Assisted reproductive technology (ART) includes medical procedures used primarily to address infertility. This subject involves procedures such as in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and cryopreservation of gametes and embryos, and the use of fertility medication. When used to address infertility, ART may also be referred to as fertility treatment. ART primarily belongs to the field of reproductive endocrinology and infertility. Some forms of ART may be used by fertile couples for genetic purposes (see preimplantation genetic diagnosis). ART may also be used in surrogacy arrangements, although not all surrogacy arrangements involve ART.
Procedures General With ART, the process of sexual intercourse is bypassed and fertilization of the oocyte occurs in the laboratory environment (i.e., in vitro fertilization).
In the US, the Centers for Disease Control and Prevention (CDC) defines ART to include "all fertility treatments in which both eggs and sperm are handled. In general, ART procedures involve surgically removing eggs from a woman's ovaries, combining them with sperm in the laboratory, and returning them to the woman's body or donating them to another woman." According to CDC, "they do not include treatments in which only sperm are handled (i.e., intrauterine—or artificial—insemination) or procedures in which a woman takes medicine only to stimulate egg production without the intention of having eggs retrieved."
In Europe, ART also excludes artificial insemination and includes only procedures where oocytes are handled.
The World Health Organization (WHO) also defines ART this way.
Ovulation induction
Ovulation induction is usually used in the sense of stimulation of the development of ovarian folliclesOvulation Problems and Infertility: Treatment of ovulation problems with Clomid and other fertility drugs. Advanced Fertility Center of Chicago. Gurnee & Crystal Lake, Illinois. Retrieved on Mars 7, 2010Flinders reproductive medicine > Ovulation Induction Retrieved on Mars 7, 2010fertilityLifeLines > Ovulation Induction Retrieved on Mars 7, 2010 by fertility medication to reverse anovulation or oligoovulation. These medications are given by injection for 8 to 14 days. A health care provider closely monitors the development of the eggs using transvaginal ultrasound and blood tests to assess follicle growth and estrogen production by the ovaries. When follicles have reached an adequate size and the eggs are mature enough, an injection of the hormone hCG initiates the ovulation process. Egg retrieval should occur 36 hours before ovulation.
In vitro fertilization
In vitro fertilization is the technique of letting fertilization of the male and female gametes (sperm and egg) occur outside the female body.
Techniques usually used in in vitro fertilization include: Transvaginal ovum retrieval (OVR) is the process whereby a small needle is inserted through the back of the vagina and guided via ultrasound into the ovarian follicles to collect the fluid that contains the eggs. Embryo transfer is the step in the process whereby one or several embryos are placed into the uterus of the female with the intent to establish a pregnancy. Less commonly used techniques in in vitro fertilization are: Assisted zona hatching (AZH) is performed shortly before the embryo is transferred to the uterus. A small opening is made in the outer layer surrounding the egg in order to help the embryo hatch out and aid in the implantation process of the growing embryo. Intracytoplasmic sperm injection (ICSI) is beneficial in the case of male factor infertility where sperm counts are very low or failed fertilization occurred with previous IVF attempt(s). The ICSI procedure involves a single sperm carefully injected into the center of an egg using a microneedle. With ICSI, only one sperm per egg is needed. Without ICSI, you need between 50,000 and 100,000. This method is also sometimes employed when donor sperm is used. Autologous endometrial coculture is a possible treatment for patients who have failed previous IVF attempts or who have poor embryo quality. The patient's fertilized eggs are placed on top of a layer of cells from the patient's own uterine lining, creating a more natural environment for embryo development. In zygote intrafallopian transfer (ZIFT), egg cells are removed from the woman's ovaries and fertilized in the laboratory; the resulting zygote is then placed into the fallopian tube. Cytoplasmic transfer is the technique in which the contents of a fertile egg from a donor are injected into the infertile egg of the patient along with the sperm. Egg donors are resources for women with no eggs due to surgery, chemotherapy, or genetic causes; or with poor egg quality, previously unsuccessful IVF cycles, or advanced maternal age. In the egg donor process, eggs are retrieved from a donor's ovaries, fertilized in the laboratory with the sperm from the recipient's partner, and the resulting healthy embryos are returned to the recipient's uterus. Sperm donation may provide the source for the sperm used in IVF procedures where the male partner produces no sperm or has an inheritable disease, or where the woman being treated has no male partner. Preimplantation genetic diagnosis (PGD) involves the use of genetic screening mechanisms such as fluorescent in-situ hybridization (FISH) or comparative genomic hybridization (CGH) to help identify genetically abnormal embryos and improve healthy outcomes. Embryo splitting can be used for twinning to increase the number of available embryos.
