What Is In Vitro Fertilization (IVF)?
What is it?
In vitro fertilization (IVF) is one of the most effective fertility treatments, as it can be done using your own gametes (eggs and sperm), donor gametes or embryos or even a gestational carrier. With IVF, eggs are removed from the ovaries and mixed with sperm in a laboratory culture dish (“in vitro” is Latin for “in glass”). In cases of poor sperm quality, the sperm are actually injected into the egg using a micromanipulation technology known as intracytoplasmic sperm injection (ICSI).
Who can benefit from IVF?
IVF is the safest and most effective option for managing all fertility problems, unless the primary problem is irregular ovulation, in which case simple ovulation-inducing medications can be used. Due to the lower cost and the absence of an egg harvesting procedure, superovulation with intrauterine insemination (IUI) is typically the first option for many couples. IUI treatment is effective, with 10 to 20 percent pregnancy rates. Depending on the specifics of the couple’s problem, IVF has a pregnancy rate of 30 to 50 percent per treatment for women under 36. In this age group, these success rates can be achieved with the transfer of a single embryo into the woman’s uterus.
“If a woman has irregular periods and is not ovulating, the best treatment for this fertility problem is to simply use medication to help the woman ovulate,” says Paul Claman, a reproductive-medicine specialist at the Ottawa Fertility Centre. “If there’s a sperm problem or if a Fallopian tube is damaged, the best option is IVF.” As well, if the woman suffers from endometriosis or unexplained fertility problems, if sperm are unable to survive in the cervical mucus or if there are antibodies that harm the sperm, specialists may recommend IVF as the best option.
IVF is not as effective for women who are in their late 30 to early 40s, says Claman, as the quality of eggs declines after the age of 35. Although sperm quality and quantity also decrease after the age of 40, Claman says that the change isn’t profound enough to make a big difference.
The procedure works best if the woman is in good health and at a healthy weight. “With women who are morbidly obese, it becomes technically difficult to retrieve the eggs,” says Claman. “Plus, there’s a high risk of life-threatening complications from pregnancy for the mother and baby in this patient group.” Underweight women who have a body mass index (BMI) of less than 18 risk developing serious complications later in pregnancy, such as fetal growth problems, otherwise known as intrauterine growth restriction. “We try to encourage underweight women to gain a bit of weight before starting fertility treatments so that they can have healthy children.”
What does the procedure involve?
One cycle of IVF takes between four and six weeks to complete. When preparing for IVF, women take self-administered injections of fertility medications called gonadotropins, also referred to as a follicle-stimulating hormone (FSH), daily. These are sometimes taken together with luteinizing hormone (LH). These medications stimulate the ovaries to release more mature eggs than usual. At the same time, these women take additional injections of medications called gonadotropin-releasing hormone (GnRH) agonists or antagonists daily to prevent early ovulation. Generally, patients give themselves two or three injections a day for 10 or more days. During this time of ovarian stimulation, patients visit the clinic two or three times for an ultrasound (and sometimes blood tests as well) to check on the development of their eggs. Once they are ready, a hormone called human chorionic gonadotropin (hCG), which acts as a surrogate for the natural ovulation-inducing LH surge, is taken to prepare for the eggs’ final maturation and retrieval. Thirty-six hours after the hCG injection, the eggs are retrieved.
“When they’re ready, we schedule a procedure in which an ultrasound probe is inserted into the vagina and a needle is guided alongside the probe into the ovary to collect the eggs,” says Claman. “It’s a five- to 10-minute procedure done under sedation.”
The woman’s partner provides a sperm sample and, if it’s normal sperm, the sample is prepared using a technology that provides the sperm with the ability to fertilize the egg outside of the body, known as sperm capacitation. If there are sperm problems, the sperm is prepared using a series of steps that prepares the sperm for injection into the egg using ICSI micromanipulation technology.
In cases where there are no problems with sperm quality, a sample of capacitated, moving sperm is added to each egg for fertilization to occur. If there are concerns that the sperm may have trouble fertilizing the egg, the sperm is injected into the egg using ICSI. Typically, there is a waiting period of two to five days before the embryos can be implanted. Allowing the embryos to grow as long as five days in the lab assists in choosing the most viable embryos for transfer into the uterus. Finally, the embryos are placed into the uterus using an embryo transfer catheter and guided through the cervix by ultrasound. Patients are advised to rest for about one hour after the procedure and then discharged. A few may even be able to return to work the next day.
Vaginal progesterone supplements are prescribed starting after the egg retrieval procedure and continuing up until the pregnancy test. The first pregnancy test will be taken 17 to 18 days after egg retrieval.
What are the risks?
The biggest risk of IVF is having multiples if more than one embryo is transferred into the uterus. “You might think ‘Well, it just means that she’ll be a busy mother and it isn’t really a risk,’” says Claman, “but the problem is that when you carry twins, there is a greater risk of serious complications during the pregnancy that could lead to children with lifelong disabilities.”
According to Claman, one in four twin pregnancies results in at least one of the babies spending the first two weeks of his life in intensive care. A less common complication of IVF is ovarian hyperstimulation syndrome (OHSS) from having a very large number of eggs mature from the fertility drugs, which can be life-threatening in extreme cases. Other risks include an increased chance of having an ectopic pregnancy or delivering a baby with a birth defect (but the risk is low, at about one to two percent).
Although Claman says there aren’t really any side effects to the fertility drugs—other than bloating from ovarian enlargement or OHSS—women often feel symptoms related to the challenge of going through the IVF process. “Any kind of emotionally challenging experience can create all kinds of physical sensations that aren’t pleasant,” he says. After the procedure, women usually feel bloated due to enlarged ovaries.
How successful is it?
The success rate of IVF depends on your age and particular fertility problems, but it’s quite a safe procedure. “For women who are in their 30s, particularly in their younger 30s, it’s a very effective treatment, even for the most severe fertility problems,” says Claman.