What is involved in an IVF Cycle?
Many patients have heard of IVF (In vitro fertilization), and may even be facing IVF in their effort to conceive. However, many do not know exactly what is involved. This will hopefully give a quick overview of a typical IVF cycle.
The basic idea in IVF is to give the patient a large amount of gonadotropins (the hormones from the brain that stimulate egg development) to cause the development of many follicles (the ovarian cysts that each contain an egg). The hormones used must all be given as injections, as they do not come in pill form. The injections are given just under the skin like an insulin injection that a diabetic person might take. Once the follicles are fully developed, which usually takes 10-12 days of medication, the eggs are retrieved through an in-office procedure. The eggs are given to the embryology lab where they are fertilized with sperm, and allowed to grow for 3-5 days. At that point, the embryo(s) are transferred back into her uterus through a small catheter (tube).
There are several basic plans (protocols) for performing ovarian stimulation for IVF. There have been numerous variations reported over the years, but primarily two or three basic standard types have proven to be the most successful. The differences between any of the protocols are subtle. It is usually only through the judgment of the physician that it can be determined which protocol will be most suitable for a particular patient.
The two protocols that have been time-tested and most often used are termed “Agonist Protocols” and “Antagonist Protocols”. These terms refer to the type of medication that serves to prevent your body from trying to prematurely ovulate or release the developing eggs. In both protocols, the stimulation medication (FSH and LH) are used for a total of 10-12 days.
Though it may sound counterproductive, it is helpful to use a birth control pill for at least one cycle before starting the IVF medications. This serves to keep the ovaries quiet and prevent any cyst formation that may later interfere with the IVF cycle.
In an Agonist Protocol, a hormone (called a GnRH-agonist) is used to prevent the brain from trying to prematurely ovulating the developing follicles. This is usually started during the last week of the birth control pills, and continued daily up until the point of egg retrieval. The stimulation medications (FSH and LH) are started after being on the GnRH Agonist for approximately one week.
In an Antagonist Protocol, the stimulation medication is started once the menses following the birth control pill cycle occurs. After 4-6 days of stimulation medication, another hormone is started (a GnRH-antagonist), which prevents premature ovulation of the developing follicles. This is also continued until the point of egg retrieval.
The initial dose of medication is chosen by the physician based on several factors, including the patient’s age, previous IVF experience, and hormone levels. Usually the dosages of stimulation medications will be adjusted during the stimulation phase based on the results of close monitoring which includes a pelvic ultrasound and hormone measurements. This monitoring is performed at baseline before starting stimulation, and after the first 3-5 days of stimulation medications. From that point on, an ultrasound and estrogen blood level is usually performed every 2-3 days until the time of retrieval, for a total of 4-5 monitoring visits.
Once the majority of the ovarian follicles reach the proper size (usually 17-19 mm in diameter), a separate medication is given (hCG- human chorionic gonadotropin). This serves to “trigger” the eggs, causing the eggs to genetically awaken from their idle state, continue development, and become “mature” or able to be fertilized and develop into an embryo.
The hCG medication is given with specific timing. If the eggs are not retrieved, they would be ovulated and released. This timing is such that the egg retrieval occurs just several hours before the eggs would be released. The egg retrieval occurs in our certified operating room located within our office. Anesthesia medication is administered through an IV placed in an arm vein. This allows the patient to be fully relaxed and comfortable during the procedure. A pelvic ultrasound is performed as usual, and ultrasound guidance is used to guide a needle into each ovary allowing the fluid (containing the egg) in every follicle to be removed. After the eggs are carefully removed, they are given to the embryologist (the laboratory scientist specially trained in handling eggs and embryos). The entire retrieval usually takes about 15-30 minutes, and the patient goes home once fully recovered from the anesthesia (about 45 minutes later).
Fertilization and Embryo Culture
Once the eggs are retrieved, they are fertilized several hours later. This is usually done by mixing the eggs with the sperm. In cases of male fertility issues, an individual sperm may be directly injected into each egg. The fertilized eggs then start the process of dividing. They are grown (cultured) in a very closely monitored and controlled setting which allows for the optimal environment for the early embryos. They are assessed on the second day after retrieval, and depending on several factors, a decision will be made by the physician to either transfer the embryos on the following day (Day 3), or allow them to grow for an additional two days and transfer them on Day 5.
When the day comes for the embryo transfer, you will return to the office. The transfer will take place in another room specifically used for this purpose which is located next to the embryology lab. The transfer is a simple and painless procedure that does not require any type of anesthesia. It is very similar to having a pap smear performed. During the transfer procedure, a small catheter (tube) containing the embryos is carefully inserted through the cervix and into the uterine cavity. This is guided with an ultrasound to ensure that they are gently placed in the proper location. After the transfer, the patient relaxes for approximately 15 minutes then is able to go home. Once placed in the uterus, the embryos cannot “fall” out or dislodge.
After the Embryo Transfer
After the retrieval and transfer, hormone supplementation (using progesterone) is continued to provide extra support for the pregnancy. Progesterone is available in several forms including injection, vaginal tablets, and vaginal creams. A blood pregnancy test is performed about 14-16 days after the egg retrieval. Once a pregnancy test is positive, an ultrasound is performed approximately 3 weeks later, at which time we should be able to detect a heartbeat in the embryo. Progesterone is continued for an additional 2-3 weeks after the detection of a heartbeat.
At first glance, the steps of IVF appear very complicated. However, our entire team of physicians, nurses, and staff will work to guide you step-by-step through the entire process. Having a dedicated team available and on call 24-hours a day ensures that you have a continuous support network at your fingertips. The entire time-frame from the start of a birth control pill until the pregnancy test is approximately 7 weeks, during which specific IVF medications are used for 4 weeks. IVF is not necessary for every couple, but it is always the fastest route to a pregnancy.