Infertility is a complex condition with many possible causes and a number of different treatments. In vitro fertilization, or IVF, is one option for treating infertility. The in vitro fertilization definition is an artificial living environment outside a living body. Literally translated from Latin, “in vitro” means “in glass,” which refers to the petri dish or test tube in which one or more eggs are fertilized before being implanted in a woman’s uterus.

In vitro fertilization isn’t generally the first intervention used for couples with infertility. Before you get to IVF, you’ll probably work with your doctor to exhaust other options for conceiving. These may include making lifestyle changes, taking fertility drugs to promote egg production, or undergoing intrauterine insemination, which involves placing sperm directly in the uterus around the time of ovulation.

In Vitro Fertilization Definition

When is In Vitro Fertilization Used? 

In vitro fertilization is the most effective treatment for infertility, with per-cycle success rates around 20 to 40 percent. IVF is invasive, time-consuming, and expensive, but for couples who are ready to start a family but can’t conceive on their own, IVF is more than worth the trouble and expense.

Many conditions can prevent a couple from conceiving naturally. IVF is a possible option for conditions like:

  • Ovulation disorders. If you ovulate infrequently or not at all, eggs are not released for fertilization.
  • Damaged or blocked fallopian tubes. Blockages or damage to the fallopian tubes can prevent eggs from being fertilized or the embryo from traveling to the uterus.
  • Premature ovarian failure. If you’re under 40 and your ovaries don’t produce enough estrogen or release eggs regularly, you may have premature ovarian failure.
  • Uterine fibroids. These benign tumors grow in the wall of the uterus and can prevent implantation of a fertilized egg.
  • Endometriosis occurs when uterine tissue grows outside of the uterus and affects the function of the fallopian tubes, uterus, and ovaries.
  • Tubal sterilization. If you’ve had a tubal ligation, IVF makes it possible to conceive again without having to undergo a tubal ligation reversal.
  • Sperm problems. Impaired sperm production or poor sperm motility, or movement, can make natural fertilization difficult.
  • Genetic disorders. IVF allows couples to reduce the risk of passing on a genetic disorder to their child. The eggs are collected, fertilized, and screened for genetic problems, although all genetic disorders can’t be identified. Embryos without identified problems are then transferred to the uterus.
  • Unexplained fertility. Sometimes, a cause of fertility can’t be identified. In these cases, IVF may be an option.
  • Before undergoing chemotherapy or radiation treatments for cancer, which could reduce fertility, you may choose to have healthy eggs collected from your ovaries and frozen, fertilized or unfertilized, for IVF use later on.

Women who are at risk of serious health problems due to pregnancy or those who don’t have a functional uterus can choose IVF using another woman to carry the pregnancy, known as a gestational carrier.

Pre-In Vitro Fertilization Screenings 

Before undergoing in vitro fertilization, couples undergo a variety of screenings. These include:

  • Uterine cavity exam. To ensure your uterus can support a pregnancy, your doctor will examine it using an ultrasound or a hysteroscope, a thin, flexible telescope inserted into your uterus through your vagina.
  • Infectious disease tests. Testing for HIV and other infectious diseases before IVF ensures a clean bill of health before becoming pregnant.
  • Semen analysis. A semen analysis will provide your doctor with information about the semen’s quality, quantity, and motility to help ensure successful fertilization.
  • Ovarian reserve analysis. To help predetermine your ovaries’ response to fertility medication and assess the quality and quantity of eggs, your doctor may test the amount of follicle-stimulating hormone (FSH) in your blood at the beginning of your menstrual cycle.
  • Mock embryo transfer. Before undergoing IVF, your doctor may conduct a trial run in order to determine the best technique to use, depending on the depth of your uterine cavity.

