Read Our Bodies, Ourselves Online
Authors: Boston Women's Health Book Collective
Our Bodies, Ourselves (105 page)
Assisted reproductive technologies (ARTs) are procedures used to treat infertility in which both eggs and sperm are manipulated outside the body. ART procedures involve surgically removing eggs from a woman's ovaries, combining them with sperm in the laboratory, then returning the fertilized eggs or embryos to the woman's body or donating them to another woman.
The best-known ART is in vitro fertilization, also called IVF. In 1978, Britain's Louise Brown was the first baby born as the result of IVF. (The British physiologist Robert Edwards, who invented and carried out the procedure, was awarded the Nobel Prize in Physiology or Medicine in 2010.) Today approximately 1 percent of all children in the United States are born each year via ARTs such as IVF, egg donation, and surrogacy.
4
FERTILITY PRESERVATION AND EGG FREEZING
Unfortunately, many treatments for cancer can cause infertility. In an effort to preserve their ability to have children in the future, an increasing number of people are using techniques such as egg or sperm freezing before beginning cancer treatments. Research regarding how cancer affects reproductive health (also called oncofertility) and fertility preservation options are growing, sparked largely by the increase in the survival rates of cancer patients. For more detailed information about cancer and fertility preservation, see fertilehope.org.
One method for fertility preservation that has expanded beyond cancer patients is egg freezing. Some fertility clinics are promoting this option to all women interested in extending their fertility. The goal is to freeze your unfertilized eggs when you are in your twenties or thirties to use later in life when you are ready to build your family. However, this is still considered experimental as well as controversial. The American Society for Reproductive Medicine feels that there are not yet sufficient data to recommend the freezing of eggs for the sole purpose of circumventing reproductive aging in healthy women. The medications used to stimulate egg production carry health risks, and the high cost of egg freezingâabout $13,000 per cycleâputs it out of reach for many women. In addition, the high water content of eggs means that egg freezing is far more difficult and unpredictable than freezing sperm or embryos, and success rates are not yet clear. Some people fear that fertility clinics that promote expensive egg-freezing services are selling women false hope.
IVF is a multistep treatment process. Several weeks prior to the actual procedure, you will take hormonal contraception to suppress your own ovarian function. Following that you will receive one or a combination of fertility drugs, often by injection, to stimulate the production of eggs. During this time, you will have to make several visits to the clinic, where providers will carefully monitor the number and size of the eggs in each ovary.
Once the eggs are ready, the actual IVF procedure consists of two major steps: egg retrieval and embryo transfer. During the egg retrieval, you will be sedated while the mature eggs are surgically removed from your ovaries. This typically takes place at your local fertility clinic. Follicles from both your left and right ovaries are retrieved through a process called follicular aspiration. Follicular aspiration involves inserting a hollow needle through the cervix and into the ovaries. The needle is then used to suction out any follicles that may be present in the ovaries. In order to guide the needle into the appropriate area of the ovary, a transvaginal ultrasound will be used. Once the needle is in the proper position, any follicles inside the ovary will be aspirated out. The follicle aspirates will be immediately examined under a microscope to ensure the presence of viable eggs. This is different from the typical menstrual cycle, in which the ovaries process many eggs but only one mature egg is released into the tubes and can be fertilized.
After the egg retrieval process you may feel a little tender in your abdomen. You will also feel fatigued as a result of the anesthetic. After several hours of monitoring, you will be allowed to go home. You may notice some light vaginal spotting. You will also receive antibiotics to prevent infection.
After the retrieval process, your eggs will be joined with sperm from your partner or a donor in the lab. If the eggs are fertilized, they will be allowed to divide for three to five days, then placed back into yourâor a gestational carrier'sâuterus. This is called the embryo transfer. The embryo transfer catheter is loaded with the embryos and passed through the cervical opening up the middle of the uterus. An abdominal ultrasound is used simultaneously to view the catheter tip and ensure its proper placement. When the catheter tip reaches the ideal location, the embryos are released out of the catheter to the lining of the uterus. Again, this is different from the natural conception process, when typically the sperm meets only one egg in the tubes and after fertilization the one embryo falls into the uterus and implants in the uterine lining to establish a singleton pregnancy. Exceptions occur, and in about 2 percent of all natural pregnancies more than than one embryo grows in the uterus. However, because the norm is to transfer more than one embryo, in IVF more than 30 percent of the pregnancies are multiple.
