What is IVF? In vitro fertilization explained

What is IVF?

IVF, or in vitro fertilization, is the most common type of assisted reproductive technology (ART) that can be used to help individuals and couples start a family. During ‘in vitro’ (Latin for ‘within the glass’) fertilization, conception between the egg cell and sperm cell happens in a laboratory instead of in the woman's reproductive tract [1]. This can be done using a heterosexual couple’s own egg and sperm or using a donated egg and/or sperm. Unlike intrauterine insemination (IUI), when sperm is medically inserted into a woman to help increase the likelihood of conception [2], IVF involves medical intervention of both the egg and sperm.

IVF can be used to help couples who are having trouble conceiving on their own, as well as those individuals or couples who need or choose to use egg or sperm cells from a donor [3,4]. IVF is also used by those who are trying to become pregnant using embryos or eggs that have been frozen. Those who know themselves to be carriers of certain genetic disorders can also use IVF with preimplantation genetic testing to ensure serious conditions are not passed on [5].

Why do people choose IVF?

While IVF has been extensively studied and doctors and scientists confirm it to be a safe medical procedure, the physical, mental, and emotional toll of the procedure, as well as the cost, mean that it’s most often used by those who are struggling with infertility issues, those who are trying to conceive without a partner, same-sex couples, and those using frozen egg cells or embryos. The decision of when to start IVF is individual and depends on your and/or your partner’s age, medical history, and personal circumstances.

How does IVF work?

Each decision to undergo IVF and journey through the procedure is unique, but let’s go through the most basic steps that are common for most people. 

Preparation

Depending on where you live, IVF can be part of a public health program, or it might involve private clinics and private insurance. Regardless, there is usually a referral process and medical check-up(s) for both you and your partner. Doctors might advise a length of time spent trying to conceive on your own prior to starting IVF, which can depend on your individual age and medical history, before referring to a fertility clinic. In addition to a physical examination, doctors compile a comprehensive medical profile that includes information about menstruation, past pregnancy, experiences of infertility, prior fertility treatments, previous surgeries, medical conditions amongst family members, and social and environmental habits. [1,6] 

If you and your partner are using your own sperm and eggs for IVF, a doctor’s office or fertility clinic will have you both undergo a series of tests to check the quantity of eggs and the health of sperm. Whether you are using your own eggs or donor eggs, women will also have blood drawn to check for different hormone levels like follicle stimulating hormone and estradiol (a form of estrogen) to help doctors understand ovulation in your body. Ultrasounds of your uterus and ovaries will also help doctors determine if there are any anatomical factors, like polyps or fibroids, that could impact your ability to become pregnant. [1,6]

Ovarian Stimulation

The IVF process sometimes starts with a daily hormone medication that suppresses the body’s natural ovulation process. This is taken for between two and three weeks [6]. After a medical care team confirms that the medicine worked, a different hormonal medication is used daily for around two weeks to encourage the body to increase the development of multiple follicles (the small sacs in the ovaries that each contain an immature egg cell). This is known as ovarian stimulation [7]. In a natural, healthy menstrual cycle, usually one egg cell, or oocyte, is matured and released. Older forms of IVF, referred to as natural cycle IVF, utilize the single oocyte released during the natural menstrual cycle. However, hormonal intervention has enabled doctors to control the maturation of the eggs more precisely and potentially increase the number of eggs that can be used for IVF. For this reason, ovarian stimulation is more commonly practiced because it increases the chances of a successful pregnancy.

Egg retrieval

Doctors use vaginal ultrasounds to monitor the development of eggs inside your ovaries and adjust your hormonal medications to help them mature. When the egg cells are ready, doctors will retrieve them from the ovaries using a vaginal ultrasound and a small, thin needle [6]. This is usually done under general anesthesia or conscious sedation [1].

If you are using sperm from a partner or someone you know, it is usually collected via an ejaculation sample around the same time as the egg retrieval. Sperm used for IVF can also be collected surgically in the case of male factor infertility, or be provided by a sperm donor. [1]

Fertilization

Once the mature eggs have been retrieved, fertilization between sperm and egg cells takes place in vitro (in a laboratory). In most cases, someone from your care team will contact you and let you know how many embryos have been made and how many they might be able to use. The embryos develop for transfer on around day three (known as the cleavage stage) or around day five (blastocyst stage). Blastocyst stage transfers are more common and associated with higher success rates. [1] 

Preimplantation genetic testing (PGT) is typically done after fertilization to identify possible genetic disorders before embryo transfer. PGT can be done by testing the outermost layer of cells of early-stage embryos, the cell layer that protects the inner cells that will eventually develop into the fetus. While PGT can test for many chromosomal abnormalities, antenatal screening tests during pregnancy are still recommended [8]. PGT was initially used to allow doctors to select the healthiest embryos for transfer, but it can also be used to screen embryos for sex (in some countries where this is legal) and other medical conditions.

