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Embryo freezing, also known as cryopreservation, is an assisted reproductive technology which involves storing preimplantation-stage embryos created through in vitro fertilization (IVF). Cryopreservation is done at extremely low temperatures (-196°C or -321°F) to halt embryo development and preserve their vitality, in a process called vitrification. Following vitrification, these embryos can be safely cryopreserved (frozen) for extended periods until they are thawed for transfer back to the uterus (frozen embryo transfer).  

Cryopreservation is necessary when preimplantation genetic testing (PGT) is chosen. Typically, fresh embryos undergo a biopsy before freezing to allow time for the genetic tests to be conducted. However, there are cases where patients decide that they want to perform genetic testing of previously frozen embryos. In these circumstances, frozen embryos must be thawed for biopsy, then refrozen until further use.  This means that the embryos will undergo an additional freeze-thaw round compared to the typical protocol.

Diminished ovarian reserve is a condition in which the amount (quantity) of oocytes left in a women’s ovaries is low, as determined by ovarian reserve testing. This might result in infertility for some women. In addition, for females going through fertility treatments, DOR may put them at risk of having a poor response to fertility drugs.

Red light therapy is the use of visible light emitted from low-energy lasers with the goal of stimulating cellular processes. Red light is just one type of visible light on the electromagnetic spectrum (Figure 1). In addition to visible light, the electromagnetic spectrum includes radiowaves, microwaves, infrared (IR), ultraviolet (UV), X-ray, and gamma rays. The implementation of light sources as a form of therapy is sometimes called photobiomodulation, and it aims to promote healing, regenerative, and/or restorative function on target cells and tissues.

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Sexually transmitted infections (STIs) can potentially damage the reproductive organs and lead to infertility. It is crucial for sexually active individuals, regardless of age, gender, or sexual orientation to undergo STI testing regularly in order to proactively take responsibility for their sexual health. Early diagnosis and management of STIs are essential for avoiding long-term harm to reproductive organs and for maintaining fertility. This article covers what STIs are, how they may impact fertility, and options for their prevention and treatment.

An embryo transfer is usually the final step in the process of in vitro fertilization (IVF), where the embryo is transferred to the patient’s uterus. The embryos used in this procedure may either be fresh or thawed (after being frozen).

During IVF, mature eggs are fertilized, either by conventional IVF (insemination) or intracytoplasmic sperm injection (ICSI), after which the resulting embryos are grown in an incubator in the embryology laboratory. An embryo transfer is the procedure whereby one or more of the embryos that has been grown in the lab setting is then transferred from culture media into the patient’s uterus, in the hopes of initiating a pregnancy.  

Fresh embryo transfers are those in which the embryo was fertilized after the ovarian hyperstimulation and egg retrieval process, then transferred in the same cycle. As such, the embryo has never been frozen.ⁱ Alternatively, embryos can be frozen and preserved by a process called cryopreservation, and then stored to be transferred in a subsequent cycle. This is known as a frozen embryo transfer (FET) and requires the cryopreserved embryo to be thawed before transferring into the uterus.ⁱⁱ

Acupuncture is a type of complementary medicine involving the insertion of small needles into specific acupuncture points in the body. It is believed to work by stimulating the nervous system, which can then affect muscles and glands. It has been estimated that over 30 percent of women undergoing fertility treatment will access an alternative medical approach such as acupuncture during their treatment.ⁱ  Fertility acupuncture gained popularity in North American around 2009. Since then, research of varying quality has been conducted to assess the role of acupuncture in both male and female fertility. Its effectiveness in helping improve fertility, especially with respect to IVF success rates, remains unclear.

This article focuses on sperm retrieval procedures, which are procedures that remove sperm from the testicles for the purpose of fertilizing an oocyte (egg). This may be used for men with no sperm in the ejaculate (azoospermia), but that still produce sperm in the testes.

There are two main types of techniques for surgical sperm retrieval: aspiration and extraction. Sperm aspiration involves using a needle to remove (aspirate) sperm from the epididymis or the testes. Sperm extraction takes a sample of the tissue, known as a biopsy, to collect the sperm. There are also different variations or subtypes of these procedures, as well as non-surgical approaches for those with ejaculation limitations.

