cycle. Multiple follicular development is accomplished by administering supraphysiological doses of the hormones naturally produced during the cycle (follicle-stimulating hormone and luteinizing hormone). Today these hormones (Gonal F, FSH and Luveris, LH) are recombinant, produced in culture, and are very pure. Their subcutaneous mode of injection renders the daily administration of FSH and LH more tolerable than the previous generation of fertility medication.
The natural production of these hormones must be suppressed to prevent spontaneous ovulation prior to the oocyte retrieval. This is achieved through the use of Lupron prior to (on day 21 of the previous cycle) or Lupron or Cetrotide at the start of the start of the cycle (cycle day 2). This regimen allows us to control ovarian hyperstimulation and the timing of the follicular aspiration. In addition to suppressing specific pituitary function, Lupron also assists to synchronize the follicles and produce a better quality cohort for retrieval.
Ovarian stimulation is monitored through transvaginal ultrasound and frequent hormone evaluation. Estrogen production by the growing follicles as well as direct measurement by ultrasound guides our interpretation as to when we should trigger final maturation with hCG. The hCG simulates the patient’s natural LH surge responsible for the final pre-ovulatory changes in the oocytes, preparing them for fertilization. Even with pituitary down-regulation, spontaneous ovulation does occur, albeit rarely (3%). Thus some programs still monitor endogenous LH production throughout the stimulation cycle. To stimulate the final maturation of the oocytes in preparation for the retrieval, human chorionic gonadotropin (hCG, Profasi and Pregnyl) is administered ~ 36 hours prior to the oocyte retrieval.
Oocyte retrieval: Oocyte retrieval is accomplished by transvaginal guided aspiration. This is a minor surgical procedure that can be performed in a physician’s office under intravenous sedation, as the patient is asleep for such a brief period. The ultrasound locates the ovarian follicles and the distance from the vaginal ceiling. A guide attaches the retrieval needle directly to the ultrasound probe. In most instances the needle is passed through the vaginal wall during the aspiration. The follicular contents are examined in the laboratory and the oocytes separated from the fluid and cellular components. Laparoscopy has been described in the past as an alternate method for oocyte retrieval if the ovary is inaccessible through the vagina or even through the bladder. This procedure is used very infrequently. In more than 12 years and thousands of patients, this procedure has been employed only once at Crozer.
Culture and Fertilization: After the oocytes have been identified, they are rinsed and incubated until it is time for insemination, either by conventional methods or via intracytoplasmic sperm injection. During the time of the retrieval the male specimen is prepared for insemination in the Andrology Laboratory. Approximately 6-7 hours after the retrieval the purified highly motile fraction is added to the oocytes for conventional insemination. At a concentration of ~30,000 motile sperm/ 3 oocytes. The culture dishes are returned to the incubator until fertilization is assessed the following morning. Oocytes are assessed for evidence of fertilization at 15-18 hours post insemination and returned to the incubators until growth is assessed the following day.
Embryo transfer: The embryo transfer typically occurs 3 or 5 days after the oocyte retrieval. The procedure is performed in the clinic on an outpatient basis and no anesthesia or analgesia is used. The embryos are transferred to the uterus via a small catheter similar to that used during the mock transfer during your stimulation. The catheter is placed through the cervix into the endometrial cavity under ultrasound guidance. The embryo transfer is a quick procedure with essentially no discomfort. Patients remain in a reclined position in bed in our office for ~ 45 minutes after the procedure and are encouraged to resume normal activity the following day, with a few defined restrictions.