Assisted Reproductive Technologies
Definition
Assisted reproductive technology (ART)
Consists of medical procedures used primarily to address infertility.
e.g. in vitro fertilization
intracytoplasmic sperm injection (ICSI)
cryopreservation of gametes or embryos
and/or the use of fertility medication.
Some forms of ART may be used with regard to fertile couples for genetic purpos.
ART may also be used in surrogacy arrangements
With ART, the process of sexual intercourse is bypassed and fertilization of the oocytes occurs in the laboratory environment (i.e., in vitro fertilization)
ART includes 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.
ART also excludes artificial insemination and includes only procedures where oocytes are handled.
Procedures
Ovulation induction is stimulation of the development of ovarian follicles by fertility medication to reverse anovulation or oligoovulation.
In vitro fertilization
Steps of IVF Treatment
In vitro fertilization is the technique of letting fertilization of the male and female gametes (sperm and egg) occur outside the female body.
Transvaginal ovum retrieval : 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 : one or several embryos are placed into the uterus of the female with the intent to establish a pregnancy.
Intracytoplasmic sperm injection (ICSI)
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.
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.
Pre-implantation genetic diagnosis
Conducted on embryos prior to implantation (as a form of embryo profiling), and sometimes even of oocytes prior to fertilization.
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.
Sex selection is the attempt to control the sex of offspring to achieve a desired sex. 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.
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.
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.
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