A mucus-like protein produced in some circumstances by surface cells of tissues derived from the Mullerian ducts. Its function is obscure but measurement as serum CA125 antigen can be useful in diagnosing adenomyosis, endometriosis and some cancers of the ovary.

imilar to bromocriptine, but more potent and with fewer side effects; used once or twice weekly to lower production of prolactin in hyperprolactinemia. Not yet approved for infertility treatment, but no adverse fetal effects have been reported when used for ovulation induction.

English spelling for cecum.

An invisible change mature sperm (spermatozoa) undergo to acquire accelerated movement and the ability to undergo the acrosome reaction. Brought about naturally when sperm swim up through the uterus and fallopian tubes, or brought about in the laboratory by spinning and washing the sperm through a series of solutions (in preparation for assisted conception).

A special form of x-ray taken with the person enveloped in the x-ray apparatus, which builds up a particularly good image of any cross-section or series of cross-sections through the body, by a process of computed tomography. Particularly useful for investigation of the anatomy of the pituitary gland and hypothalamus when a tumor is suspected or needs to be excluded. More widely available than an MRI scan, which can give even clearer results.

Short for electrocautery, or diathermy.

Congenital bilateral absence of the vas deferens.

A defect of intestinal absorption caused by abnormal sensitivity to gluten in the diet that can first manifest with recurrent miscarriage or unexplained infertility, despite an absence of diarrhea or other disturbances of bowel function. Diagnosis is suggested by serum antigliadin antibodies and serum tissue transglutaminase (or endomysial) antibodies, but requires biopsy of the lining of the small intestine via gastroscopy for confirmation. Responds to a gluten-free diet.

Weakness of the cervix of the uterus revealed during pregnancy, usually because of previous operations on it, but sometimes without prior injury, leading to miscarriage, typically in the second three months of the pregnancy. Diagnosed by examining the cervix during the pregnancy, repeatedly if necessary. Often causes no symptoms until the waters break (the pregnancy membranes from the gestational sac bulge through the opening cervix), when it's usually too late to treat. Treated before rupture of the membranes with a cervical ligature.

A stitch or suture placed circumferentially around the cervix to strengthen and support it for the treatment of cervical incompetence.

Sticky secretion from the canal of the cervix, the job description of which is to keep sperm (spermatozoa) out unless ovulation is about to take place, when it becomes voluminous, watery, stretchable (Spinnbarkheit) and forms a crystalline ferning pattern when allowed to dry on a glass slide. Natural family planning clinics can teach you to look for it in the vagina -- useful for getting pregnant as well as for avoiding it.

Estimation of sperm antibodies in the cervical mucus. The presence of these antibodies can cause negative tests of cervical mucus-sperm interaction, including a negative postcoital test.

A polyp of the canal of the cervix. A cause of bleeding after sex (postcoital bleeding). Sometimes accompanied by an endometrial polyp, which can cause infertility, and which should thus be looked for with a transvaginal ultrasound.

An ectopic pregnancy located in the wall of the cervix. A particularly dangerous condition because of the risk of uncontrollable bleeding.

A score (out of 12) for the quality of cervical mucus, gauged by scoring each of the following from 0 to 3: the cervix should be open and the volume of mucus should be good (although every woman will be different for both these parameters, they will be consistent in one woman from ovulation to ovulation); the mucus should be clear, watery and stretchy (Spinnbarkheit); and the mucus should produce a complete 'ferning' pattern when it's allowed to dry on a microscope slide. The first two criteria vary at ovulation in different women (so anything above a score of 9 or 10 can be normal), but the same woman should achieve the same Insler score from one ovulation to the next. Also called the Insler score.

Inflammation of the cervix, usually because of infection. Sperm might or might not have trouble getting through the cervical mucus: this can be tested with a postcoital test. Occasionally cervicitis can mean that there is endometritis and salpingitis, in which case there will usually be pus present in the cervix. A cause of intermenstrual bleeding and postcoital bleeding. Clinically there might be contact bleeding when taking a PAP smear.

The "neck" of the uterus, lying between the body of the uterus (its fundus) and the vagina. See also, cervical mucus, cervical polyp, cervical pregnancy and cervicitis. The embryological development of the cervix and congenital abnormalities.