Pre-implantation genetic diagnosis A pre-implantation genetic diagnosis procedure may be conducted on embryos before implantation (as a form of embryo profiling), and sometimes even of oocytes before fertilization. PGD is considered similar to prenatal diagnosis. PGD is an adjunct to ART procedures and requires in vitro fertilization to obtain oocytes or embryos for evaluation. Embryos are generally obtained through blastomere or blastocyst biopsy. The latter technique has proved to be less deleterious for the embryo; it is advisable to perform the biopsy around day 5 or 6 of development. Sex selection is the attempt to control the sex of offspring to achieve a desired sex in case of X chromosome-linked diseases. It can be accomplished in several ways, both pre- and post-implantation of an embryo, as well as at birth. Pre-implantation techniques include PGD, but also sperm sorting.
Others Other assisted reproduction techniques include: Mitochondrial replacement therapy (MRT, sometimes called mitochondrial donation) is the replacement of mitochondria in one or more cells to prevent or ameliorate disease. MRT originated as a special form of IVF in which some or all of the future baby's mitochondrial DNA comes from a third party. This technique is used in cases when mothers carry genes for mitochondrial diseases. The therapy is approved for use in the United Kingdom. Index page with links to summaries including one page summary flyer . In gamete intrafallopian transfer (GIFT), a mixture of sperm and eggs is placed directly into a woman's fallopian tubes using laparoscopy following a transvaginal ovum retrieval. Reproductive surgery, treating e.g. fallopian tube obstruction and vas deferens obstruction, or reversing a vasectomy by a reverse vasectomy. In surgical sperm retrieval (SSR), the reproductive urologist obtains sperm from the vas deferens, epididymis, or directly from the testis in a short outpatient procedure. By cryopreservation, eggs, sperm, and reproductive tissue can be preserved for later IVF.
Risks The most common treatment-related complication of ART is multiple pregnancies, which carry higher risks of adverse outcomes, including preterm birth and low birth weight. Best practices for IVF have been revised to discourage the transfer of multiple embryos in favor of elective single embryo transfer (eSET) policies. This has led to reductions in the global incidence of both multiple pregnancies and pre-term births resulting from IVF. ART also carries a risk for heterotopic pregnancy (simultaneous intrauterine and extrauterine pregnancy).
Those using artificial reproductive technology are at an increased risk for medical complications that can affect both the mother and baby, including hypertension, gestational diabetes mellitus, pre-eclampsia, placental disorders, pre-term delivery, and caesarean delivery. Evidence suggests that women who conceive using ART often have preexisting underlying risk factors that increase their likelihood of developing cardiovascular diseases and vascular complications (acute kidney injury, arrhythmia, ischemic stroke, and venous thromboembolism). Medical complications are associated with significant economic and clinical impacts for both maternal and neonatal health services.
The vast majority of IVF-conceived infants are free from birth defects. However, a meta-analysis of studies from multiple countries indicates that children conceived via assisted reproductive technology do have a slightly higher risk of birth defects (1.22 times) compared to children born after natural pregnancy. Cardiovascular defects were the most strongly associated type of birth defect. Orofacial, central nervous system, urogenital and musculoskeletal defects were also more likely to occur.
The reasons for increased risk of birth defects are unclear. There may be risks associated with ICSI and IVF-ET operating procedures. There may also be contributing underlying factors among patients, such as parental age, obesity, parental fertility, gamete quality, or exposure to environmental pollution.
Several meta-analyses have indicated that children born as a result of IVF are roughly twice as likely to have cerebral palsy than those conceived naturally. When the occurrence of multiple births is taken into account, and single-pregnancy outcomes are compared, the increased risk of cerebral palsy decreases but is still present.
De novo mutations (DNMs) are spontaneous genetic alterations that occur in the germline or during early embryonic development. The frequency of de novo mutations increases progressively with the age of parents at the time of conception, with an increase of approximately 1.35 to 1.5 DNMs for each additional year of paternal age and a smaller increase of 0.24 to 0.42 for each additional year of maternal age. Sperm DNA damage may therefore be a key factor affecting the development of early embryos. Oocytes are capable of efficient DNA repair, while sperm lack this ability. Studies of the possible effects of assisted reproductive technology on the frequency of de novo mutations have yielded conflicting results. Some studies report negative effects of ART while others find no effects. The impact of ART on the likelihood of DNMs may be less important than those due to parental aging and environmental factors.
Pregnancies involving oocyte donation or sperm donation may have lower risks. Genetic screening is normally performed to exclude donors with chromosome abnormalities, and the age of donors is often restricted.
A 2025 meta-analysis did not find evidence to link assisted reproductive technology (ART) with childhood cancer. A landmark paper by Jacques Balayla et al. reported that infants born after ART have similar neurodevelopment to infants born after natural conception.Balayla, Jacques, Odile Sheehy, William D. Fraser, Jean R. Séguin, Jacquetta Trasler, Patricia Monnier, Andrea A. MacLeod, Marie-Noëlle Simard, Gina Muckle, and Anick Bérard. "Neurodevelopmental Outcomes After Assisted Reproductive Technologies." Obstetrics & Gynecology (2017).