Introduction to IVF
I wrote this article as a sort of “IVF for beginners.” Even if you’ve been through IVF before, reading this may help you understand why we do what we do.
What is IVF? IVF is a type of treatment that involves taking eggs from a woman’s body, creating embryos with sperm and putting embryos into a woman’s uterus. That sounds kind of complicated, I know. I’m going to break it down in the simplest terms possible.
IVF stands for in vitro fertilization. It means fertilization outside of the body or in a controlled environment. In vitro = within the glass (in Latin).
Every woman has a set number of eggs that she can potentially ovulate every month. We ovulate 1 and the rest die. You can never use them again. Every woman’s “potential” number of eggs that she can ovulate declines as she ages. This number is different from woman to woman. For example a woman going through IVF at the age of 25 could have 30 eggs retrieved whereas a woman going through IVF at the age of 42 could have 4 eggs retrieved. How do you know what your potential number of eggs could possibly be? An ultrasound performed looking at your ovaries could tell you. The way we can assess your potential number is by looking at your ovaries and counting the number of antral follicles you have.
Antral follicles look like small black circles on your ovaries. Each black circle represents a fluid filled sac that contains 1 egg. Eggs are microscopic. We can’t see eggs on ultrasound. This is an example of an ultrasound image of an ovary. The black circles are antral follicles. The number of antral follicles that gives you a good chance of pregnancy with IVF is around 10 (both ovaries). Go to google images and enter the term “antral follicle.” You will see what I’m talking about.
When you take medications during an IVF cycle you are taking medications that will make the follicle size grow and the egg mature. The follicle size is a reflection of the maturity of the egg inside. We know that eggs tend to be mature when the follicle reaches close to 20 mm in size. We use millimeters when measuring follicles in the infertility world because a difference in 2 mm may make a difference in how we manage someone during an IVF cycle. Why do we care if an egg is mature or not? Only mature eggs can be fertilized by sperm.
The way I explain IVF to patients is this: IVF is a 6 week event in your life – from start to when you find out you’re pregnant. You take medications to quiet your ovaries, followed by medications to stimulate your ovaries followed by medications to support a pregnancy. The concept is this: you want to quiet the ovaries so that when you take stimulating medications you will be able to get as many eggs as possible followed by an egg retrieval procedure and an embryo transfer done days later. You need to take medications to support a pregnancy because the egg retrieval process removes cells that produce hormones like progesterone needed to support a pregnancy.
The medications we use to quiet the ovaries could be birth control pills or another form of hormonal suppression. Patients ask me all the time, “Why would you give me birth control pills when I’m trying to get pregnant?” Now you know why.
After about 2 weeks of birth control pills we then have patients take injections that go just below the skin for about 10 days. The length of time a woman takes medications all depends on the number of days required to get the most number of follicles to grow to about 20 mm.
The names of the injectable medications can be intimidating. You may hear gonadotropins used referring to the injectable medications. Gonadotropin hormones refer to the hormones FSH and LH. FSH=Follicle stimulating hormone. LH=Luteinizing hormone. Those are complicated terms! Now that you’ve learned these terms we make it even more complicated for patients by adding the brand names of the medications into the mix. For example, there are 3 different brands of FSH on the market: Gonal-F, Bravelle and Follistim. They are made by three different drug companies. There are 2 different LH products on the market: Menopur (combination of FSH and LH) and Luveris. You’re close to knowing everything there is to know about IVF.
Watch videos showing how the medications are mixed and administered by going to the following website: http://www.freedommedteach.com/player/Videos.aspx
Your doctor calculates a dose of medication that she thinks is right for you based on your age, antral follicle count and how you’ve responded to previous infertility treatments. She will then decide what type of medication to use to prevent ovulation.
I’ll write an article on the different types of IVF protocols another day.
So now that you’ve started your stimulating medications, your doctor will ask you to take a medication to prevent ovulation. There are a few medications that are on the market that we use for this reason: lupron, ganirelix and cetrotide. Ganirelix and cetrotide are in the same family of drugs called antagonists. Lupron and antagonists are taken at different times in an IVF cylce – your doctor will create a calendar for you telling you what to take when. Preventing ovulation is key because we want the eggs to be in the ovary when we go to retrieve them.
During the time of stimulation, expect to see your doctor for frequent ultrasound and blood draws to monitor how you’re doing on the medications. After about 10 days of stimulating medications, you will take a shot to trigger ovulation. Since you are taking a medication to prevent ovulation, the eggs will not leave the ovary. The shot that we use to trigger ovulation is actually pregnancy hormone. The egg retrieval is performed 36 hours after this shot is given.
The egg retrieval is a procedure that can be done in usually under 30 minutes. Most clinics do egg retrievals with an anesthesiologist present. Medications to help you fall asleep and treat pain will be given through an IV line placed in your arm. You will be breathing on your own but unconscious. When you wake up after the procedure you won’t have any memory of the procedure. Some clinics do retrievals under a lighter form of anesthesia so that you are awake. Find out ahead of time what your clinic does.
While asleep, you will be placed in stirrups much like the stirrups used during your pelvic ultrasounds. Your egg retrieval is just a pelvic ultrasound but during the ultrasound, your doctor will place a needle alongside the probe and under ultrasound guidance, will place the needle in the follicles of the ovary. The fluid in each of the follicles is then suctioned and goes directly into a test tube. Test tubes filled with follicular fluid are then handed to the embryologist who then examines the test tubes for eggs.
The eggs are then placed in Petri dishes and either injected with sperm (called ICSI=intracytoplasmic sperm injection) or inseminated with sperm. Inseminated with sperm refers to just placing a small droplet of sperm over the egg. Your doctor will decide which procedure is right for you.
Go to www.Youtube.com and enter the terms “egg retrieval” and you can see several videos showing how this procedure is done.
After your egg retrieval, the embryologist prepares your eggs so that they can be either injected or inseminated with sperm. The Petri dishes are then placed in an incubator. The day after your egg retrieval is when we know how many eggs have been fertilized. The embryos are then transferred 3-5 days after the egg retrieval. Your doctor will discuss with you whether you should have a transfer done – either 3 days or 5 days after the retrieval.
An embryo transfer is done like a PAP smear except a catheter loaded with your precious embryos will be passed through your cervix into your uterus. Most clinics will ask you to have a full bladder so that an ultrasound can be placed on your belly to allow the doctor to see exactly where the embryos are being transferred. You will then lie down for 30 minutes to let the embryos nuzzle into place. You will then check a pregnancy test about 2 weeks later to tell you if the embryos implanted or not.
I hope that reading this makes makes contemplating IVF less overwhelming. Many patients think that IVF involves long needles that get injected into the buttock. The good news is that you can now go through an IVF cycle without a single intramuscular injection. All injections are given in the skin of your tummy and are 5 mm long. Going through an IVF cycle is not easy but knowing what you are getting yourself into will make it easier.