In order to increase the chances of a successful pregnancy, embryo grading is completed by an embryologist during an in vitro fertilization (IVF) cycle. Assessing embryos for quality at specific stages of embryo development can be a valuable tool in reproductive medicine to help the doctor decide which embryo to transfer first (when there is more than one embryo available for transfer). Understanding what takes place during embryo grading is important, in that it can help patients determine what their next steps in the IVF process might be.

Reproductive immunology is a subspecialty of reproductive medicine that aims to help individuals or couples using assisted reproductive technology (ART) achieve successful pregnancy outcomes. The components of understanding reproductive immunology include how the immune system affects human reproduction, what a reproductive immunologist does, and why a woman may choose to consult with a reproductive immunologist.

Getting pregnant may seem like a simple matter for most people, yet it is far from a simple process and in fact has a number of steps that require just the right timing. Many factors contribute to whether or not an egg will get fertilized, develop into an embryo, and result in a live birth. Whether an individual is trying for pregnancy or thinks she may already be pregnant, understanding the fundamentals of conception can help when seeking medical advice to ensure optimal reproductive health.

Though a vasectomy was formerly considered a permanent sterilization procedure, modern developments have made reversal possible. This article will outline the various procedures for reversing a vasectomy and the likelihood of success in restoring fertility, including a comparison to alternative fertility options.

After an egg retrieval for a fresh cycle, or when contemplating a frozen embryo transfer, women often wonder how many embryos should be placed into the uterus. Usually, single embryo transfer (SET) is promoted, especially if an embryo is genetically tested (undergoes pre-implantation genetic testing, PGT). However, there are cases where a patient may want to transfer two or more embryos. Examining the pros and cons of multiple embryo transfer can help women make an informed decision.

Menopause is a natural process all women will eventually go through as they reach middle age. During menopause, the ovaries stop releasing eggs, menstrual periods become less frequent and eventually cease, and hormones such as estrogen and progesterone decrease. While menopause marks the end of fertility, there is still a chance to become pregnant during menopause - either naturally or through fertility treatments.

Embryo implantation is a complex process and a significant step towards achieving a viable pregnancy. Implantation requires good quality embryos (both genetically and structurally normal), a receptive endometrium, and complex communication between the embryo and the uterine lining.ⁱ The term “implantation failure” describes the lack of a positive pregnancy test (increased human chorionic gonadotropin (hCG) levels) or the lack of an intrauterine pregnancy seen on ultrasound following in vitro fertilization (IVF) and embryo transfer.ⁱⁱ Recurrent implantation failure (RIF) is sometimes called repeated implantation failure, and the terms can be used interchangeably.

For clients going through in vitro fertilization (IVF) or any type of fertility treatment, the associated clinic will build a comprehensive plan to examine all risk factors, health conditions, and reproductive issues that may interfere with the ability to conceive. Much of what is assessed will be associated with the physiological form and function of the reproductive system. The uterine lining is one component of the reproductive system that will be assessed.  

The endometrial lining changes in thickness and appearance in response to the changing hormone levels throughout the menstrual cycle and therefore is used as part of the assessment for how a patient is responding to treatment; as such, it is an important aspect to examine as one part of the reproductive system as a whole.  

A dilation and curettage (D&C) is a surgical procedure that is used to remove tissue from the uterus, and while it is performed for a variety of reasons including diagnostic purposes, it is typically used following a miscarriage or for elective termination of a pregnancy. An understanding of what to expect before, during, and after a D&C is beneficial for navigating this procedure, as well as to learn about potential risks and alternative treatments.

Sperm donation is a process in which a fertile male donates semen (ejaculatory fluid containing sperm) that can be used by an individual or couple wanting to have a baby. An understanding of how sperm donation works, what its success rates are, and why people might opt to use sperm donation are helpful in determining what that type of fertility journey might look like.

Klinefelter syndrome (KS) is a genetic condition whereby a male is born with an extra X chromosome. This condition often impacts fertility in addition to potentially other areas related to health and development, though having this condition does not necessarily mean a person cannot have biological children. By understanding this condition's symptoms, causes, risks, and treatments, those with KS can navigate treatment options.