Embryo transfer

Doctors transfer embryos using a thin tube inserted into the vagina, through the cervix, and directly into the uterus. An ultrasound is also used to help doctors guide the transfer [6]. In most cases, a single embryo is transferred at a time, and the remaining embryos are cryopreserved in the laboratory. In some cases, multiple embryos can be transferred at the same time. This will depend on where you live and your personal medical situation.

The embryo transfer can take place during the days after an egg retrieval, but it can also take place weeks or months later using previously frozen embryos. Transfer using frozen embryos has become more common because it has been associated with higher implantation and pregnancy rates [1]. Ovarian simulation can be stressful for the body, and sometimes embryo transfer can be more successful after the body has had time to recover. It can take multiple embryo transfers, or rounds of IVF, before implantation occurs and a pregnancy can start to develop.

How long does IVF take?

A single round, or cycle, of IVF takes between four to six weeks from the start of ovarian stimulation to a pregnancy test. Before starting IVF preparation can take up to a month or more, depending on your personal situation, medical history, and the referral process where you live. Unfortunately, all the steps of IVF can be followed, but there might not be any healthy eggs retrieved, or an embryo may not implant or develop properly after a transfer. In such cases, multiple cycles or individual steps of IVF are repeated, which can make the entire IVF process last longer. 

How to prepare for IVF

You can prepare for IVF by prioritizing your own mental and physical health, just as you would when preparing for pregnancy. Learning as much as you can about the IVF process and the treatment, particularly getting to know the clinics where you live and where you might seek treatment, can also help you feel more comfortable at the first appointments. It’s completely normal to have questions or be nervous, so be sure to ask any and all questions of your care team. While starting IVF can feel scary and unfamiliar, try to remember there are no dumb questions and IVF clinics are staffed with caring, experienced professionals who are there to support you through this process. [9]

How effective is IVF?

IVF success rates vary greatly based on a number of factors, such as the age of the woman undergoing treatment and the underlying reason for undergoing IVF. Statistics can vary widely, and IVF is highly individual, so it’s important to discuss potential outcomes with your doctor before starting treatment.

Success rate by age 

Fertility is impacted by a number of different factors, including age. Unfortunately, advanced maternal age has an impact on one’s ability to conceive and carry a healthy pregnancy, whether the baby is conceived naturally or through ART, like IVF. There are countless personal, professional, social, and financial considerations that influence when we may decide to start a family. [10]

Various medical authorities offer IVF success estimators, or success rates. Some, like the calculator from the American Center for Disease Control, estimates rates of success based on information from your background and medical history, as well as the reason you are pursuing IVF [11]. 

The UK Human Fertilization and Embryology Authority statistics from 2022 [12] stated that birth rates using fresh embryos were as follows: 

• 35% for women 18-34
• 26% for women aged 35-37
• 18% for women aged 38-39
• 10% for women aged 40-42
• 5% for women aged 43-44

If you are concerned about how your age might impact your ability to conceive using IVF, it’s important to speak with your medical team. While statistics like these can be helpful, IVF prognoses should be made by a medical professional on a case-by-case basis.

Side effects of IVF

IVF is a physically and emotionally demanding treatment. Some side effects are related to the hormonal medications involved in ovarian stimulation, while others are linked to the stress and anxiety involved in what can be a very intense and emotional experience. IVF side effects can be very different depending on your personal situation, as well as the specific combination and dosages of the hormonal therapies your doctors are using. [13]

It can be helpful to familiarize yourself with the potential range of side effects so that you can communicate any concerns or troubling symptoms to your doctor for guidance and adjustments before and during treatment. Physical side effects can include general discomfort, pelvic pain, weight gain, and bruising or pain at the site of injection. Emotional side effects can include mood swings, depression, feelings of sadness, and anger. Stress and anxiety can also affect the relationship and intimacy you might experience with your partner, which in turn can worsen or intensify other physical or emotional side effects. [13]

Both physical and emotional side effects can be linked to hormonal medications and/or general stress and anxiety, so it’s important to stay aware of how you are feeling and to communicate any concerns you have with your doctor regularly throughout the IVF process. 