A GnRH-antagonist made by Serono. Approved for women undergoing in vitro fertilisation), with good results when started on day 7 of the cycle, after 5 or 6 days' Gonal-F in suppressing the LH surge; the dosage, however, appears to be critical, to avoid over-suppressing natural luteinising hormone. Marketed as Cetrotide.

The condition when an individual shows two or more genetically different cell lines that are derived from different zygotes, because of intermingling (see microchimerism). Chimerism on a micro scale is more common than generally appreciated, in the sense that most mothers who have had a child will, on careful investigation, be shown to have some white blood cells derived from their fetus or fetuses. See also mosaicism and mixoploidy, although most cases of chimerism do not cause an abnormality of the karyotype.

A germ, or infective agent, responsible for infection of, and damage to, the fallopian tubes. In men particularly, chlamydial infection can cause nonspecific urethritis, with a feeling of burning during the passing of urine or with a yellow-colored discharge from the penis. In women, there can be a vaginal discharge or there can be mild or moderate abdominal pain from acute salpingitis; it should be suspected whenever there is yellow-colored mucus in the cervix during the taking of a Pap smear (i.e. when there is cervicitis). There might be no symptoms in either sex. The diagnosis of a current, untreated infection is made by testing cell scrapings from the canal of the cervix or from the urethra. As a germ, chlamydia is like a virus in some ways (it can grow only inside cells) and like a bacterium in others (it responds to some antibiotics -- especially tetracyclines and erythromycin). When it's diagnosed, both partners should be treated. A past infection can be revealed by measuring serum chlamydial antibodies, although false positive tests can occur.

A cyst of the ovary caused by endometriosis. The name comes from the old, dehydrated and thickened blood that it contains. Often causes an increase in serum CA 125 antigen and can usually be seen on transvaginal ultrasound.

hCG made by Ferring.

Generic name for recombinant human chorionic gonadotropin.

The outermost of the two membranes surrounding the gestational sac that encloses the developing embryo. Separate from the amnion until about 14 weeks of pregnancy, after which the two membranes stick together without intervening fluid. Like the placenta, with which at the margins it is joined seamlessly, derived from trophectoderm.

A gonadotropin produced by the trophoblast of the placenta that acts like luteinising hormone.

A tongue of tissue within the placenta composed of chorion and containing capillaries connected to the blood circulation in the fetus that laps the mother's blood in the uterus, exchanging oxygen, nutrients and waste products between the fetus's blood vessels (in the villi) and the mother's blood. This tissue is sampled for genetic testing with a CVS (or chorionic villus sampling. See also intervillous space. Plural: chorionic villus.

(CVS) A test done at about 9 weeks pregnancy at which, under the guidance of transvaginal ultrasound, a catheter is passed through the cervix of the pregnant uterus to obtain a small sample of tissue from the placenta (the afterbirth) for genetic testing, such as a karyotype.

The name given to the products of a chromosome that has divided during meiosis or mitosis, before separating off as separate daughter chromosomes.

Remember that the ordinary cells of the body have 46 chromosomes in 23 pairs. The members of each of the pair don't contain the same genes (this is why you can carry a gene for recessive inheritance without being sick, but if you have both genes there's trouble). During the cell divisions that produce the germ cells (the process of meiosis), the 46 chromosomes first double to 92 before they end up with the 23 present in an egg or a sperm. Two of the four sibling chromosomes (we call them chromatids) then randomly exchange bits of themselves: there's a "cross-over". The points of junction where this happens are called chiasmata. Nature is jumbling up where the genes will end up so that in the long run you don't always have to inherit two particular genes together just because they live next door to each other on a chromosome. Cross-over does not mean that genes can end up in any chromosome they like: unless "translocated", they will remain in pairs (of alleles) within a particular pair of chromosomes. Chromosomal crossover is the origin of what geneticists call hybrid vigor.

When the embryo or fetus is abnormal because of a mistake in its number of chromosomes (see aneuploid and polyploid), with too much or too little genetic material. Usually causes miscarriage. Revealed by performing a karyotype on the products of conception.

Failure of chromatids to separate after chromosomal cross-over during meiosis. The origin of aneuploidy. More common in eggs, or oocytes, than sperm, and increases with age in women.