With regard to in vitro fertilization (IVF), potential success is highly dependent on being able to retrieve enough high-quality eggs that may subsequently go on to produce healthy embryos. Part of that process involves ovarian stimulation. In some cases, fertility doctors will suggest priming protocols. As patients seeking pregnancy review the various IVF protocols suggested, it is important to understand what priming protocol may be best for them. This includes knowing how these protocols can impact reproductive health, what the protocols are used for, what drugs will be required, and what the success rates are.

In vitro fertilization (IVF) is an assisted reproductive technique where sperm and eggs are combined outside the body, and the resulting embryo or embryos are transferred into a uterus (embryo transfer). Performed at a fertility clinic, IVF can help women conceive if they are having trouble doing so, often after completing other, less invasive fertility interventions. It can also be an option for those without fertility issues, including single women, same-sex couples, and those with certain medical conditions such as cancer.  

IVF can be performed using a woman’s own eggs and her partner’s sperm, or with donor eggs or donor sperm. Embryos from IVF, whether donor embryos or created from a woman’s own eggs and partner’s sperm, may be transferred to either the intended parent’s uterus or into a gestational carrier’s (colloquially referred to as a “surrogate”) uterus.  Sometimes the term “IVF” is used to refer to the process of freezing eggs (oocyte cryopreservation) even if fertilization and creation of embryos does not take place.

Pregnancy loss can be devastating under any circumstances, but repeated losses can be particularly difficult to deal with. Recurrent pregnancy loss is defined as having two or more miscarriages. Overall, the risk of pregnancy loss is approximately 25 percent, meaning 1 in 4 recognized pregnancies end in loss. The risk of having two or three pregnancy losses in a row is approximately 2.25 percent and 1 percent respectively. After three consecutive losses, the risk of another pregnancy loss rises to around 40 percent.ⁱ  

In order to understand recurrent pregnancy loss (RPL), it is important to know the potential causes of RPL and what tests and treatments are available to help women experiencing the devastating impact of recurrent miscarriage.

Pelvic inflammatory disease (PID) refers to an infection of the female reproductive organs. PID can occur without symptoms but may also cause mild to severe pelvic pain. In rare cases, it can lead to chronic complications.ⁱ PID is also a risk factor for female infertility. Understanding what causes PID and how it is treated can help women avoid the long-term complications related to this disease.

A miscarriage is the loss of a clinically confirmed pregnancy. For women hoping to conceive, it is important to have accurate information regarding pregnancy loss including prevalence, common causes, warning signs, and management options. An understanding of what to expect after miscarriage and what physical and emotional factors should be considered before trying to conceive again can also be highly beneficial.

Mitochondrial replacement therapy (MRT) is a highly controversial type of therapy used to either prevent genetic disease or support in vitro fertilization (IVF) success when advanced maternal age may be an issue. The therapy is not currently practiced or legal in many countries, including in the United States or Canada, as the practice is considered a very experimental form of genetic modification. Mitochondrial replacement therapy often comes up during online research related to the concept of a “three-person baby.” Several terms are misused in attempting to define mitochondrial replacement, and the procedure itself is often misunderstood. This leads to questions about the idea of a three-person baby, which is technically not an accurate description of mitochondrial replacement therapy.

Asherman’s syndrome is a rare condition defined by the formation of scar tissue in the uterine cavity. It does not have a genetic predisposition and can affect any woman, with a potential impact on fertility. Most cases develop in women who have undergone uterine surgeries. If a woman has received an Asherman’s syndrome diagnosis and is concerned about its impact on her fertility, it is beneficial to understand the symptoms, causes, and range of potential reproductive outcomes.

Varicocele is a fairly common condition affecting the male reproductive system. Many men have varicoceles, but not all varicoceles cause problems. In some men, varicoceles lead to issues such as testicular pain, decreased sperm count, and decreased sperm quality that can affect fertility. For these individuals, varicocele treatment can help.