For most women, the embryo transfer procedure feels similar to a Pap test and does not require any sedation or other drugs. You will likely feel no or minimal pain or discomfort.
About nine to eleven days after the transfer, a blood pregnancy test can be done. If one or more embryos have successfully implanted into the uterus, hCG hormone will be detectable.
If there are more viable embryos than are transferred, families may choose to freeze (cryopreserve) the extra embryos for future use. In addition to saving thousands of dollars in costs, this decision protects women from having to repeat stressful and potentially risky drug therapies to stimulate ovulation again. With recent technological advances, IVF cycles using frozen embryos have the same chance of success as those using fresh embryos.
The success rates of IVF vary greatly, based
on many factors, including the quality of the implanted embryos, the skill of the clinic, and, most important, a woman's age. On average, a woman younger than 35 who is using her own eggs and fresh embryos has about a 40 percent chance per cycle of getting pregnant and giving birth to a live baby. Women between the ages of 35 and 37 have about a 30 percent chance, women 38 to 40 about a 22 percent chance, and women 41 to 42 about a 12 percent chance.
5
In general, IVF costs about $10,000 to $15,000 per cycle. Insurance coverage for ART is patchy. Many employers, in an effort to contain costs, don't purchase such benefits for their employees. Some states have laws mandating that employers offer infertility treatment benefits. Medicaid does not cover ART, not even in states where by law employers must offer the benefits. To learn more about benefits you might be eligible for, check with your health care insurance plan. The infertility association Resolve keeps track of the states that mandate coverage of infertility treatment and describes the various laws. To find out more, see resolve.org/family-building-options/.
Intracytoplasmic sperm injection is a technique that involves injecting sperm directly into the middle of the egg. ICSI was originally developed for couples in which the male partner either has sperm that are unable to fertilize an egg or has very few sperm in his semen (as may happen after cancer treatment). In the most severe casesâwhen no sperm can be found in the man's semenâthe sperm can be surgically removed from the epididymis (the duct that houses immature sperm); the mature sperm are then injected into a woman's removed egg.
In most cases, about 50 to 80 percent of eggs injected using ICSI become fertilized, but the procedure itself might damage some eggs or the egg might not grow into an embryo even after it is injected with sperm. ICSI usually costs about $2,000 on top of the price for IVF. There are some concerns about the risks to babies conceived via ICSI, with some research suggesting that they have a higher-than-expected rate of birth impairments, including, in boys, infertility. Since ICSI is frequently used with men who have the poorest sperm quality, it is possible that genetic factors may play a role. Further research is needed to fully understand the risks.
ICSI increases the success rates of ART when male-factor infertility is present. However, national ART data do
not
show that using ICSI increases success rates when male-factor infertility is not present. Because there is no clear standard of care, clinics vary widely in their use of ICSI. Despite there being no clear evidence that it leads to better outcomes in the absence of male-factor infertility, more than 50 percent of IVF procedures in the United States are performed with ICSI.
Preimplantation genetic diagnosis (PGD) begins with the creation of an embryo using IVF. At its earliest state of development, one or two cells are removed from each embryoâsimilar to a biopsyâand are examined for genetic differences before the embryo is placed in the uterus to develop. PGD was originally developed for families with a history of genetic impairments, including Tay-Sachs disease, Down syndrome, cystic fibrosis, sickle-cell disease, spinal muscular dystrophy, Huntington's disease, Marfan syndrome, hemophilia, and fragile X syndrome. PGD is most often recommended when either parent is a known carrier or may be at risk of a genetic disability.
SINGLE-EMBRYO TRANSFERS
When reproductive medicine was in its infancy, many fertility clinics transferred multiple embryos during each cycle, attempting to increase the rate of pregnancy. This technique resulted in many twin, triple, and even higher-order multiple births. Unfortunately, multiple birthsâincluding twin birthsâgreatly increase the chances that a woman and her children will have poor health outcomes.
