An ectopic pregnancy located in the peritoneal cavity, or abdomen, usually having undergone implantation in the fallopian tube as a tubal pregnancy, then continuing to grow after the tube eventually ruptures. Rare in countries with ready access to medical care, as considerable symptoms have to have been ignored (and survived) during the tubal rupture part of the process. The fetus can grow almost to full term, but delivery of a live baby (delivered by operation) has never been reported.

An estimate of the percentage of spermatozoa that have an abnormal shape of the head, mid-piece or tail. Part of the routine sperm count.

A departure from what's normal -- in a more or less exact medical sense. An abnormality can be quantitative (or measurable with a number), qualitative (not measurable but still apparent or obvious), or a matter of timing (temporal). Statistically, we define an abnormality as signifying either a measurement or a yes-or-no quality that is outside what, for example, 90 or 95 or 99 percent of the population exhibits (see also statistical significance). It's a word without added value, unlike defect, for example, which has a negative connotation. So if you want to avoid a gratuitous, negative effect it's preferable, using this example, to say "birth abnormality" instead of "birth defect"

Strictly, synonymous with spontaneous abortion or miscarriage. Loosely, an induced abortion for early termination of pregnancy.

Synonymous with sterility, or 100 percent infertility; also called complete infertility.

Your actual chance of having something or being affected by something (so it does not usually mean "absolutely" in the sense of "one hundred percent", as in absolute infertility). Usually given as a ratio, proportion or percentage: for example, the (absolute) risk of having at least some visible endometriosis for a woman in her 40s is about 20 in 100, or 20 percent; the chance or the risk of pregnancy each month for a normal young couple (normal fecundability) is also about 20 percent, usually expressed as 0.2 (i.e. as a proportion); the risk of a woman developing cancer of the ovaries by the time she reaches her seventies, in North America, Europe or Australia, is about 1-in-90 (or about 1.1%).

The sequel to responsibility, in which responsibility for the making of a decision continues to rest with the decision-maker as the effects or consequences from the decision unfold.

Consider it to be the mature spermatozoon's crash-helmet, present over the sperm head until the successful sperm binds to the coating of the egg known as the zona pellucida; imagine it to be like a balloon into which your fist is pushed (the fist being the sperm's head) -- bursting only when bound like Velcro to the zona (see acrosome reaction).

If the acrosome is a balloon-like crash-helmet for the mature spermatozoon, the acrosome reaction is the bursting of that balloon, releasing enzymes that digest a path for the highly motile sperm (after capacitation) to push through the zona pellucida into the perivitelline space, where it can directly fertilise the egg.

Medically, means sudden and quick. An acute inflammation is usually red, tender and may form pus. Opposite to chronic.

The glandular part of the pituitary gland, lying toward the front, so in medical speak called the anterior pituitary. Produces follicle stimulating hormone, luteinising hormone and prolactin. Other hormones include hormones that: (1) cause normal childhood growth (growth hormone), (2) drive the thyroid gland (thyroid stimulating hormone, or TSH), and (3) drive the adrenal gland (adrenocorticotropic hormone, or ACTH). See also hypothalamus and neurohypophysis.

An abnormal condition of the uterus in which glands from the endometrium grow into the muscle of the wall of the uterus (the myometrium), causing local or general enlargement of the uterus, pain with periods, and perhaps heavier periods. A localised area of adenomyosis is called an adenomyoma and can be hard to distinguish from a fibroid on transvaginal ultrasound, although an increase in the serum CA 125 antigen level can point to the correct diagnosis. Unlike a fibroid it is not easily removed at surgery, because it's not clearly separable from surrounding tissue. There's no satisfactory long term treatment for adenomyosis: hysterectomy may be chosen if symptoms are bad enough. GnRH-agonists give just temporary relief.

Scar tissue, in particular between the serosa (surface lining) of abdominal or pelvic organs in the peritoneal cavity, which can interfere with the access the fallopian tube has to the ovary at ovulation. Adhesions can be thin and transparent (sometimes called filmy or Grade 1), a little like thin plastic wrap; thicker, and containing more scar tissue and blood vessels (Grade 2); or thick, dense and tough (Grade 3). Adhesions are caused by infections, endometriosis or a previous operation. Not all adhesions are important: it depends on where they are. See also intrauterine adhesions. The treatment of adhesions requires microsurgery, and there are special steps that have to be taken to stop them coming back again.

A paired gland lying above each kidney, responsible for the essential hormone cortisol. Equally important with the ovaries in producing androgens in women.

Artificial insemination, donor (or assisted insemination, donor);

Acquired immune deficiency syndrome.

