What Is In Vitro Fertilization?
In Vitro Fertilization is a high technology infertility treatment. Couples who have trouble conceiving, having failed to conceive for more than two years, often need to turn to a reproductive specialist who can evaluate and prepare them for this delicate procedure. With this procedure, most of the steps required to become pregnant are basically done outside the body in a specialized laboratory. The basic steps are as follows:
1. The ovary is stimulated to mature many egss. In a normal natural cycle, only one egg is matured an ovulated. With IVF, the goal is to have many, though not too many, eggs because the quality of eggs varies and we want to make sure we have at least one or two good quality eggs. The goal is not to have to repeat the IVF cycle again.
2. The ovary is evaluated by sequential ultrasound examinations to evaluate the response and measure the follicles. Follicles are what contain the eggs. They look like a black circle on ultrasound. The eggs are too small to be seen so we indirectly evaluate the egg by looking at the size of the follicle.
3. Once the follicles, that contain the eggs, are of appropriate size, indicating that the egg within is mature, the aspiration of the follicles is performed. This is a minor procedure whereby a needle is inserted through the vagina into the ovary under ultrasound guidance and the entire contest of the follicle, which includes the egg, is suctioned. Most clinics use some form of sedation for this because it can be painful. The eggs are aspirated into test tubes that the embryologist evaluates and isolates the eggs. These are then placed individually into petri dishes.
4. Sperm is either added to each egg (natural fertilization) or injected into each egg (ICSI) so that fertilization may occur. This will take 24 hours.
5. The eggs that fertilize are now placed into their individual petri dishes to allow for incubation. Incubation is done over a 3-5 day period. During this time, the fertilized egg will divide many times to evolve into a 6-8 cell embryo at 3 days or a blastocyst at 5 days. It's progress is monitored daily.
6. At 3 days from the retrieval or 5 days from the retrieval, the transfer is performed. The patient, with recommendations from the Physician, chooses which embryos to transfer and how many to transfer. These specific embryos are then isolated and placed into a very small and very flexible catheter in the embryology laboratory. The patient is placed into a transfer room, placed into the standard position for doing pap smears, and the cervix is prepared. The embryologist brings the embryo(s) into the transfer room and the Physician very gently slides the catheter into the uterus to a specific place. This location is verified by abdominal ultrasound examination. The embryo(s) is then deposited and the catheter gently and carefully removed. The embryologist will then take the catheter to the lab to verify that the embryo has not been re-aspirated.
7. The patient then takes medications to help support implantation of the embryo.
8. 8-12 days after the transfer, the pregnancy test is performed. If positive, we do pregnancy tests every-other day for four consecutive pregnancy tests. Since these tests measure the pregnancy hormone, BHCG, levels, we can see if the pregnany is progressing well by these four values.
9. If all goes well with the pregnancy tests, then the first ultrasound is scheduled in two weeks to confirm an intrauterine pregnancy and the number. This will be about 6 weeks gestational age based on the transfer date.
10. We then do a second ultrasound at 8 weeks gestation to verify a viable pregnancy.
At this point, the patient is then transferred to her Obstetrician to begin her prenatal care. For all infertility specialists this is a joyous occasion tempered by some sadness at not being able to follow the patient all the way through to delivery. When I began doing IVF, I was still practicing obstetrics and has the rare opportunity to deliver the babies that were conceived with our help. At this point in my practice career, I still do gynecology and I have much more time to focus on the infertility side of my practice as well. My patients benefit from still being able to receive gynecological advice as well as infertility advice.