In Vitro Meaning

Each year, thousands of couples across the country choose in vitro fertilization as a means of getting pregnant, most commonly when traditional methods have failed. In vitro fertilization is an assisted reproductive technology (ART). The term “in vitro” is Latin for “in glass.” This term is used across several scientific and medical specialties for research that is conducted in a test tube or other laboratory glass. This term is different from “in vivo,” which means “in life” when studies are conducted inside an organism.

There are other ART techniques that involve an in vivo fertilization. This includes the use of artificial insemination. This process involves delivering a man’s sperm into the uterus to increase the likelihood that a woman will conceive. Artificial insemination is an option for women whose partners may have sperm that may not have effectively traveled through the cervix to the uterus. However, in vitro techniques will result in fertilization outside the body, with subsequent implantation into a woman’s uterus.

The term “in vitro” is appropriate for describing in vitro fertilization because an egg and sperm are collected from donor parents and combined in a laboratory for fertilization (a more detailed description of this process is included below). Because fertilization happens outside the womb, doctors use the term “in vitro.” Other names for the process may include IVF or in vitro. This ART method is rarely the first option utilized, but instead is one of the last because of its cost, time-consuming nature, and invasiveness in retrieving eggs.

in vitro meaning

What Are Some of the Major Milestones in In Vitro Fertilization?

While the greatest strides in in vitro fertilization have been in the past few decades, the concept behind the treatment has been around for more than one hundred years. According to the journal “Reproduction,” experiments that would serve as the foundation for IVF began in 1878. Some of the major milestones in in vitro’s history include:

  • In 1884, the first reported artificial insemination took place, injecting donated sperm into a woman’s uterus.
  • In the 1940s, researchers learned how to freeze donated sperm. These techniques would form the basis for sperm banks, which started opening in greater numbers in the 1970s.
  • In 1959, a research study concerning rabbit eggs that were fertilized in vitro that later developed into normal offspring served as the basis for two other important research studies in 1963 and 1964 regarding hamster gene studies.
  • In 1967, the U.S. Food and Drug Administration (FDA) approved the medication clomifene (Clomid) to treat infertility in women who do not ovulate. The medication acted as the gateway for assisted reproductive technology, including in vitro.
  • In 1978, researchers reported the first successful human birth from an IVF embryo. This was research conducted at Oldam General Hospital in Great Britain with the couple John and Lesley Brown. On July 25, 1978, Mrs. Brown gave birth to their daughter Louise, who is known as the first “test tube baby.” However, in vitro fertilization does not happen in test tubes, but instead in petri dishes. These are small, plastic or glass circles that have a medium that supports the growth of fertilized embryos.
  • In the early 1980s, couples began freezing their embryos for use in subsequent IVF cycles. According to the “Santa Barbara Independent,” there are an estimated 500,000 frozen embryos in the United States.
  • In 1992, researchers first reported the first successful intra-cytoplasmic sperm injection (ICSI). This involves a laboratory professional injecting a single sperm into an egg instead of simply exposing the egg to collected sperm. Before the invention of ICSI, thousands of sperm had to be collected. However, if a man had low sperm counts, the couple could not conceive using in vitro. This expanded the availability of options for treatment of couples who could not get pregnant.
  • As of 2010, more than 3 million babies have been born as a result of in vitro. On a yearly basis, an estimated 300,000 couples utilize IVF in an attempt to get pregnant, according to the “Santa Barbara Independent.”

In vitro fertilization has been the product of more than a hundred years of research and milestones that have helped couples conceive when it would not have otherwise possible. As researchers continue to develop new medications and methods, the success rates of in vitro has continued to increase. Doctors are also gaining a greater understanding regarding fertility and genes that may affect a couple’s likelihood for conceiving as well as passing on traits that can result in miscarriage for women.

Why Might a Couple Choose In Vitro?

In vitro is chiefly used as a treatment for infertility. If a couple has unprotected sex for a year without conceiving, this can be a sign of an underlying medical condition and fertility concerns that can warrant further interventions. While in vitro is not the only option in terms of fertility treatments, it is one that can be beneficial for infertility related to a medical condition, such as endometriosis or polycystic ovary syndrome. Women with premature ovarian failure, uterine fibroids, or other ovulation disorders can also benefit. Often, women attempting to conceive at an age older than 35 may find greater success through in vitro. However, fertility naturally declines with age.

Some people use in vitro as a method of fertility preservation. For example, if one part of a couple is going to undergo cancer treatments that can affect fertility, they may choose to go through an IVF cycle to create embryos that could be used to have a baby at a later time. The embryos are then frozen until the couple is ready to try to conceive or use a surrogate to carry their baby.