Because genes come in pairs, one on each of the chromosomes that make up a chromosome pair, the two genes of the pair are not always identical. The manydifferent forms that a particular gene can take (and still function, for better or for worse, as a gene within that gene's job description) are referred to as its alleles. If the alleles are identical, you are homozygous for that gene; if they are not, you are heterozygous. Abnormal alleles cause genetic disease or disability: if one allele is enough to cause abnormality then the gene is dominant (inherited with dominant inheritance) and the abnormality is present in the heterozygous and the homozygous state; if two alleles are needed to cause abnormality, then the gene is recessive (inherited with recessive inheritance) and the abnormality is present in the homozygous state and in a state where the two alleles are different but both are harmful (called compound heterozygosity. In the case of alleles found on X-chromosomes (see sex chromosome) but not on Y-chromosomes, which are smaller, a recessive gene will be unopposed in males (and so will act as a dominant gene), whereas female carriers of the allele will be unaffected except in the extremely unlikely event that they inherit (or gain by mutation) a second abnormal allele; this mode of inheritance is called sex-linked recessive inheritance.

A form of albumin (a protein in the blood) produced only by the fetus, but crosses the placenta and so is detectable in the mother's blood (measured with a serum alpha fetoprotein, as well as being usefully measured in amniotic fluid obtained by amniocentesis. Detectable in higher than usual concentration with certain open abnormalities involving the fetus's brain and spinal cord (namely anencephaly and spina bifida). Present in lower than usual concentration when there is a trisomyin the fetus, such as Down syndrome (or trisomy 21), trisomy 18 or possibly Klinefelter syndrome -- screening for all of which can be done with a triple test.

Absent menstrual periods, either because of absent ovulation (anovulation) or because of absence of, destruction of, or obstruction to the menstrual flow from the uterus, such as with intrauterine adhesions (when it's known as Asherman's syndrome).

Sampling the fluid from the amniotic cavity after about 14 or 15 weeks of pregnancy. Cells from the fetus can be set up in culture for a karyotype, or for special diagnoses can be examined more quickly by fluorescent in situ hybridisation (FISH), comparative genomic hybridisation (CGH) or by polymerase chain reaction (PCR). Other substances in the amniotic fluid (such as alpha fetoprotein, or AFP) can be measured to indicate whether the fetus is normal or not.

The membrane and cavity that encloses the developing embryo and fetus in fluid (essential for all vertebrates that reproduce out of the sea), cushioning the embryo and fetus from the effects of pressure. Unlike the chorion, contains cells that originate from the fetus itself.

Cavity enclosed by the amnion, which grows from the embryo within the gestational sac, gradually catching up with it in size by about 14 weeks, when the amnion and chorion fuse, and after which amniocentesis becomes practicable.

The fluid in the amniotic cavity, or gestational sac, which contains cells derived from the fetus. Sampled with amniocentesis.

The wide outer part of the fallopian tube, lying between the fimbrial end and the narrow isthmus.

The point at which the wide ampulla of the fallopian tube meets the narrow isthmus. The place where fertilisation of the egg by a sperm cell normally takes place.

Complete or partial resistance to the action of androgens in the body's tissues. Prevents or limits the development of male characteristics in the developing fetus, resulting in intersex.

Male sex hormones, including testosterone (the main androgen circulating in the blood in men and in women) and androstenedione (which is weaker). Produced in women more or less equally by the adrenal glands and the ovaries (in thecal cells and hilus cells). Produced in much greater quantity in men by the testes (testicles).

A weak androgen, produced in women by thecal cells in the ovary and by the adrenal glands.

The gain or loss of one or more chromosomes at meiosis, including trisomy (47 chromosomes) and monosomy (45 chromosomes). Caused by chromosomal nondisjunction.

Antinuclear factor.

When implantation occurs in one or other outer angle of the triangular cavity uterus (that is, out to one side, very close to where the fallopian tubes enter the endometrial cavity). A miscarriage is common. Rupture of the uterus has been reported.

A protein molecule with anticoagulant properties bound to chorionic villi, responsible for assisting maternal blood to circulate in the placenta.

Distinguishable from an abnormality in that the outcome in the case of an anomaly might not lead to disease or disability. An anomalous kidney, for example, is in the wrong place but does its job perfectly well. The distinction between an anomaly and an abnormality, however, is loose and is not strictly observed.

"Anorexia" means a profound loss of appetite, followed by loss of weight; "nervosa" means that there is a nervous or mental basis for the state, in this case a belief by the person affected, and contrary to the perception of others, that she (very rarely he) is overweight. She stops eating, may induce vomiting, and uses laxatives to keep the intestines empty and the stomach flat. The menstrual periods stop (there is amenorrhea for two reasons: the weight loss and the underlying mental disturbance, both of which cause hypothalamic anovulation. Medical complications from induced vomiting and laxative abuse can be serious, occasionally fatal. Treatment, which includes psychological and psychiatric counseling, is difficult and is not always completely accomplished. It's a condition chiefly of adolescent girls; the younger the patient the better the chance of cure. For fertility, ovulation induction as often required.

Absence of ovulation

Menstrual cycles caused by ovarian activity (or ovarian cycles) not accompanied by ovulation. The serum progesterone stays low, whereas some development of tertiary follicles and production of estradiol takes place. See also anovulatory dysfunctional uterine bleeding.

Irregular and generally heavy bleeding caused by anovulatory cycles. The underlying causes and how to prevent the sometimes harmful consequences, including endometrial hyperplasia.

