In Vitro Fertilization (IVF)
Many patients believe that IVF is the most common treatment offered by reproductive endocrinologists for infertility. IVF is a major breakthrough that gives new hope to couples who otherwise could not produce genetically related children. However, most women become pregnant using less advanced technologies such as intrauterine insemination.
IVF is considered a first line treatment in selected conditions such as severe tubal disease, moderate to severe male factor, ovarian failure (using donor eggs) and some cases of endometriosis. It is also used after other therapies have failed.
IVF involves several steps beginning with the stimulation cycle. The ovaries must be stimulated to produce numerous eggs that can be retrieved and fertilized. Some eggs are damaged in the IVF process and enough must survive to produce an adequate number of embryos.
The female receives daily injections of follicle stimulating hormone (FSH) which stimulates the recruitment and development of multiple follicles, each containing one egg. Antagon is also given as an injection just prior to egg retrieval to prevent the body from prematurely releasing the eggs.
When Antagon cannot be given, Lupron is used to block the production of leutinizing hormone (LH). LH is the hormone that signals ovulation once the eggs reach maturity. Ovulation must be timed in an IVF cycle as a premature surge of LH can cause cycle cancellation. The use of Antagon or Lupron greatly reduces the cancellation risk.
FSH is administered subcutaneously in dosages determined by each patient’s protocol and her response. Patients come to our office for ultrasound monitoring and estradiol hormone level measurements while undergoing stimulation. These tests allow us to monitor follicular development and make necessary FSH dosage adjustments.
Once the physician determines that the eggs are mature retrieval is scheduled and human chorionic gonadotropin (hCG) is administered. hCG mimics the action of LH thus causing maturation of the eggs. They are removed just prior to release into your body.
Some women cannot produce eggs that will fertilize and develop due to age, genetic disease or other factors. In these cases, an egg donor can be used. Egg donors undergo the same stimulation and retrieval process. The eggs are fertilized with the partners’ sperm and the resultant embryos are transferred to the recipient mother.
On the day of retrieval the couple returns to our office. The male provides sperm by masturbation which is washed and specially prepared for exposure to the eggs. The female receives anesthesia in the minor procedure suite next door and the eggs are retrieved from the ovarian follicles using a small needle passed through the back of the vagina using ultrasound for visualization.
Once the eggs are retrieved they are passed to the embryologist who separates them from the follicular fluid. They are then placed in specially prepared media and combined with sperm in Petri dishes. Once fertilization occurs the embryos are kept in the incubator until the embryo transfer.
Micromanipulation procedures such as intracytoplasmic sperm injection (ICSI) are performed at this stage. When ICSI is used a single sperm is injected directly into the egg.
The embryos remain in the incubator until they mature, which is usually from 3 to 5 days. Embryos that survive to day 5 ( blastocysts) are heartier and more likely to implant and develop. Some embryos are lost during culturing so there must be enough embryos to “risk” extending the culture time to 5 days. Since blastocysts are more likely to survive, fewer can be placed in the uterus which reduces the risk of high order multiple births (>3). We use blastocysts wherever possible and make the decision on culture day 2 or 3 based upon the number of embryos, their quality, and other patient specific variables.
In many cases, couples produce more embryos than can be safely transferred back to the uterus in one cycle. These embryos can be cryopreserved for use in future non stimulated IVF cycles. The major advantage to process is that FSH injections are not necessary in the cryopreserved cycles therefore the cost is significantly less.
Some couples are at high risk for transmitting specific genetic diseases, such as Tay-Sachs. In these cases, the embryos may be screened using preimplantation genetic diagnosis (PGD) which allows us to identify embryos that carry the genetic abnormality.
The IVF nurse contacts the couple and advises when to arrive at our office for the embryo transfer. The embryos are placed in the uterus in a painless procedure using a small catheter and ultrasound for guidance. The patient is advised to rest for the next 24 hours and a pregnancy test is performed after approximately two weeks.
Success rates are influenced by many factors including the cause(s) of infertility and the female’s age. Rates also vary between different infertility treatment centers.