In vitro fertilization (IVF) is a complex series of procedures used to help with fertility or prevent genetic problems and assist with the conception of a child.

During IVF, mature eggs are collected (retrieved) from ovaries and fertilized by sperm in a lab. Then the fertilized egg (embryo) or eggs (embryos) are transferred to a uterus. One full cycle of IVF takes about three weeks. Sometimes these steps are split into different parts and the process can take longer.

IVF is the most effective form of assisted reproductive technology. The procedure can be done using a couple’s own eggs and sperm. Or IVF may involve eggs, sperm or embryos from a known or anonymous donor. In some cases, a gestational carrier — someone who has an embryo implanted in the uterus — might be used.

Your chances of having a healthy baby using IVF depend on many factors, such as your age and the cause of infertility. In addition, IVF can be time-consuming, expensive and invasive. If more than one embryo is transferred to the uterus, IVF can result in a pregnancy with more than one fetus (multiple pregnancy).

Your doctor can help you understand how IVF works, the potential risks and whether this method of treating infertility is right for you.

Why it’s done

In vitro fertilization (IVF) is a treatment for infertility or genetic problems. If IVF is performed to treat infertility, you and your partner might be able to try less-invasive treatment options before attempting IVF, including fertility drugs to increase production of eggs or intrauterine insemination — a procedure in which sperm are placed directly in the uterus near the time of ovulation.

Sometimes, IVF is offered as a primary treatment for infertility in women over age 40. IVF can also be done if you have certain health conditions. For example, IVF may be an option if you or your partner has:

• Fallopian tube damage or blockage. Fallopian tube damage or blockage makes it difficult for an egg to be fertilized or for an embryo to travel to the uterus.
• Ovulation disorders. If ovulation is infrequent or absent, fewer eggs are available for fertilization.
• Endometriosis. Endometriosis occurs when tissue similar to the lining of the uterus implants and grows outside of the uterus — often affecting the function of the ovaries, uterus and fallopian tubes.
• Uterine fibroids. Fibroids are benign tumors in the uterus. They are common in women in their 30s and 40s. Fibroids can interfere with implantation of the fertilized egg.
• Previous tubal sterilization or removal. Tubal ligation is a type of sterilization in which the fallopian tubes are cut or blocked to permanently prevent pregnancy. If you wish to conceive after tubal ligation, IVF may be an alternative to tubal ligation reversal surgery.
• Impaired sperm production or function. Below-average sperm concentration, weak movement of sperm (poor mobility), or abnormalities in sperm size and shape can make it difficult for sperm to fertilize an egg. If semen abnormalities are found, a visit to an infertility specialist might be needed to see if there are correctable problems or underlying health concerns.
• Unexplained infertility. Unexplained infertility means no cause of infertility has been found despite evaluation for common causes.
• A genetic disorder. If you or your partner is at risk of passing on a genetic disorder to your child, you may be candidates for preimplantation genetic testing — a procedure that involves IVF. After the eggs are harvested and fertilized, they’re screened for certain genetic problems, although not all genetic problems can be found. Embryos that don’t contain identified problems can be transferred to the uterus.

• Fertility preservation for cancer or other health conditions. If you’re about to start cancer treatment — such as radiation or chemotherapy — that could harm your fertility, IVF for fertility preservation may be an option. Women can have eggs harvested from their ovaries and frozen in an unfertilized state for later use. Or the eggs can be fertilized and frozen as embryos for future use.

  Women who don’t have a functional uterus or for whom pregnancy poses a serious health risk might choose IVF using another person to carry the pregnancy (gestational carrier). In this case, the woman’s eggs are fertilized with sperm, but the resulting embryos are placed in the gestational carrier’s uterus.

Risks

Risks of IVF include:

• Multiple births. IVF increases the risk of multiple births if more than one embryo is transferred to your uterus. A pregnancy with multiple fetuses carries a higher risk of early labor and low birth weight than pregnancy with a single fetus does.
• Premature delivery and low birth weight. Research suggests that IVF slightly increases the risk that the baby will be born early or with a low birth weight.

• Ovarian hyperstimulation syndrome. Use of injectable fertility drugs, such as human chorionic gonadotropin (HCG), to induce ovulation can cause ovarian hyperstimulation syndrome, in which your ovaries become swollen and painful.

  Symptoms typically last a week and include mild abdominal pain, bloating, nausea, vomiting and diarrhea. If you become pregnant, however, your symptoms might last several weeks. Rarely, it’s possible to develop a more severe form of ovarian hyperstimulation syndrome that can also cause rapid weight gain and shortness of breath.