For some potential parents, the innate immune system—including immune cells called natural killer cells (NK cells)— may play a role in whether or not a pregnancy can be achieved. Knowing what natural killer cells are, the tests for these cells, and possible treatments for high natural killer cell levels can help intended parents better understand their fertility options.

Difficulty with conception can at times be traced to issues within the structure of the reproductive tract, such as the shape of the uterus or blocked fallopian tubes. If a doctor suspects that to be the case, a hysterosalpingogram may be recommended. The hysterosalpingogram is a relatively common diagnostic procedure in reproductive medicine, which gives doctors the ability to see how the uterus and fallopian tubes are shaped.

Endometriosis is a medical condition that affects millions of women worldwide, who can develop endometriosis at an early age. Not only can endometriosis lead to severe pain (including pelvic inflammatory disease) and painful menstrual periods, but it can also negatively affect fertility. Many reproductive-age women who have previously not been formally diagnosed with endometriosis may not realize that they have it until they experience struggles as they attempt to conceive children. In order to recognize and subsequently treat endometriosis, it is critical to first understand the various types of endometriosis symptoms, surgical therapies, and fertility treatments available. In some cases, the most effective treatments are minor surgical procedures. What is most notable is the fact that due to medical advances, there are treatments currently available to effectively manage and treat endometriosis pain.

Monosomy X is a chromosome abnormality that occurs randomly during fertilization and affects only females. Also known as Turner syndrome (TS), this is a genetic condition that if present in a fetus causes significantly increased risk for miscarriage and prenatal complications, like heart defects. After birth, individuals with Turner syndrome are at increased risk for growth issues, learning disabilities, and infertility as adults. Fortunately, with proper early intervention and counseling on reproductive options and risks, women with TS may go on to have successful pregnancies.

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Sperm, or spermatozoa, are the reproductive cells (gamete) of a biological male. The reproductive cell of a biological female is called an oocyte, ovum, or egg. The primary function of sperm is to reach and fuse with an egg. This allows the sperm to deliver male genetic information (DNA) into the egg. In doing so, a zygote (fertilized egg) is formed, which can then go through stages of development to form a fetus. Human DNA is contained within structures called chromosomes, which are found inside the nucleus of every cell. Most human cells are diploid cells, meaning they contain two sets of 23 chromosomes—one set from the sperm and one set from the egg that made them. Sperm and egg cells, however, are haploid cells, and contain a single set of 23 chromosomes. When a sperm fuses with an egg, the newly formed zygote will have two sets of chromosomes, one from the sperm and one from the egg. This is how most human cells end up with a total of 46 chromosomes. Sperm production occurs inside male testes (testicles). Unlike biological females, who are born with all the eggs they will ever produce in their lifetime, biological males start to produce sperm once they reach puberty and will continue making sperm throughout their lifespan. Sperm are also called spermatozoa (plural) or spermatozoon (singular). The term “sperm” can be singular or plural.

A physician may recommend medicated ovulation induction, timed intercourse, intrauterine insemination (IUI), therapeutic donor insemination (TDI), and/or in vitro fertilization (IVF) to assist in becoming pregnant as part of a reproductive medical treatment plan. During treatment, a reproductive endocrinologist (RE) may prescribe ovarian stimulation in order to maximize the number of eggs produced.

Polycystic ovary syndrome (PCOS) is a condition that is often associated with having a negative impact on a woman's ability to conceive. This syndrome is characterized by a range of symptoms, from unwanted hair growth to challenges when trying to conceive, and can be difficult to diagnose and treat.

While both men and women can experience sexual function issues that affect fertility, erectile dysfunction (ED) in men can be one of the more common and problematic. The physical aspect of ED can mean an inability to perform during intercourse and an impeded ability to deliver sperm. However, ED can also be a sign of other health problems and may lead to emotional distress for men, especially when trying to conceive. Understanding what causes ED, who may be most at risk, and how it can be treated are all critical elements for reaching one’s fertility goals.