Another reason why a couple may turn to in vitro is if one or both of the couple has a history of a genetic disorder. An example could include cystic fibrosis. While a laboratory cannot screen for all types of genetic disorders, they can screen an embryo for some disorders. Testing is known as preimplantation genetic screening (PGS). Because a woman is also at greater risk for having a child with birth defects as she ages, women may wish to have their embryos screened for the incidences of genetic abnormalities, such as Down’s syndrome, which results from three copies of chromosome 21. PGS could reduce the couple’s likelihood of having a child they passed their genetic disorder on to.

How the In Vitro Process Works

Most couples will seek in vitro treatments at a fertility clinic, where a doctor specializes in treating a couple’s problems related to fertility. The doctor will conduct a thorough interview with the couple regarding their health histories, how long they have been trying to conceive, and their desire to pursue various fertility treatments. Depending upon the couple’s health history, a doctor may also recommend testing to determine potential underlying infertility causes as well as to test how many eggs a woman may still have. This is detected using blood tests known as ovarian reserve tests. Additionally, a doctor may also recommend conducting testing for the male, to determine the number and quality of his sperm. At this time, a doctor may recommend either proceeding with in vitro fertilization treatments or considering pursuing either donor egg or sperm as a means to conceive. Sometimes a woman may not have enough eggs remaining to successfully harvest the eggs for in vitro. This is why it is important that a doctor conduct testing before beginning the treatments.

If a doctor recommends moving forward with in vitro, the process will begin by testing to determine when a woman is ovulating. This is important because a doctor will administer medications that will promote the release of more than one egg so multiple eggs can be harvested for possible embryo fertilization. Right before the eggs are scheduled to be retrieved, a woman will receive a shot that will ideally cause her to release the eggs in a timely fashion.

On the day of egg retrieval, a doctor will perform a procedure known as follicular aspiration to remove the eggs. This procedure involves inserting a small needle using ultrasound imaging to remove the very small eggs. Ideally, the procedure should not cause a woman any pain or discomfort. However, some mild bleeding and cramping may occur.

The clinic will collect the man’s sperm, usually produced through masturbation. However, if a man cannot donate the sperm in this manner, a doctor may have to use retrieval via invasive methods.

A fertility doctor may discuss the treatment options with a couple for fertilization. Sometimes, a laboratory will simply expose the eggs to the sperm for fertilization. Other times, if there are concerns over sperm quality or fertilization, a couple will choose intracytoplasmic sperm injection or ICSI. This technique involves injecting a single sperm into the egg. Although this is associated with greater chances for conception, it also is more costly and time-consuming. However, some fertility programs recommend only using ICSI for fertilization as it is associated with greater success rates.

Once the fertilized egg begins to divide, doctors consider it an embryo. The process from fertilization to embryo creation takes about five days. If a couple desires PGD, this testing process is performed about three to four days after fertilization occurs. However, not all centers provide PGD due to its sometimes-controversial nature where some experts contend this is the equivalent to parents manipulating the process of natural selection.

Once the embryos as ready, a woman will return to the fertility clinical for artificial insemination. This is the process where a doctor will insert a special catheter through her vagina and into her uterus. Prior to insemination, a doctor will discuss how many embryos should be transplanted. The more embryos that are transplanted, the greater likelihood for success. However, more embryos also increases a woman’s chances of a multiples pregnancy. Being pregnant with more than one child can result in increased miscarriage risks. As a general rule, the older a woman is, the more embryos that may be transplanted due to the lower conception rates associated with aging.

Ideally, the artificial insemination process will result in a successful pregnancy. However, if a woman does not become pregnant with the first IVF cycle, she may choose to conduct future cycles. Some women will freeze additional embryos in case they are required for additional IVF attempts.

Conclusions on In Vitro Meaning

Infertility and the desire to have a baby has been a challenge for thousands of years. In the past 100 years, researchers have made great strides in helping women conceive when they may not have been otherwise able. While in vitro does not have a guarantee of success, an estimated 1 percent of all babies born in the United States are born to parents who sought in vitro treatments, according to the “Santa Barbara Independent.”

In vitro can be associated with being a very stressful process. As a couple has likely tried to conceive for a year or years, they often view in vitro as their last effort toward conceiving. As a result, tensions, stress, and depression can all be emotions that accompany an in vitro cycle. In addition to the mental health side effects, taking fertility medications, retrieving eggs, and conducting artificial insemination can have physical effects. Examples of these include:

  • Bloating
  • Headaches
  • Mood swings
  • Stomach pain

In addition, the medications can cause a syndrome known as ovarian hyperstimulation syndrome (OHSS). This syndrome causes a person to experience swelling in the ovaries that causes significant pain, swelling, nausea, and shortness of breath. Sometimes, severe cases may require treatment that involves draining fluid buildup on the ovaries to reduce symptoms.

References:

American Pregnancy Association: In Vitro Fertilization (IVF)

The Embryo Project Encyclopedia: In Vitro Fertilization

MedlinePlus: In Vitro Fertilization

Reproduction: Early History of In Vitro Fertilization

Santa Barbara Independent: In Vitro Fertilization, Part I: A Brief History

VeryWell: In Vitro Definition