The mixture of a single (but double stranded) long string of genetic material (DNA) wound around supporting proteins. There are 46 chromosomes (23 pairs) in every normal human cell (other than the germ cells). Each cell therefore contains all the genetic information needed to make a human being. But it's only in the first few days of the embryo that all of a cell's DNA is accessible: once cells differentiate to have special purposes only the DNA they need remains unmasked. Chromosomes are located in the cell's nucleus and come in pairs, so that each cell has two alleles of each gene.

Medically, means slow to develop, and lingering or long-lasting. A chronic inflammation typically consists of fibrous (scar-like) tissue. Opposite to acute.

Tiny hair-like projections on the surface of some cells, which are thus called 'ciliated'. Coordinated beating of the cilia moves mucus and mucus-like substances (such as the cumulus mass) on the surface of ciliated cells in the direction of the cilial beat. An individual cilium has the same basic sub-microscopic structure as the tail (the flagellum) of a sperm cell (a spermatozoon). See also immotile cilia syndrome. Plural: cilia.

Process by which a fertilised egg divides repeatedly over several days, forming (for a time) smaller and smaller cells; the process begins at the stage of the zygote and ends with a morula.

Brand of clomiphene made by Marion Merrell.

A drug that blocks the action of estrogens and so tricks the pituitary gland into thinking the ovary's follicles are not producing enough estradiol, so that natural FSH production is temporarily increased, the ovaries thereby are stimulated, and follicles grow. The LH surge and ovulation usually follow naturally, but human chorionic gonadotropin can be given if monitoring is used to make sure the follicle is properly mature. Brand names: Clomid (Marion Merrell) and Serophene (Serono)

Originally a botanical term meaning asexual reproduction, or reproduction by "budding" rather than by genetic recombination involving an egg and a sperm. Animals can be cloned either by splitting an embryo during cleavage (nature does this in producing monozygotic twinning) or by inserting an adult cell nucleus into a suitably primed secondary oocyte, a process called somatic cell nuclear transfer (and generally still very inefficient, resulting in a new developing embryo in at most a few percent of attempts). See also therapeutic cloning and reproductive cloning.

A complex set of blood and tissue components capable of a cascade of events causing blood to clot. The central event is the conversion of soluble fibrinogen to insoluble, polymerised fibrin through the action of thrombin. In a more moderate way, the coagulation system (and these molecules) lay down the scaffolding for normal development of the placenta, so that abnormalities of blood coagulation may contribute to recurrent miscarriages.

Latin for having sex

An operation to remove the colon, performed in children for Hirschsprung's disease and in young women chiefly for ulcerative colitis and Crohn's disease, and notorious for leaving the fallopian tubes caught up in "repaired" serosa of the pelvic peritoneal cavity, producing a hydrosalpinx on the left side, with resultant sterility, even though the tube on the right side might be normal.

Achieving pregnancy with the help of a third party to provide any of: the spermatozoa (see donor insemination); the oocytes (egg donation); or the uterus (surrogacy: see gestational surrogacy and traditional surrogacy). Current issues surround the question of whether or not to inform the child of his or her origins, whether the donor or surrogate should be anonymous or take some part in the child's upbringing, exploitation and autonomy, and (in the case of sperm donation) access to sperm banks by women not in a heterosexual relationship with a sterile man.

Process by which the separate cells of the early embryo fuse together to form, for the first time, a tissue. Typically occurs at the stage called the morula. With compaction, it becomes difficult to detach a cell for preimplantation genetic diagnosis.

(CGH) A molecular DNA diagnostic technique whereby a set of chromosomes (a genome) is compared with a standard set using different colored dyes (typically red and green), so that any areas that do not exactly match will appear green or red instead of brown; a sensitive technique that can be applied to preimplantation genetic diagnosis as well as to chorionic villous sampling, or CVS, and to amniocentesis for prenatal diagnosis, yielding results much faster than is possible with a formal karyotype and more comprehensively than is possible with fluorescent in situ hybridisation.

A rapidly self-amplifying system of molecules in the body capable, when triggered by the immune system, of killing faulty or foreign cells or bacteria by puncturing their membranes and dissolving their contents.

