Overview of Assisted Reproductive Technology (ART) Techniques
Assisted reproductive technologies, or ART for short, refers to procedures that assist with fertility by handling eggs or embryos. This definition, provided by the American Center for Disease Control, or CDC, doesn’t include treatments where only sperm is managed, like intrauterine inseminations. It also doesn’t include procedures that stimulate the ovaries without intending to retrieve eggs.
The first successful instance of a particular kind of ART, called in vitro fertilization (IVF), happened in 1978 in England. In IVF, a woman’s egg is removed, fertilised outside the body, and then placed back into the woman’s womb. In this historic case, the egg was taken from the woman during her normal monthly cycle, fertilised in a laboratory and then placed back into her womb.
In recent years, IVF and other ART techniques have continued to improve and become more widely available worldwide. This overview will talk about current ART techniques, why they’re used and the risks associated with them.
Of all the ART procedures, IVF is the most commonly performed. Along with IVF, we’ll also discuss related techniques like cryopreservation, which is the freezing and storing of eggs or embryos, and intracytoplasmic sperm injection (ICSI), a method where a single sperm is injected directly into an egg.
Anatomy and Physiology of Assisted Reproductive Technology (ART) Techniques
The key parts of a woman’s reproductive system that are crucial to understand Assisted Reproductive Technology (ART) are the ovaries, fallopian tubes, and uterus. The ovaries are part of a feedback loop along with the hypothalamus and pituitary gland in the brain, which regulates a woman’s monthly menstrual cycle. These oval-shaped components are the female sex organs where eggs mature and grow for potential fertilization.
The ovaries also produce two important hormones: estradiol and progesterone. These ovaries connect to the uterus and to the wall of the pelvis via the ovarian ligament and the suspensory ligament of the ovary, respectively. The latter contains the blood vessels and nerves that supply the ovary. As such, understanding this anatomy is crucial to safely and effectively retrieving eggs for in-vitro procedures.
The uterus or womb is reactive to the various hormone levels from the ovaries. It is located in the lower abdomen, between the bladder and rectum. It is made up of a body and the cervix, which acts as a gateway to the vagina. The body of the uterus has three layers: inner layer (endometrium), middle layer (myometrium), and outer layer (perimetrium). The endometrium or inner layer is further divided into two layers: the functionalis and the basalis. The functionalis layer goes through various changes in preparation for potential pregnancy during each menstrual cycle. If a fertilized egg is not implanted during the cycle, this layer sheds off.
The fallopian tubes are muscular tubes that extend from the uterus to the ovaries. Their primary function is to transport eggs to the uterus, with fertilization usually occurring within the tubes themselves. The tubes enable this process by catching the egg with their fringed ends, using muscle contractions and hair-like structures to move the egg or fertilized embryo into the uterus for implantation.
Why do People Need Assisted Reproductive Technology (ART) Techniques
Assisted reproductive technologies, like IVF (in vitro fertilization), are often used to help people who are having trouble getting pregnant. In some cases, a woman may have blocked or damaged fallopian tubes that prevent the sperm from reaching the eggs. In such cases, IVF can bypass the tubes and help with pregnancy.
There are other reasons why couples might turn to IVF. These include male infertility, a decrease in ovarian reserves (the number of eggs a woman has left), failure of the ovaries, issues with ovulation, or unexplained reasons for not being able to get pregnant. If the woman has a medical condition that makes pregnancy risky, or a problem with her uterus, a gestational carrier (another woman who carries and gives birth to the baby) could be used with IVF.
IVF is not just for infertility. Some people use it when they want to test an embryo for certain genetic disorders before it’s implanted in the womb. Some people also use IVF to preserve their fertility, like before treatments that can harm the reproductive system, or if they want to delay having children. In these cases, women can choose to freeze their eggs or, if they are in a stable relationship, they can freeze embryos for future use.
When a Person Should Avoid Assisted Reproductive Technology (ART) Techniques
Before starting Assisted Reproductive Technology (ART), a method to help with fertility issues, potential risks to the mother from both the ART techniques and the pregnancy itself are talked about with the patient. Certain health conditions that a woman may have, especially heart and lung conditions like high blood pressure in the lungs (pulmonary hypertension) and heart failure, can make a pregnancy quite risky. This is why a thorough health check-up is done before conception to look for these conditions. But even if these conditions are present, there are still options for having a child. One such option is using a gestational carrier, which is another woman who carries the baby.
Equipment used for Assisted Reproductive Technology (ART) Techniques
According to the guidance provided by the American Society of Reproductive Medicine, which offers recommendations for labs specializing in fertility and male reproductive health, there are several essential pieces of equipment needed for the care and treatment of eggs and embryos:
* An incubator: This is like a special “oven” used to encourage the growth and development of eggs and embryos. It controls temperature and other conditions to mimic those in the female body.
* A special microscope: This enables accurate handling and the extremely tiny adjustments needed for eggs and embryos.
* Devices to monitor and control pH and temperature: These ensure the optimal conditions for the embryos are maintained.