The most common problems in the short term are that multiples are often preterm and the babies often have a low birth weight. Preemies are more likely to need intensive care and longer stays at the hospital and are at higher risk of dying shortly after birth. Birth impairments are also more common among multiples, although they affect a minority of the infants. The longer-term consequences of preterm delivery and low birth weight include developmental disabilities such as cerebral palsy (CP). Whereas the rate of CP is about 2 percent among singletons, some studies have found that the rate is about five times as high among twins and about twenty times as high among high-order multiples. These risks are not limited to multiple births: babies that are born singletons but were part of a multiple pregnancy have some of them as well. Multiple pregnancies also carry a higher risk of health complications for the mother during pregnancy and birth.
And there are effects on the health of the family as well: studies show that divorce is much more common among couples that have had multiples than among couples who have had singletons. Finally, there are consequences for society at large, because the costs of the medical care for multiple pregnancies and infants born in multiple births are huge compared to the costs associated with caring for singletons.
Because of these risks, many experts in the field now encourage the strategy of transferring only one embryo at a time. A 2010 meta-analysis of clinical trials comparing the outcomes of double embryo transfers with the outcomes of a sequence of one single-embryo transfer followed by a thawed embryo transfer if the first cycle has not succeeded found single-embryo transfer more likely to lead to the birth of a single, healthy baby.
6
Though the first strategyâdouble-embryo transferâleads to pregnancy faster, it is associated with multiple births and the related adverse health outcomes. The second strategyâsingle-embryo transferâmay require more attempts but almost invariably yields singleton births and better health outcomes for both mother and baby. The chance of a woman giving birth to a single full-term baby (over thirty-seven weeks) following single-embryo transfer is almost five times greater than her chance of doing so following double-embryo transfer.
The main barrier to elective single-embryo transfers is cost. Many families are unable to pay for multiple IVF cycles, so they opt to have multiple embryos transferred in a single cycle. The first insurance company to address this problem, Aetna, recently marketed a benefit that offers a free “rescue” IVF cycle to women who choose elective single-embryo transfer if the first cycle fails.
CLINIC STATISTICS AND SUCCESS RATES
Success rates for ART vary greatly, as many factors affect them, including the kind of procedure performed, the health and age of the individuals involved, and the skill and experience of the clinic. The Centers for Disease Control and Prevention (cdc.gov/art) and the Society for Assisted Reproductive Technology (sart.com) gather and publish yearly statistics on the success rates of various procedures. Though all IVF clinics are required by law to report their data to the CDC each year and about 85 to 90 percent do so, the only penalty for clinics that don't is that the CDC publishes their names as “nonreporters.”
The CDC warns against using just the report to rank clinics, because despite the standard format, differences in success rates are tricky to interpret. Still, the numbers give you a place to start and contain some important information that can help you evaluate fertility clinics. It is important to ask several questions as you view infertility statistics:
⢠How is “success” defined? Success can be defined many different waysâby the number of embryo transfers, the number of pregnancies, or of births. What you are interested in is the live birth rate (preferably single births) among women of your age and diagnosis using the same treatment you are undergoing.
⢠Are there parameters excluding certain women from the clinic? Some clinics may refuse to take on particular women, such as women above a certain age or women who are unlikely to conceive, in the hope of bumping up their statistics. Pay careful attention to the ages, diagnoses, and other characteristics of the patients the clinic routinely treats. Select one that has had good success with patients like you.
⢠What is the average number of embryos transferred per IVF cycle? What is the singleton live-birth rate? Responsible ART programs try to maximize their pregnancy rates while minimizing the multiple-pregnancy rate. Needing to transfer too many embryos may indicate suboptimal laboratory conditions or a less refined embryo transfer technique.
⢠Does the clinic offer elective single-embryo transfer (e-SET)? What is its live-birth rates after e-SET?
⢠What are the frozen embryo pregnancy and birth rates? In order to maximize the number of pregnancies that can be achieved from a single egg retrieval (and lessen your need to take additional fertility medications), it's important to assess your clinic's experience with frozen embryos. Increased pregnancy rates from frozen embryo transfers are also an indirect indication of a high-quality laboratory and transfer procedures.
⢠Numbers count! If a clinic performs only a few ART cycles every year, all of its measures of success will be statistically imprecise, and a high (or low) success rate may be that way because of chance rather than skill. Choose a clinic that has a high success rate based on large numbers of cycles.
For more information about IVF clinic statistics, see the CDC's video “Infertility: A Tutorial on the ART Report” (cdc.gov/art/PreparingForART/) or read its fact sheet at cdc.gov/art/PreparingForART/Tutorial.htm.