IVF benefits 

IVF allows individuals and couples to have a baby in situations where conceiving naturally may be unlikely or impossible. Advances in IVF technology and methods continue to make the process safer and more effective, while improving the experience for women and families undergoing treatment [12]. More widespread use of the procedure is also helping to make it more accessible through both public health systems and insurance systems. At the same time, access to the procedure is nowhere near universal, and experiences can vary depending on where the treatment takes place.

IVF can also provide reproductive freedom and flexibility in family planning. Egg freezing can help those who want to wait to have children feel more free to do so. Additionally, if you undergo IVF and have embryos frozen, it’s also possible to use those embryos later to have more children.

IVF risks/drawbacks 

There are both medical and psychological risks to IVF treatment. Discussing potential risks can help you navigate the process with your partner and/or loved ones, and can help you find support and guidance with your fertility care team. 

Depending on where you live, the high cost of treatment and financial burden can be significant. The procedure itself can be a long process that can be psychologically challenging, can impact your day-to-day life, and can place stress on the relationship you have with your partner and loved ones. 

There are also medical, or physical, risks involved with IVF. In some cases, ovarian stimulation can lead to ovarian hyperstimulation syndrome (OHSS), which is a serious but rare complication that affects an estimated 1-5% of those who undergo IVF. OHSS occurs when too many follicles grow in the ovaries, leading to painful swelling that can cause fluid leakage and further medical complications. The risk of OHSS is linked to some underlying conditions, like polyendocrine metabolic ovarian syndrome (PMOS), which will be screened for during the preparation process before starting IVF treatment. [1,6]

Scientists continue to investigate whether fertility treatment has any long-term effects on health. Some studies have found small associations between assisted reproductive technology and later cardiovascular disease, but it remains unclear whether treatment itself is responsible. Underlying infertility, conditions such as PMOS, and pregnancy complications such as pre-eclampsia or gestational diabetes may also contribute. Long-term monitoring may therefore be recommended based on a person’s individual cardiovascular risk factors and pregnancy history, rather than IVF treatment alone. [14]

Other common risks of IVF include ectopic pregnancies, when the embryo implants in the fallopian tube, and having multiples. The risk of having twins or triplets (or more) is significantly higher when more than one embryo is transferred. Multifetal pregnancies are at a higher risk of complications like hyperemesis gravidarum (extreme nausea during pregnancy), gestational diabetes, and blood pressure-related issues like preeclampsia. [1]

How to increase the chances of pregnancy with IVF

There are some lifestyle factors that can affect your chances of getting pregnant and supporting a healthy pregnancy. You can prepare yourself for pregnancy by trying to eat a healthy and balanced diet, take folic acid, try to maintain a healthy weight, and stay active [15]. Small changes like these can improve both your physical and mental health, and can make a difference when you’re trying to get pregnant.

Coenzyme Q10 has also been studied as a supplement taken during IVF. There is research to suggest it may improve ovarian response, including the number of eggs retrieved, and possibly clinical pregnancy rates — particularly in people with lower ovarian reserve or a previous poor response to ovarian stimulation. However, it has not been shown consistently to increase live birth rates and is not routinely recommended as part of IVF treatment. If you’re considering CoQ10, discuss it with your fertility specialist first. [16]

When to see a doctor

If you think IVF might be right for you, contact your OB-GYN or doctor to start the conversation. Because IVF is invasive and expensive, starting the treatment can be a long process. Whether you and your partner are struggling with fertility issues, you are looking to have a baby on your own, or you are interested in egg or sperm donation, it’s important to talk to your healthcare team for guidance and advice. In general, if you have been trying to get pregnant for a year or more, or more than six months if you’re over the age of 35, it’s advised to consult a doctor [17].

Supporting your individual fertility journey with Natural Cycles

Empowering women with knowledge is core to everything at Natural Cycles. FDA-cleared for planning or preventing pregnancy, the Natural Cycles app uses its first-of-a-kind algorithm to analyze your fertility status daily and provide you with important information about your menstrual cycle, like when you might ovulate and get your period. NCº Plan Pregnancy helps you find the most fertile days in any cycle, and you can make a note of how your IVF journey is going with customized tracking. In addition, you can also download your unique Cycle Report as a handy PDF to share with your doctor. So whether you’re at the start of your fertility journey, embarking on IVF, or are already having fertility treatment, get started today to find out how NC° can support you.