Risks of In Vitro Fertilization 

In vitro fertilization doesn’t come without risks, both in the procedure itself and the resulting pregnancy. The most common risks of IVF include:

  • Complications retrieving eggs. An aspirating needle is used to collect eggs, and this can cause bleeding or infection.
  • Ovarian hyperstimulation syndrome. This condition is caused by fertility drugs used to induce ovulation. If the ovaries are overstimulated, they may become swollen and painful.
  • Ectopic pregnancy. Up to five percent of women who undergo IVF will experience an ectopic pregnancy, which occurs when the fertilized egg implants outside of the uterus—generally in a fallopian tube—where it can’t survive.
  • The rate of IVF miscarriage is similar to that of natural pregnancies—up to 25 percent—but the older you are, the greater the chance of miscarriage.
  • Premature birth or low birth weight. IVF may slightly increase the risk of pre-term birth and low birth weight.
  • Birth defects. Many experts believe that IVF doesn’t increase the risk of birth defects, although more research is needed. The primary risk factor for birth defects is the age of the mother.
  • Multiple births. If more than one embryo is implanted into your uterus, your risk of multiple births is increased. Multiple pregnancies pose a number of risks, including premature birth and low birth weight.
  • IVF is intense, expensive, and emotionally taxing, and taking good care of yourself while undergoing these procedures is essential for your physical and mental health. Stress can have an important effect on your pregnancy. A solid support system of friends, family members, and even a counselor is important during IVF.

Important Considerations for In Vitro Fertilization 

Learning everything you can about the in vitro fertilization definition and procedure before undergoing IVF will help you make the best choices for you. There’s a whole lot to think about when you’re considering IVF, and much of it has nothing to do with the procedure itself. These are some important questions you should have answers to before you undergo IVF.

How many embryos will be transferred? It’s important to decide ahead of time how many embryos will be transferred. How many usually depends on your age and the number of eggs collected. Older women generally have more embryos transferred, since their rate of implantation is lower. Your doctor will probably follow certain guidelines when determining how many embryos to transfer, keeping in mind the prevention of a multiple pregnancy and any legislation limiting how many can be transferred at one time.

What will I do with extra embryos? You have a number of options concerning extra, unused embryos. You can have them frozen for future use, although not all of them will survive the freeze-thaw cycle. You can donate unused embryos to a research facility or to another couple. You can also choose to have the unused embryos discarded.

What will I do in the event of a multiple pregnancy? The chances of becoming pregnant with multiples is higher with IVF. Multiple pregnancies are riskier than single pregnancies and can affect your and your babies’ health. Understand ahead of time the risks associated with multiples, and consider how you may need to change your lifestyle in order to improve your chances of a healthy pregnancy and birth.

In the case of a large number of multiples, fetal reduction can eliminate some of the fetuses to improve the chances of good health for the remaining babies. This can be a difficult decision to make, since it can have emotional and psychological consequences.

Should I get a lawyer? In some cases, such as when using a gestational carrier or donor sperm or eggs, you may need to file papers in order to become the legal parents of the implanted embryo. If you’re planning on using a donor or gestational carrier, consult with a trained infertility counselor to learn about your rights and the rights of the donor or carrier.

What to Expect When Undergoing In Vitro Fertilization 

In vitro fertilization is a complex procedure, and how exactly it will work for you depends on a number of variables. In general, though, IVF involves five main steps: inducing ovulation, extracting the eggs, retrieving the sperm, fertilization, and embryo transfer.

Step One: Inducing Ovulation 

If you’re using your own eggs, you’ll begin IVF by taking fertility medication to stimulate your ovaries into producing multiple eggs rather than the single one that’s normally produced. Having several eggs to work with improves the chances of successful fertilization.

Different medications may be used during IVF. These include:

Ovary stimulation medications. An injectible medication with follicle-stimulating hormone or a luteinizing hormone—or a combination of the two—may be used to stimulate the development of more than one egg.

Oocyte maturation medications. After eight to 14 days, the follicles are ready for egg retrieval, and you may take a medication like human chorionic gonadotropin (HCG) to promote maturation of the eggs.

Medications to prevent premature ovulation. You may take medications to prevent your body from releasing the developing eggs too early.