* Warming blocks: A device used to keep eggs, embryos, and other tools at a suitable temperature.
* A Laser: This is specifically used for performing a biopsy, or a sample collection, on the embryos.
* Cryopreservation equipment: This is essentially a very cold storage unit, like a freezer, that uses liquid nitrogen to preserve eggs and embryos.
* A laboratory centrifuge: This spins samples at high speed for separation or concentration of certain components.
* A laminar flow hood: This device protects the work environment from dust and other airborne particles that could contaminate the eggs and embryos.
* Culture media: This provides the necessary nutrients required for embryos to grow and develop.
* A refrigerator: For storing certain samples and substances.
* Air filtration system: To help ensure a clean, dust-free environment for the delicate work with eggs and embryos.
Who is needed to perform Assisted Reproductive Technology (ART) Techniques?
According to the American Society for Reproductive Medicine (ASRM), there’s a team of experts needed in order to offer treatments like IVF (In Vitro Fertilization), which is known as assisted reproductive technologies. This team is made up of:
A medical director: This person oversees the whole process to ensure everything runs smoothly. They coordinate between different specialists involved in your care.
A physician who specializes in reproductive endocrinology and infertility: These are doctors who understand the hormones that control our bodies and can treat issues that make it hard for women to get pregnant.
A physician who specializes in male fertility: This doctor helps with issues that may make it difficult for men to contribute to pregnancy.
Nurses who have specialised training in reproductive medicine and assisted reproductive technologies: They take care of you during the process and provide you with the necessary instructions, medications, and support throughout your journey.
An embryology laboratory director: This person manages the lab where your eggs and sperm meet to become embryos, ensuring everything is going as planned.
An andrologist: This is a scientist who specifically studies male health, particularly relating to the problems of the male reproductive system and sperm health. They bring this expertise to the lab process.
Laboratory personnel to perform hormone tests: These are the people who check the hormone levels in your blood. Hormones play a big role in getting pregnant, which is why it’s so important to keep track of your levels during the process.
An individual with experience in gynecologic ultrasound: Doctors, technicians, or nurses with this experience will take clear pictures of your reproductive organs to ensure everything is developing as expected.
A mental health professional with fertility counseling experience: Fertility treatments can be emotionally challenging. This person helps you deal with these emotions and provide strategies for managing stress and anxiety.
Lastly, a genetic counselor: This professional helps you understand the risk of genetic disorders and can guide decisions about pursuing certain fertility treatments.
Preparing for Assisted Reproductive Technology (ART) Techniques
Before starting treatments using Assisted Reproductive Technologies (ART), doctors perform thorough exams to understand the causes of infertility. Infertility means not being able to get pregnant despite having regular unprotected sex for a year. This examination can also start after six months without getting pregnant for women over 35, or in situations where known problems exist such as issues with the uterus, fallopian tubes or male infertility.
For the evaluation, doctors will take a detailed medical history. This includes questions about a woman’s menstrual cycle, past pregnancies, how long they’ve been trying to get pregnant, previous infertility treatments, general health, any surgical procedures they’ve had, as well as family history, and lifestyle habits. Doctors will also perform a physical examination where they’ll check vital signs, body mass index, thyroid function, signs of excessive male hormones, and a pelvic examination.
Females will have to undergo several tests to help doctors understand their fertility health better. These include measuring the levels of certain hormones in their blood and performing ultrasound checks of their reproductive organs on specific days of their menstrual cycle. These tests help to understand the woman’s fertility potential, the performance of their ovaries, and if there are hormonal concerns affecting the chance of becoming pregnant.
Another aspect of the evaluation includes checking the internal health of the uterus and surrounding area with a detailed transvaginal ultrasound scan. This scan can help identify if there are any issues affecting fertility such as growths like polyps or fibroids within the uterus, or any irregularities with the shape of the uterus.
The ultrasound can also help identify other conditions that might be making it harder to get pregnant, such as hydrosalpinx (a condition where the fallopian tube is blocked with fluid) or endometriosis (a condition where tissues that should line the uterus grow outside it).
For males, their evaluation involves analyzing a semen sample to check sperm health. Both men and women usually also undergo checks for infectious diseases like syphilis, hepatitis, and the human immunodeficiency virus (HIV).
How is Assisted Reproductive Technology (ART) Techniques performed
In vitro fertilization (IVF) is the most used method among assisted reproductive technologies. It involves taking eggs from the ovaries and fertilizing them outside of the body. The fertilized egg is then returned into the womb. The IVF process may also include genetic testing and injecting the sperm directly into the egg. If there are extra embryos, they can be frozen for future use, or for preserving fertility.
The first step in IVF is called controlled ovarian stimulation, which lets doctors collect multiple eggs in a cycle, raising the chances of pregnancy. Although it’s still possible to retrieve a single egg during a woman’s natural menstrual cycle, controlled stimulation is more common these days. There are various drugs used for this purpose, each with their advantages and disadvantages. A common technique for controlled stimulation uses hormone injections to encourage the growth of multiple eggs. The growth of these eggs is then tracked using ultrasound imaging. Once the eggs are mature, the final maturation is triggered using another hormone injection.