The GnRH-antagonist ganirelix made by Organon. Called Orgalutran outside the US.

A forward angle of the fundus of the uterus in relation to the direction of the cervix. Usually only occurs when the uterus is anteverted. Opposite to retroflexed.

Refers to the (normal) position of the uterus, meaning that it is tilted forward in relation to the direction of the vagina. Opposite to retroverted.

A protein of the immune system capable of binding to an antigen. The binding is specific to the particular antigen and often neutralises its effects. Antibodies, or immunoglobulins, account for almost half of the proteins circulating in the blood (most of the rest being albumin).

(ACA) An antibody that acts against components in the cell membranes (membranes that holds a cell together as well as surrounding some internal cell structures). Looked for in the blood (we ask for a serum anticardiolipin as a possible immune cause of recurrent miscarriages. Intriguingly, the membrane that contains most cardiolipin is the membrane surrounding the mitochondrion (malfunction of which is implicated in causing miscarriage, although how (or if) the antibody might get to the mitochondria is not known.

Anything that stimulates the production of a specific antibody by the immune system.

A hormone produced by the Sertoli cells of the testes in a male embryo to suppress the development of the Mullerian ducts.

Synonym: antinuclear factor. An antibody directed at phosphate-containing fatty components of cell membranes, such as cardiolipin (see anticardiolipin antibody). Low levels are probably common and harmless; in higher levels they can cause disease, particularly during pregnancy, including thrombosis and miscarriage.

Means the same as sperm antibodies

A tertiary follicle

A fluid-filled space between the follicle cells, the development of which marks the transformation of a tertiary follicle from a secondary follicle. Composes the bulk of the mature, preovulatory follicle (sometimes called the Graafian follicle) and very obvious on transvaginal ultrasound scanning during monitoring of follicular development as dark, "echolucent" spaces within the ovary.

The word for what scientists call programmed cell death, or cellular suicide. This is a normal -- rather altruistic! -- thing for a cell to do, as it purposefully switches on some special genes that then alter its metabolism to dismantle itself and die, for the greater good of the tissue or organ that it's a part of. Pathologists distinguish apoptosis from necrosis. Examples of apoptosis include follicular atresia.

Literally, noninfective death of the bone tissue of the top end of the thigh bone (where it forms the hip joint). A rare but serious complication from continued high dosages of cortisone-like drugs, including cortisone, prednisone and prednisolone, sometimes used for treating, for example, sperm antibodies.

The opposite to sexual reproduction.

The combination of intrauterine adhesions and amenorrhea.

An absence of semen despite male orgasm; thus, different to azoospermia, an absence of sperm.

A group of medical treatments ranging from assisted insemination (IUI) to in vitro fertilisation (IVF), including its technical variants (such as GIFT, ICSI and PGD, and with the following common characteristics: (1) they are aimed at increasing the chance of pregnancy each month, thus overcoming the medical disability of infertility; (2) there is little or no "spillover" of therapeutic effect beyond the cycle or month in which treatment is invoked; and (3) there is some form of procedural intervention, with sperm, eggs or embryos spending some time outside of the body. It's not necessary for there to be stimulation of the ovaries (superovulation) for multiple development of follicles.

An in vitro fertilisation manipulation in which a small opening is made in the zona pellucida of the early embryo to help the blastocyst emerge prior to implantation. Formerly carried out by judicious use of an enzyme to dissolve the zona (but risking damage to the embryo), leading IVF programs use a microlaser.

Insemination, or injection of semen or prepared spermatozoa, into the vagina, cervix, uterus (intrauterine insemination) or fallopian tube, to treat infertility. A basic form of assisted conception. The husband's (or male partner's) sperm (AIH) or donated sperm (DI) can be used.

(AIH), or assisted insemination in which the semen from the husband or male partner is used.

(ART) The term is essentially synonymous with assisted conception, but tends to emphasise the technology instead of the medical help to which the technology is put.

Process by which a tissue stops growing, loses its function and degenerates. Synonymous with atrophy.

A tertiary follicle that: (1) is no longer growing; (2) is no longer secreting estradiol; and (3) no longer contains a healthy oocyte, or egg.

Literally, an absence of nutrition, but in particular the result of such lack in a tissue, which shrinks and loses its normal function. For examples, see endometrial atrophy and follicular atresia. Sometimes the end-result of necrosis.

An ethical principle in which value is given to maximising an individual's contribution to the making of decisions that affect them. Can be overdone by abrogating professional responsibility through misuse of informed consent.

A chromosome other than one of the sex chromosomes (which are X or Y). Numbered from 1 to 22, and displayed in a karyotype.

A complete absence of sperm (spermatozoa) in the semen. Detectable only by performing a sperm count, as semen looks the same whether it contains sperm or not. Due either to an obstruction (usually in the epididymis or vas deferens), and called obstructive azoospermia, or to failure of sperm to form or to mature in the testis (called maturation arrest). See also spermatogenesis and testicular sperm extraction (TESE).