Traditionally, any miscarriage revealed to be complete upon careful inspection of the expelled pregnancy tissue (the "products of conception", meaning that a uterine curettage was not necessary to avoid the risk of retained tissue causing more bleeding or infection. Nowadays we can distinguish a complete from an incomplete miscarriage (and whether or not a curettage should be done) with a transvaginal ultrasound, which can reveal significant retained tissue.

A heterozygous state in which the inherited alleles of the particular gene are different and both harmful, with clinical effects similar to a homozygous state.

The act of becoming pregnant. Traditionally, the fertilisation of the egg (the oocyte) by a sperm (the spermatozoon) and the beginning of the growth of the embryo [Butterworths Medical Dictionary]. Since the advent of in vitro fertilisation, conception is said to have occurred only if the conceptus has undergone successful implantation, as evidenced by a positive pregnancy test. See also conception rate and pregnancy.

The percentage of months or treatment cycles that result in conception, including biochemical pregnancies, ectopic pregnancies, miscarriages and all potentially viable pregnancies (twins are not counted twice); less important for most purposes than the implantation rate, pregnancy rate, viable pregnancy rate and the take-home-baby rate.

The product of conception from fertilisation.

An adjective meaning that something, especially an abnormality or anomaly, is present from birth. The cause for such a condition can be hereditary (genetic) or it can be an environmental factor operating before birth.

Abnormal development of a body part during the life of the embryo or fetus, usually but not always apparent at or soon after birth. It can be genetically inherited or be acquired by exposure to a physical or chemical insult, such as the action of a teratogen (a drug or other substance in the environment), during development in the mother's uterus. Few congenital abnormalities can be associated with a specific cause, and an apparent cause might not be the true one.

Congenital (present from birth) absence of the two vasa deferentia, which conduct sperm from the testes to the ejaculate; hence a cause of obstructive azoospermia. Because the vas deferens is usually affected on both sides, the word "bilateral" is often inserted, as CBAVD. Infertility is inevitable, but can be overcome using in vitro fertilisation with testicular sperm extraction. The cause, however, is usually the presence among the man's genes of one of the serious alleles for the genetic disease cystic fibrosis (which, having recessive inheritance, results when there are two such alleles present); it can also come about when there are one or two of the less serious abnormal alleles for this condition. The more common of the abnormal alleles should therefore be screened for (using a specially set up polymerase chain reaction on white blood cells): should an abnormal allele be present (delta F508 is the most common seriously abnormal one), the woman should be screened too, to predict the chance of cystic fibrosis occurring in the offspring.

(CAH) Enlargement and abnormal function of the adrenal glands, usually from before birth, owing to a genetically determined, partial block in the production of cortisol, the adrenal glands' main hormone, resulting in overproduction of subsidiary hormones, including androgens, tending to virilise the female fetus, which can present at birth with intersex. In mild forms does not manifest until puberty, when the symptoms of oligomenorrhea and hirsutism mimic those of polycystic ovary syndrome. See also serum 17-hydroxyprogesterone.

When a research study is done (an "experiment", maybe), the procedure, drug or process being tested or examined on the treatment group needs to be compared with a similar group that doesn't receive the treatment; we call this group the control group. The groups can consist of people, embryos, research animals, for example.

A commonly used term for an interstitial pregnancy, but can also refer to an angular pregnancy, a pregnancy in a unicornuate uterus or a pregnancy in one side of a bicornuate uterus.

Latin for yellow body, the description being that of the solid or cystic structure in the ovary after ovulation. Derived from the ovulating Graafian follicle. At first red and friable as arteries and veins invade the collapsed follicle, it soon matures into a gland that is very efficient at producing progesterone, a hormone that's soluble in the fat and which therefore gives the corpus luteum its yellow color. Provides its name to the second, or luteal phase of the ovarian cycle, as well as to luteinising hormone, which causes the corpus luteum to be formed and sustains it until, in the event of pregnancy, it is supported instead by human chorionic gonadotropin. The appearance of the corpus luteum on transvaginal ultrasound is so variable (and so able to be confused with a serious abnormality of the ovary) that for accurate diagnosis of such pathology it is best to scan in the follicular phase or while taking a progestogen to prevent formation of this structure. Plural: corpora lutea.

