In Vitro Fertilization - An Overview

For some couples, In Vitro Fertilization or IVF, will be necessary for conception. While these couples may not have ever anticipated needing IVF, it may dramatically increase their chances for conceiving. If the doctor is recommending IVF, you need to consider some things before conceiving.

Selecting a program

Before starting an IVF cycle, it is important to consider a few factors in selecting the clinic. First, you need to research SART statistics, made publicly available each year. In addition to looking at the pregnancy rates, you need to also look at the rates of multi-fetal pregnancies. While it may seem cute or easier to have twins or even triplets, your goal should be to have one healthy single pregnancy carried to term. The health risks posed to yourself and the embryos are increased when carrying multiples. Statistics are not the only thing you should look at before choosing a program. Is the staff friendly or helpful? Does the clinic seem well run? How long do you have to wait before seeing the doctor? Is it easy to get in touch with a nurse to ask questions? Are your phone calls returned? IVF can be an emotional and confusing process and it is extremely important to be able to get your questions answered in a timely manner.

Finally, is the clinic convenient to your house? Once you begin cycling, you will probably be asked to return to the clinic each day for monitoring. It is important that you are not commuting to the clinic for an hour, or late for work each morning as a result.

SART statistics

IVF Overview

While each program has different protocols for the medications, the overall process is the same. Normally, each month a woman’s body produces hormones to grow and mature an egg. Ovulation occurs when the eggs are mature in anticipation of fertilization and pregnancy. If pregnancy doesn’t occur, menses occurs and the cycle restarts. During IVF, medication is given to stimulate the ovaries to allow many eggs to grow and mature. Those eggs are removed surgically once mature and allowed to fertilize in the laboratory. Once the embryos grow in the lab for a few days, they are placed back into the uterus in the hopes they implant and cause a pregnancy.

Menstrual Cycle

Monitoring

Once you begin actively cycling, the doctor will probably ask you to return to the clinic on a daily basis for blood testing or ultrasounds. What are they looking for and how do they use that information to adjust the medication dosages? During each ultrasound, the technician will measure the uterine lining and the ovarian follicles. The uterine lining should thicken during the cycle in anticipation of pregnancy. Each ovary will be checked to see the size and progression of the ovarian follicles. Follicles are little sacs on the ovary which contain an egg. In response to stimulation by FSH, the follicles begin to grow. Once they reach a particular size, the eggs inside are considered mature and ready to be retrieved. Each clinic will have it’s own criteria for determining what that appropriate size is, although 16 mm seems to be average.

The blood tests measure different hormonal levels. Estradiol, a form of estrogen, will be measured to determine if the rate of increase is appropriate. It should rise by roughly 50% each day. If it is rising too quickly, or too slowly the medication dosages will need to be adjusted to produce that rise. Progesterone may also be measured to make sure ovulation has not occurred or is about to. If the progesterone level is above 3, ovulation is thought to have happened. Finally, LH or leutenizing hormone, may also be measured, as a sudden rise may indicate that ovulation is about to happen.

Medications

You will be taking various medicines when moving through an IVF cycle.

Suppressive: These medications helps prevent the body from doing what it’s meant to and ovulating once the the egg follicles begin to progress. If ovulation should occur, the cycle would be lost, as there is no way to retrieve them once that happens. Examples of suppressive medications include Lupron (leuprolide), Antagon (ganirelix acetate) and Microdose Lupron. Each medication is taken as a subcutaneous injection, meaning into the fatty tissue below the skin. Your doctor will direct you when and how to take these medications.

Lupron
Antagon

Stimulatory: Stimulatory medications cause the ovaries to grow all of the eggs that will eventually be retrieved. They are a combination of FSH, or Follicle Stimulating Hormone and LH, or Leutenizing Hormone, the hormones that the body makes naturally during the menstrual cycle. During IVF however, they are given in much higher, precise doses as determined by the doctor, typically for 10 to 12 days. These are also injectable medications and are given in a combination that the doctor feels is most appropriate for you. Examples include Bravelle (FSH), Menopur (FSH and LH), Gonal F (FSH), Luveris (LH), and Repronex. Dosing decisions are typically made based on the monitoring that occurs each day.

Giving a Subcutaneous (SQ) Injection
Bravelle
Menopur
Gonal-F
Luveris

Trigger: Once the doctor feels that you have reached the criteria to proceed to retrieval, he will order an injection of HCG or Human Chorionic Gonadotropin to finalize growth and maturation of the eggs. This injection is carefully timed so that retrieval will occur at the optimal time just before ovulation occurs. This injection can be given subcutaneously or intramuscularly, depending on how the doctor orders it for you.

Giving an Intramuscular (IM) Injection
HCG

Hormone Supplementation: After the retrieval, the doctor will probably place you on supplements of estrogen and progesterone to prepare the endometrial lining for implantation of an embryo. Each clinic has it’s own protocol, though progesterone in oil injections, progesterone suppositories or estrogen pills are commonly given.

Estrace
Progesterone

_Source:

Speroff, Leon; Glass, Robert; and Kase, Nathan. Clinical Gynecologic Endocrinology and Infertility: 6th Edition. Lippincott Williams and Wilkins: Philadelphia. 1999. p1133-1140.