Human Reproduction Glossary

Abortion: Termination of a pregnancy before 22 weeks of gestation.

Blastocyst: An embryo on the fifth day of development.

Canceled cycles: Any ART cycle that is discontinued before an egg is retrieved, or any frozen embryo transfer cycle in which the embryo transfer is not performed. Cycles may be canceled for several reasons: follicles may fail to develop; the patient may become ill; or the patient may choose to discontinue treatment for any reason.

Frozen embryo cycle: An assisted reproduction cycle in which a frozen embryo is thawed and transferred to the uterus.

Egg donation cycle: A cycle in which an embryo is created using an egg from a donor and transferred to a recipient. The donor relinquishes all parental rights regarding any resulting pregnancy or child.

ART cycles: The process in which the ovaries are stimulated and monitored for the purpose of performing assisted reproductive technology (ART), intrauterine insemination, timed intercourse, or in vitro fertilization. Frozen embryo transfer cycles are also included. The cycle begins when the patient starts taking medication.

Cryopreservation: The process of freezing surplus embryos, eggs, or sperm for potential future use.

Ovulatory dysfunction: A diagnosis in patients who do not ovulate normally. One of the most common causes is polycystic ovary syndrome (PCOS).

Adverse outcomes: A pregnancy does not necessarily result in a live birth. Adverse outcomes may include pregnancy loss, miscarriage, intrauterine fetal death, multiple pregnancy, and preterm birth.

Embryo: An egg after it has been fertilized by a sperm cell and has undergone one or more cell divisions.

Endometrium: The tissue that lines the inside of the uterus.

Endometriosis: A medical condition in which tissue similar to the tissue that lines the uterus grows outside the uterus. This condition may interfere with fertilization and implantation.

Sperm: The male reproductive cell.

Ovarian stimulation: The use of oral or injectable medications to stimulate the development of follicles and eggs.

Female factor: Any female-related cause of infertility that prevents or reduces the likelihood of pregnancy.

Male factor: Any male-related cause of infertility, ranging from a low sperm count to conditions that make it difficult for sperm to fertilize an egg under normal circumstances.

Tubal factor: A type of infertility in which the fallopian tubes are blocked or damaged, making it difficult for sperm to reach and fertilize the egg.

Ovarian factor: Any condition that prevents or interferes with the development or release of an egg.

Uterine factor: A functional or structural disorder of the uterus that results in reduced fertility.

Fertilization: The penetration of an egg by a sperm cell, resulting in the combination of genetic material that will develop into an embryo.

In Vitro Fertilization (IVF): A procedure that involves retrieving eggs from the ovaries and fertilizing them outside the body. The resulting embryos are transferred into the uterus through the cervix.

Fetus: The developing conceptus from the eighth week of gestation until birth.

Follicle: A structure within the ovary that contains a developing egg and is involved in hormone production.

Gamete: A reproductive cell. The male gamete is the sperm cell, and the female gamete is the egg.

Gestation: The period from embryo implantation until birth.

Gestational surrogacy: An arrangement in which a woman agrees to carry a pregnancy using an embryo created for another couple and is contractually required to transfer parental responsibility for the child to the biological parents after birth.

Multiple pregnancy: A pregnancy in which two or more fetal heartbeats are detected during the first trimester.

Ectopic pregnancy: A pregnancy in which the fertilized egg implants outside the uterus. It most commonly occurs in a fallopian tube and, more rarely, in the ovary or abdominal cavity. This is a potentially dangerous condition that requires medical treatment.

Clinical pregnancy: A pregnancy in which a gestational sac is visualized by ultrasound.

Chemical pregnancy: A pregnancy in which the pregnancy test, based on β-hCG levels, is positive.

Hysteroscopy: A procedure in which a small fiber-optic instrument is inserted into the uterus to diagnose abnormalities of the endometrium.

ICSI: A procedure in which a single sperm cell is injected directly into an egg. It is most commonly used when there is a male-factor fertility issue.

Ovulation induction: A phase of fertility treatment in which medications are used to stimulate follicular development, beginning early in the menstrual cycle and continuing through the fertile period. The goal is to obtain the greatest number of eggs considered safe for the patient's health, so they can be fertilized with sperm for an immediate or future pregnancy, including through cryopreservation.

Unexplained infertility: A type of infertility in which no identifiable female or male cause is found.

Intrauterine insemination (IUI): A medical procedure in which prepared sperm is placed directly into the uterus, usually after ovulation induction, to facilitate fertilization.

Laparoscopy: A surgical procedure in which a small incision is made near the navel to allow visualization of the pelvis using a fiber-optic instrument connected to a video system.

Ovarian monitoring: A series of ultrasound examinations and/or blood or urine tests performed to evaluate the development of ovarian follicles.

Morula: An embryo consisting of more than 12 cells, a stage generally reached around the fourth day of embryonic development.

Live birth: A delivery in which one or more babies show any sign of life.

Egg or oocyte: The female reproductive cell located inside an ovarian follicle.

Fresh eggs, sperm, or embryos: Eggs, sperm, or embryos that have not been frozen. Fresh embryos may be created using previously frozen eggs or sperm.

PGD (Preimplantation Genetic Diagnosis): A technique that combines advances in molecular biology and assisted reproductive technology. A small number of cells are removed from the embryo before transfer to identify genetic disorders. It is particularly indicated when there is a high risk of inherited genetic disease.

Egg retrieval: A procedure to collect eggs from the ovarian follicles, generally performed under sedation and after fasting.

Ovarian reserve: The estimated number of eggs remaining in the ovaries until menopause, assessed through hormone testing and ultrasound. A decrease in ovarian reserve means a reduced ability of the ovaries to produce eggs. Several factors may contribute to diminished ovarian reserve, including genetic factors, certain diseases such as mumps, ovarian surgery, and maternal age.

Gestational sac: A fluid-filled structure that develops inside the uterus during the early stages of pregnancy. In a normally developing pregnancy, the gestational sac will eventually contain the developing fetus.

Semen: Fluid produced by the male reproductive glands that contains sperm cells.

SBRH, SBRA, and the LARA Network: Professional societies whose members represent a large proportion of assisted reproduction clinics in Brazil.

Pregnancy rate: A measure of ART success defined by the proportion of patients who undergo a procedure and subsequently have a positive pregnancy test.

Implantation rate: A measure of ART success based on assisted reproduction cycles resulting in a clinical pregnancy. It is defined by the relationship between the number of embryos transferred and the number of fetal heartbeats detected by ultrasound.

Assisted Reproductive Technology (ART): Treatments or procedures involving medications that stimulate egg production and ultrasound monitoring with the goal of obtaining eggs for fertilization with sperm. These treatments may be divided into low- and high-complexity procedures. In low-complexity treatments, fertilization occurs inside the fallopian tube; examples include intrauterine insemination and timed intercourse. In high-complexity treatments, fertilization takes place in the laboratory, followed by transfer of the resulting embryos into the uterus.

Embryo transfer: The placement of an embryo into the uterus after IVF. It generally takes place on the third or fifth day after egg retrieval and is typically performed with a full bladder.

FET: Frozen embryo transfer.

Ultrasound: An imaging examination used to visualize ovarian follicles, the gestational sac, or the fetus.