A vaginal gel that contains 8%progesterone. Well absorbed and with a potent local effect on the endometrium. Used to mimic (or supplement) the ovarian luteal phase. A weaker (4%) formulation is available for longterm use in patients with polycystic ovary syndrome or after the menopause to prevent endometrial hyperplasia.

Storage (at the very low temperature of liquid nitrogen) of sperm, embryos or (very recently, but still controversially) unfertilised eggs, after special preparation of these cells during cooling to replace much of the water they contain with a cryoprotective substance such as dimethylsulfoxide, propanediol or glycerol. Storage is biologically safe for a decade or more, but the existence of banks (especially of embryos) has been a concern of some in society.

Literally, "hidden menstruation". Apparent amenorrhea caused by an obstruction to the outflow of periodic bleeding from the uterus. Causes include an obstruction in the vagina. Typically there is periodic pain coinciding with the timing of the hidden menstrual flow. The causes of cryptomenorrhea include an imperforate hymen.

Literally (from the Greek), "hidden testicle". A condition in which there is incomplete descent of the testis or testes from the abdomen into the scrotum. Synonymous with undescended testis.

The fluid in which cells or tissues, including eggs, sperm and embryos, are grown. It consists of water, salts and nutrients. Different media have turned out best for different purposes. In the early days of in vitro fertilisation, several different media seemed to produce equal results: examples included Ham's F10, Whittingham's T6. Quinn's medium (said to be based on human tubal fluid, though in reality different to the fluid in the fallopian tube) produced better results than the first generation media. Today's third generation media, or stage specific media, give superior results and are used increasingly. Plural: culture media.

The accumulating chance, month after month, of successfully having gotten pregnant. With a monthly fertility (a monthly chance of pregnancy, or fecundability) of, say, 20 percent, there's a 20% chance of pregnancy by the end of the first month, a 20% of 80% (= 16%) chance of pregnancy in the second month, and so a cumulative 36% (20%+16%) chance by the end of the second month.

A collection of specialised granulosa cells, surrounding the ovulating egg (or secondary oocyte) in a sticky, mucus-like matrix. Sticks to the fallopian tube's fimbrial end after ovulation by a specific interaction with the tube's cilia.

The operation of scraping out the contents of a hollow cavity (such as the endometrial cavity of the uterus) with a curette, for making a diagnosis or for therapeutically removing abnormal tissue. A D and C is abbreviated jargon for dilatation of the cervix and curettage of the uterus). When a curettage is done to empty the uterus of normal or abnormal pregnancy tissue, a special suction apparatus is used and we refer to the operation as a vacuum curettage.

Spoon-shaped instrument for carrying out curettage.

A progestogen that is particularly effective at blocking the effect of male sex hormones (androgens)on the skin, and therefore reducing abnormal hair growth (hirsutism) and acne. Found singly in Androcur and in combination with an estrogen in Diane-35, a formulation used for oral contraception. Dangerous if taken in pregnancy, because it stops male fetuses from developing normal genital organs. Not available in the US.

A serious genetic disease (with a recessive inheritance pattern) characterised by a major disturbance of the body's mucus secretions, and thus a cause of incapacitating disease of the lungs. Important in our context because the heterozygous (or carrier) state in men can manifest with azoospermia due to congenital absence of the vasa deferentia -- the infertility of which is nowadays able to be overcome with testicular sperm extraction and ICSI, thus risking inadvertent transmission.

Soluble signalling molecules produced by cells to activate the immune system.

The part of a cell that is not the nucleus (the nucleus contains the chromosomes). The cytoplasm is contained by the cell's plasma membrane and contains all the other cellular structures, including the mitochondria. Genetic inheritance is mostly by way of the nucleus (with a contribution from mother and father); a small part is by way of the cytoplasm (with a contribution only from the mother). It is the cytoplasm of the egg (as a secondary oocyte) into which a sperm cell (spermatozoon) is injected in the process of intracytoplasmic sperm insertion. See also mtDNA.

Cells in the developing placenta that are derived from the early embryo's outer layer (the trophectoderm of the blastocyst) and then persist through pregnancy, producing either syncytiotrophoblast or extravillous trophoblast.