After this, the eggs are retrieved from the ovaries. This used to be done via a surgical procedure, but nowadays, doctors usually retrieve eggs through a small needle inserted into the vagina, with the help of ultrasound imaging. The more eggs that are collected, the better the chances of a successful birth.
Next, the eggs are fertilized outside the body by mixing them with sperm in a special liquid. The sperm can be obtained in different ways, depending on the situation. For example, if the man has fertility issues, a single sperm can be injected directly into each egg. The fertilized eggs develop into embryos in a controlled environment, and doctors typically wait until they’re either three or five days old before transferring them into the woman’s uterus. Embryos that are five days old have a better chance of leading to pregnancy.
Doctors can also do genetic testing on the embryos before putting them back into the womb. This can screen for potential chromosome abnormalities or certain genetic disorders. However, such testing isn’t perfect, and can sometimes provide false-positive results.
Possible Complications of Assisted Reproductive Technology (ART) Techniques
Ovarian Hyperstimulation Syndrome (OHSS) is a potentially dangerous side effect of medical procedures that stimulate the ovaries, like in vitro fertilization (IVF). It happens when the ovaries overreact to medicines that stimulate egg production. The chance of getting OHSS varies but moderate to severe cases occur in about 1 to 5% of women.
The syndrome happens when big doses of hormones cause too many eggs to mature, leading to an overproduction of other hormones and growth factors such as the Vascular Endothelial Growth Factor (VEGF). This results in fluid moving from the blood vessels into the belly and chest areas causing water retention and other symptoms like kidney injury and blood clots. Women who are more likely to develop OHSS include those with Polycystic Ovary Syndrome (PCOS), larger numbers of eggs retrieved (over 24), and high estrogen levels (over 3500 pg/mL).
For those with moderate to severe OHSS, the treatment usually involves replenishing bodily fluids, removing excess fluid from the belly, and getting medicine to prevent blood clots. Women at risk for OHSS are advised not to go through with a fresh transfer and freeze all embryos until their stimulation has gone down. They should replace the HCG hormone used for final maturation with a different hormone if possible. Additionally, daily use of the drug cabergoline for eight days may help prevent OHSS. These women can then safely have a frozen embryo transfer one to two months later, when the stimulation of the ovaries has gone down.
Antenatal and Neonatal Complications
Having more than one baby at a time is the most common complication of procedures like IVF. In 2009, 41.1% of babies conceived through IVF were multiple births, compared to 3.5% of babies conceived naturally. Efforts to reduce this by transferring fewer embryos at once has significantly lowered this rate, with 73.6% of babies born via IVF in 2017 being single births.
Having multiple babies at once can create risks for both mum and babies. Mums may be more likely to have extreme morning sickness, gestational diabetes, and high blood pressure during pregnancy. Multiple pregnancies also increase the chance of babies being born premature and can also raise the risk of stillbirth by five times and death shortly after birth by seven times.
Medical providers try to limit the risk of multiple births through lower drug doses, closely tracking hormone and egg development, and implanting fewer embryos at a time. Once a multiple pregnancy is realized, the doctor should discuss the heightened risks and, if suitable, may propose a procedure to reduce the number of fetuses.
Even single baby IVF pregnancies might have higher risks compared to those conceived naturally. These risks include infant death around the time of birth, premature birth, low birth weight, cesarean section, pregnancy complications like placenta previa (where the placenta blocks the cervix), placental abruption (where the placenta separates from the uterus prematurely), and preeclampsia (high blood pressure during pregnancy). These possible risks should ideally be discussed with the patient, bearing in mind that the quality of data is limited.
There is modest evidence supporting a small increase in the risk of birth defects in babies born via IVF, particularly those using Intracytoplasmic Sperm Injection (ICSI), a technique where a single sperm is injected directly into an egg. Regular monitoring during pregnancy, such as ultrasound scans, may be suggested for those who conceived through IVF.
What Else Should I Know About Assisted Reproductive Technology (ART) Techniques?
Assisted reproductive technology, or ART, helps people or couples who might not be able to have children naturally due to issues such as infertility, previous treatments that damaged their reproductive system (gonadotoxic therapies), or certain inheritable genetic conditions.
Interestingly, according to the Center for Disease Control, nearly 2% of babies born in the US in 2017 were conceived using ART. In that same year, there were around 200,000 ART procedures that resulted in the transfer of an embryo into a woman’s uterus, leading to over 78,000 live births.
The numbers of people using ART to have children is predicted to increase as more people have access to the treatment, more people delay having children until later in life, and as insurance companies increase their coverage of ART procedures.
Given this trend, it’s crucial that healthcare professionals who focus on women’s health and reproductive health understand when it’s appropriate to refer a patient to a reproductive endocrinologist and infertility specialist – these are doctors who specialize in helping people have children through treatments like ART.
