In simplest terms, in vitro fertilization (IVF) is the process of fertilizing a woman’s egg outside of her body in a laboratory. Once fertilization occurs, the newly formed embryo is placed inside the mother’s uterus and allowed to follow its natural life course.
Studies have shown that the ideal candidates for in vitro fertilization include couples less than 35 years of age who have been trying to conceive for over a year but have been unsuccessful. Couples over 35 years of age who have been attempting to conceive, without success, for more than six months may also be ideal candidates. (Because increasing age leads to decreasing fertility, we don’t wait as long to start treatment in older women, because we don’t want to miss the window for a potential successful treatment.) The following causes of infertility may be treatable with in vitro fertilization:
- Ovulation disorders
- Damaged or blocked fallopian tubes
- Endometriosis
- Low sperm count
- Sperm immobility or other sperm problems
In vitro fertilization begins with ovulation induction. Fertility drugs (typically hormones) are prescribed to the woman to stimulate the production of multiple eggs. Ultrasound is used to monitor eggs as they develop, while hormone levels are checked through blood samples. After about 10 to 12 days, the eggs are ready to be removed. Immature eggs develop within fluid-filled sacs called egg follicles, which are present within a woman’s ovaries. Hormones influence the development of the follicles, and the fertility drugs taken for in vitro fertilization are the same hormones your body produces naturally.
A successful in vitro fertilization procedure depends on removing more than one mature egg. Using a method known as follicular aspiration, the physician guides a thin needle through the woman’s vagina into the ovary. During in vitro fertilization, suction is used to retrieve viable follicles so that multiple eggs can be fertilized. The process is non-invasive and is performed with monitored anesthesia care right in our offices. Patients are alert and comfortable after the procedure and typically recover for about 20 minutes before going home. Discomfort is often compared to that of menstrual cramping or abdominal tenderness and can be treated with Tylenol.
Following retrieval, the viable eggs are brought to the laboratory where they will be fertilized. Rather than the usual approach of just placing the sperm with the eggs in a dish and waiting to see whether fertilization will occur, we prefer to be proactive and ensure that the eggs are fertilized. Each egg is injected with an individual sperm from the patient’s husband, partner, or sperm donor, in a process known as IntraCytoplasmic Sperm Injection (ICSI). The healthiest sperm are chosen for this process. Fertilization is observed the following day by identification of two pronuclei (structures that look like craters on the moon). The embryos created will be allowed to continue growing in the laboratory for 5 days, or until the blastocyst stage.
During in vitro fertilization, one to two embryos are placed in the woman’s uterus at transfer. The actual number of embryos transferred to the woman’s uterus will depend upon the overall health of the embryos, the woman’s age, and the woman’s general risk level for multiple pregnancies.
Just prior to the embryo transfer, a small opening will be created in the egg membrane with a laser. This process – known as Assisted Hatching (AH) – helps the blastocyst(s) implant in the uterine lining and helps ensure successful in vitro fertilization.
The embryo transfer procedure is painless and requires no anesthetic. The selected embryos will be put in a small amount of nutrient media and transferred with ultrasound guidance through the cervix and into the uterine lining using a special catheter. Following the transfer, patients relax for about 15 minutes before they can get up and return to normal activity, with limited restrictions for heavy exercise and to abstain from intercourse for three days.