For women who are thinking about in vitro fertilization (IVF), there is a great deal of information to absorb at once, and much of it can be confusing. In particular, the discussion of an egg (oocyte) vs. follicle involves a significant dive into the mechanisms of IVF. While women may know they are born with all the eggs they will ever have, they may not necessarily understand how their eggs differ from follicles and how these terms are used during IVF. Understanding what each term entails can make the process easier to navigate.

Preimplantation genetic testing (PGT) is the general term for genetic testing performed on embryos produced by women undergoing in vitro fertilization (IVF) before transfer to the uterus. PGT aims to improve the chances of having a successful ongoing pregnancy after embryo transfer. While genetic testing does not impact or change the genetics of an embryo, it gives doctors and prospective parents more information and may help them select the most viable embryos for transfer.

Preimplantation genetic testing (PGT) is the general term for genetic testing performed on embryos produced by in vitro fertilization (IVF) before the embryos are transferred to the uterus. The purpose of PGT is to improve the chances of having a successful embryo transfer.

Genetic testing does not impact or change the genetics of an embryo, but it does give doctors and prospective parents more information and may help them select the most viable embryos for transfer.  

There are three types of PGT: PGT for monogenic disorders (PGT-M), PGT for structural chromosomal rearrangements (PGT-SR), and PGT for aneuploidy (PGT-A). PGT-A is the most routine type performed and as such should be understood by prospective parents.

Egg donation is a process in which a fertile woman donates her eggs (oocytes) to another individual or couple who want to conceive a baby. There are a number of steps involved in not only the decision to use donor eggs, but then to move forward once that decision has been made. For anyone considering using donor eggs, it is important to understand the details around how egg donation works, how to find an egg donor, and what success looks like in this type of fertility journey.

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Despite a commonly held perception, it is not always easy to get pregnant. Individuals can increase their chances of getting pregnant if they know when, how, and how often to have sex. There are also lifestyle tips and tricks that can be helpful in optimizing natural fertility, potentially leading to a positive pregnancy test and a viable birth. Most women who have been trying for only a few months to get pregnant should not be concerned if they have not yet conceived. However, after trying to get pregnant for a lengthier time (more than 6-12 months), it can be helpful to know what some of the indicators are that point towards consulting a health care professional who can provide medical advice regarding fertility issues.

Egg freezing is a fertility preservation technique that was first made available in the late 1990s to women undergoing cancer treatments that could potentially affect their fertility. While this remains an impetus for the procedure, egg freezing is now also used by women to preserve their fertility for a wide range of reasons. Previously considered experimental, egg freezing is currently considered to have minimal risk, and is even covered by some employers in the U.S. through health insurance.

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Read through the different stages of embryo development and what happens after egg retrieval in IVF. Day-by-day outlines and more from researchers in the field.

Chromosomes are made up of DNA and genes that determine multiple aspects of a human’s makeup. Chromosome analyses are often performed in an attempt to give a healthcare provider more insight into a range of issues, from potential genetic conditions to what may be causing recurrent miscarriage. Embryonic and fetal genetic testing may be recommended or pursued for a variety of reasons. Sometimes, individuals or couples have genetic conditions that run in their families, in which case in vitro fertilization (IVF) with preimplantation genetic testing (PGT) can help select embryos that do not carry this condition. In other cases, those attempting to conceive or who have had multiple pregnancy losses may pursue genetic testing of an embryo to help ascertain a cause. Genetic testing can also give an early glimpse into the sex of the fetus as well as whether the fetus has extra/missing chromosomes that could cause conditions such as Down or Turner Syndromes.

Thyroid disorders include hyperthyroidism and hypothyroidism, both of which have to do with thyroid function. Hyperthyroidism, also called overactive thyroid, is when the body produces too much thyroid hormone. Typically, there are changes in weight as well as an increased heartbeat with this thyroid disease, though some people also experience problems with fertility and issues during pregnancy. Treatment options for hyperthyroidism include medication or thyroid surgery.

Approximately 20 to 30 percent of infertility cases are due solely to male infertility, and male infertility contributes to about half of infertility cases overall.ⁱ Sperm defects are a leading cause of male factor infertility; these include a type of sperm DNA damage known as sperm DNA fragmentation (SDF). Doctors and researchers are still learning about SDF, including what causes it, how it can be treated, and how it impacts fertility.