• Miscarriage. The rate of miscarriage for women who conceive using IVF with fresh embryos is similar to that of women who conceive naturally — about 15% to 25% — but the rate increases with maternal age.
• Egg-retrieval procedure complications. Use of an aspirating needle to collect eggs could possibly cause bleeding, infection or damage to the bowel, bladder or a blood vessel. Risks are also associated with sedation and general anesthesia, if used.
• Ectopic pregnancy. About 2% to 5% of women who use IVF will have an ectopic pregnancy — when the fertilized egg implants outside the uterus, usually in a fallopian tube. The fertilized egg can’t survive outside the uterus, and there’s no way to continue the pregnancy.
• Birth defects. The age of the mother is the primary risk factor in the development of birth defects, no matter how the child is conceived. More research is needed to determine whether babies conceived using IVF might be at increased risk of certain birth defects.
• Cancer. Although some early studies suggested there may be a link between certain medications used to stimulate egg growth and the development of a specific type of ovarian tumor, more-recent studies do not support these findings. There does not appear to be a significantly increased risk of breast, endometrial, cervical or ovarian cancer after IVF.
• Stress. Use of IVF can be financially, physically and emotionally draining. Support from counselors, family and friends can help you and your partner through the ups and downs of infertility treatment.

How you prepare

The Centers for Disease Control and Prevention and the Society for Assisted Reproductive Technology provide information online about U.S. clinics’ individual pregnancy and live birth rates.

A clinic’s success rate depends on many factors. These include patients’ ages and medical issues, as well as the clinic’s treatment population and treatment approaches. Ask for detailed information about the costs associated with each step of the procedure.

Before beginning a cycle of IVF using your own eggs and sperm, you and your partner will likely need various screenings, including:

• Ovarian reserve testing. To determine the quantity and quality of your eggs, your doctor might test the concentration of follicle-stimulating hormone (FSH), estradiol (estrogen) and anti-mullerian hormone in your blood during the first few days of your menstrual cycle. Test results, often used together with an ultrasound of your ovaries, can help predict how your ovaries will respond to fertility medication.
• Semen analysis. If not done as part of your initial fertility evaluation, your doctor will conduct a semen analysis shortly before the start of an IVF treatment cycle.
• Infectious disease screening. You and your partner will both be screened for infectious diseases, including HIV.
• Practice (mock) embryo transfer. Your doctor might conduct a mock embryo transfer to determine the depth of your uterine cavity and the technique most likely to successfully place the embryos into your uterus.
• Uterine exam. Your doctor will examine the inside lining of the uterus before you start IVF. This might involve a sonohysterography — in which fluid is injected through the cervix into your uterus — and an ultrasound to create images of your uterine cavity. Or it might include a hysteroscopy — in which a thin, flexible, lighted telescope (hysteroscope) is inserted through your vagina and cervix into your uterus.

Before beginning a cycle of IVF, consider important questions, including:

• How many embryos will be transferred? The number of embryos transferred is typically based on age and number of eggs retrieved. Since the rate of implantation is lower for older women, more embryos are usually transferred — except for women using donor eggs or genetically tested embryos.

  Most doctors follow specific guidelines to prevent a higher order multiple pregnancy, such as triplets or more. In some countries, legislation limits the number of embryos that can be transferred. Make sure you and your doctor agree on the number of embryos that will be transferred before the transfer procedure.

• What will you do with any extra embryos? Extra embryos can be frozen and stored for future use for several years. Not all embryos will survive the freezing and thawing process, although most will.

  Having frozen embryos can make future cycles of IVF less expensive and less invasive. Or, you might be able to donate unused frozen embryos to another couple or a research facility. You might also choose to discard unused embryos.

• How will you handle a multiple pregnancy? If more than one embryo is transferred to your uterus, IVF can result in a multiple pregnancy — which poses health risks for you and your babies. In some cases, fetal reduction can be used to help a woman deliver fewer babies with lower health risks. Pursuing fetal reduction, however, is a major decision with ethical, emotional and psychological consequences.
• Have you considered the potential complications associated with using donor eggs, sperm or embryos, or a gestational carrier? A trained counselor with expertise in donor issues can help you understand the concerns, such as the legal rights of the donor. You may also need an attorney to file court papers to help you become legal parents of an implanted embryo.

What you can expect

IVF involves several steps — ovarian stimulation, egg retrieval, sperm retrieval, fertilization and embryo transfer. One cycle of IVF can take about two to three weeks. More than one cycle may be needed.