Medications to prepare the lining of the uterus. Before the eggs are retrieved or the embryo is transferred, you may take progesterone supplements to make your uterus lining more conducive to implantation.

After one to two weeks of ovarian stimulation, your eggs will be ready for retrieval. To determine the right time to extract the eggs, your doctor may use a vaginal ultrasound to monitor the follicles or a blood test to check your estrogen and progesterone levels.

In some cases, the IVF cycle will be cancelled during this phase of the procedure. This may occur due to too many or too few follicles developing, premature ovulation, or other medical problems. In this case, your doctor will re-evaluate the medications being used and develop a new strategy for the next cycle. Alternatively, you may learn that you’ll need to use donor eggs.

Step Two: Retrieving the Eggs 

Between 34 and 36 hours after your final dose of medication and before you ovulate, you’ll visit your doctor’s office or fertility clinic for egg retrieval. You’ll be given a sedative and some medication for pain.

The usual method of retrieval is transvaginal ultrasound aspiration, which involves inserting an ultrasound probe into your vagina to locate the follicles. A thin needle is then inserted through the vagina and into the follicles to collect the eggs.

If the follicles can’t be located using ultrasound, laparoscopy may be used. During this procedure, a laparoscope, a thin viewing instrument, is inserted into a tiny incision near your navel to guide the needle to the follicles.

It takes about 20 minutes to collect the eggs needed for IVF. The mature eggs are stored in a culture medium and incubated.

Step Three: Collecting the Sperm

 If your partner’s sperm will be used to fertilize the eggs, your partner will provide a semen sample at the doctor’s office or clinic at the time of egg retrieval. In some cases, a needle will be used to extract the sperm from the testicle. The semen is taken to the lab, where the healthy sperm are separated from the seminal fluid.

Step Four: Fertilizing the Egg

 Exactly according to the in vitro fertilization definition, the eggs are fertilized in a glass dish or test tube in the lab. Fertilization occurs in one of two ways:

  • During insemination, mature eggs and healthy sperm are combined and left to incubate overnight.
  • Intracytoplasmic sperm injection (ICSI). During ICSI, a single sperm is directly injected into each single mature egg. This procedure is used when the quality or quantity of semen is low or if previous attempts at fertilization failed.

 If your embryos are undergoing genetic testing, they’ll be allowed to develop in the incubator for five or six days, until they’re large enough for a small sample to be extracted for tests.

Step Five: Transferring the Embryo

 Somewhere between two and six days after retrieval, you’ll head back to the clinic or doctor’s office for the embryo transfer. Although this procedure is generally painless, you may be given a mild sedative to prevent cramping. A long, thin catheter will be inserted into your uterus through your vagina and cervix. A syringe containing the embryo or embryos in a small amount of fluid is inserted into the catheter, and the embryos are placed in the uterus.

After the transfer, you may experience some discomfort, but you can resume your normal daily activities. You may have a little clear or bloody discharge after the procedure, and you may experience mild bloating, cramping, constipation, or breast tenderness.

Six to 10 days after the eggs were retrieved, if the IVF cycle is successful, an embryo will implant into the lining of your uterus.

The Waiting Game

 It will be hard to keep your mind off your uterus for the next 12 days to two weeks, when you’ll head back to the clinic for a blood pregnancy test. If you’re pregnant, you’ll be referred to an obstetrician or other specialist, who will take over prenatal care.

If the procedure was unsuccessful, you can choose to try another cycle. Your doctor will work with you to take steps to improve your success with IVF.

Is In Vitro Fertilization Right for You? 

In vitro fertilization isn’t right for everyone. If you’re having trouble conceiving, your doctor will help you and your partner decide on your next move. If IVF is identified as a viable option, learning everything you can about the procedure will help you make choices that will improve your chances of successful implantation.

References: 

Mayo Clinic: In Vitro Fertilization (IVF)

U.S. National Library of Medicine: In Vitro Fertilization (IVF)

Dartmouth Undergraduate Journal of Science: In Vitro Fertilization