Conceiving through in vitro fertilization (IVF), or other assisted reproductive technology, is a multifaceted process that involves several steps. Once eggs have been retrieved, successfully fertilized, and the embryos have developed, the embryo transfer procedure is planned by the reproductive endocrinologist (REI, also called RE). IVF embryo transfer processes vary depending on factors that include whether fresh or frozen embryos are used and how many embryos are planned for transfer. Successful embryo implantation into the uterine cavity requires careful planning before the actual transfer procedure itself, and possibly a few lifestyle adjustments for the woman during the weeks immediately following the procedure.

Infertility is recognized as a disease by the World Health Organization (WHO), as well as many other professional societies, including the American Medical Association (AMA), the American Society for Reproductive Medicine (ASRM), and the European Society of Human Reproduction and Embryology (ESHRE).^i,ii,iii,iv Estimates of infertility frequency vary worldwide, and even differ depending on the way data is collected. Prevalence is the term used to describe how common a disease/condition is in a particular population. According to the US National Survey of Family Growth, approximately 19.4 percent of married heterosexual women aged 15-49 years have experienced infertility.^v Estimates in the UK population for a similar population were 12.5 percent.^vi Some studies indicate that the prevalence of male infertility is approximately 10-15 percent, but these estimates may not be accurate due to the lack of good quality evidence.^vii

Because hypothyroidism can play a role in infertility, a woman going through in vitro fertilization (IVF) should be aware of the symptoms of hypothyroidism and possible treatments.

ERA, which stands for endometrial receptivity analysis (previously known as endometrial receptivity array), is a diagnostic tool intended to determine how “receptive” the maternal uterine lining (endometrium) is towards implantation of a transferred embryo.^i,ii ERA evaluates the expression of genes involved in endometrial receptivity during the window of implantation (WOI). These results are then used to determine whether a patient should have a frozen embryo transfer with standard timing, or if timing needs to be adjusted to account for a displaced WOI, a process known as personalized embryo transfer (pET).

Individuals who are transgender or transitioning face unique issues regarding fertility, family building, and fertility preservation. The term transgender describes individuals who do not identify with the sex they were assigned at birth. Gender identity is complex and exists on a spectrum. While some transgender people identify with a gender different than the sex they were assigned at birth (often referred to as genetic or biological sex), others do not identify as either of the traditional binary genders.  

Transgender men are individuals who were assigned female sex at birth but identify as male, while transgender women are those who were assigned male sex at birth and identify as female. Some transgender individuals prefer to be identified only as men/male or women/female, dropping the term transgender. Others prefer the terms trans man or trans woman. In this article we will discuss options for creating a family as a transgender individual as well as for those who are undergoing gender transition, and will use trans or transgender terminology for conciseness even as we recognize the differences in preferred language. We will also discuss pregnancy, the delivery process, and aspects of the postpartum course for these individuals.  

Transgender parenthood is fairly common. According to the U.S. Transgender Population Health Survey, 19 percent of transgender respondents were parents.ⁱ

Preimplantation genetic testing (PGT) is the general term for genetic testing performed on embryos produced by in vitro fertilization (IVF) before the embryos are transferred to the uterus. The purpose of PGT is to improve the chances of having a successful embryo transfer.

Genetic testing does not impact or change the genetics of an embryo, but it does give doctors and prospective parents more information and may help them select the most viable embryos for transfer.  

There are three types of PGT: PGT for monogenic disorders (PGT-M), PGT for structural chromosomal rearrangements (PGT-SR), and PGT for aneuploidy (PGT-A). PGT-A is the most routine type performed and as such should be understood by prospective parents.

After an egg retrieval for a fresh cycle, or when contemplating a frozen embryo transfer, women often wonder how many embryos should be placed into the uterus. Usually, single embryo transfer (SET) is promoted, especially if an embryo is genetically tested (undergoes pre-implantation genetic testing, PGT). However, there are cases where a patient may want to transfer two or more embryos. Examining the pros and cons of multiple embryo transfer can help women make an informed decision.

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