White blood cells or lymphocytes that are part of the immune system and concerned with the production of antibodies.

Remember chromosomes occur in pairs in all cells except sperm and eggs. If part of one chromosome is found connected to a completely different chromosome it's "translocated". For that person there is no net gain or loss of genetic material, so the translocation is "balanced" and there is no problem. But when that person makes eggs or sperm, some of these will have too much or too little genetic material. The same will be true for an embryo that results. The chromosomal translocation will then be "unbalanced" and the embryo will sooner or later usually result in a miscarriage. If the two particular chromosomes have swapped parts, we call it a balanced reciprocal translocation.

An inexpensive way of detecting ovulation through the effect progesterone has on the hypothalamus, increasing the body's temperature a few tenths of a degree. Best recorded using a BBT thermometer (with a smaller scale than thermometers used to record fevers or high temperatures) first thing in the morning before rising, and preferably in the vagina for accuracy. Day 1 of the chart is the first morning when there is menstruation (a period). Commonly there's a dip in the temperature just before the sustained rise that indicates that ovulation has occurred (a "biphasic chart"). The chart typically records the days you are menstruating, when you have sex and when you're aware of mucus and ovulation pain. Best used to document: (1) the presence and length of the luteal phase, especially if clomiphene is being used for ovulation induction; and (2) the timing of symptoms such as premenstrual spotting. Not as good for predicting ovulation as LH-testing in urine.

The ethical value that comes from doing good.

A uterine anomaly in which the Mullerian ducts, before birth, do not join completely, with the consequence that there is a double uterus, in which each of the two sides is smaller than a normal uterus and receives just one fallopian tube. Diagnosed by hysterosalpingogram, by hysteroscopy and laparoscopy, or by transvaginal ultrasound (preferably three-dimensional ultrasound).

A somewhat insensitive term for when conception and implantation have occurred, producing a positive pregnancy test, but without sign of a gestational sac appearing on transvaginal ultrasound; in other words, a subclinical miscarriage or a menstrual miscarriage.

Taking a small sample of tissue for diagnosis under the microscope. Biopsies of the endometrium can be done without anesthetic, through the cervix (see premenstrual biopsy). Biopsies of the ovary or of the lining of the peritoneal cavity (e.g. to detect subtle endometriosis) are done at laparoscopy. A testicular biopsy is done to determine why there's azoospermia. Using microscopic techniques, even an early embryo can be biopsied

Stage of development of the early embryo that has undergone blastulation, in which a fluid-filled cavity forms in the formerly solid ball of cells (the morula), about 5 days after fertilisation. For the first time, a distinction can be made between a sheet of cells to one side, which will form the embryo proper, termed the inner cell mass, and the remaining, peripheral cells that constitute the trophectoderm, which -- after the blastocyst "hatches" through the zona pellucida and undergoes implantation -- will form the trophoblast. An old-fashioned term for an inevitable miscarriage, meaning that the ovum (in its classical sense for professional embryologists) has not developed normally after fertilisation, there being present just the supporting tissues and no embryo. The term is descriptive, it has no diagnostic value as to the cause of the miscarriage.

Most commonly done before an operation that could cause significant loss of blood, especially if an ectopic pregnancy is suspected, because a blood transfusion might be needed. Also done for investigation of recurrent miscarriages, when the rare but important antibody anti-TjA needs to be excluded or detected. Rh-negative women who have a Rh-positive partner who are treated for miscarriage or for ectopic pregnancy often require an injection of Rhogam or anti-D gamma globulin to avoid being sensitised (developing antibodies to) possibly Rh Positive red blood cells from the embryo or fetus.

(BMI) An estimate of the amount of fat a person has, calculated by dividing his or her weight (expressed in kilograms) by the square of the height (expressed in meters). Normally between about 20 and 25, although the upper limit is higher with age. A BMI below 20 generally causes oligomenorrhea, then amenorrhea, through anovulation.

The intestines. The small intestine (or small bowel) runs from the stomach to the wider large intestine (or large bowel), which starts with the cecum, in the region of the appendix on the right side of the lower abdomen, ascends (ascending colon), turns left (transverse colon), turns downward (descending colon), becomes the sigmoid colon (as it sweeps from side to side a bit), then the rectum, before emerging at the anus.

Bleeding (usually irregular and light, i.e. 'spotting') while on the birth control pill (the oral contraceptive pill) or while taking a progestogen. With regard to the pill, it is common (and of no sinister importance) in the first few months of pill use; but if it happens after many months' satisfactory use of the pill then it can signal: (1) interference with the efficacy of the pill (i.e. a risk of ovulation and pregnancy) by an illness with diarrhea, simultaneously taking antibiotics, or a drug interaction (taking additional medications that speed up the pill's metabolism; or (2) coexisting pathology of the cervix or the uterus. Unexplained or persistent breakthrough bleeding means you should see your physician.

A drug that mimics dopamine, which is produced by the hypothalamus to normally inhibit production of prolactin by the pituitary gland. Specific treatment for hyperprolactinemia: the tablets are given by mouth unless they cause side effects, in which case the same tablets (but not the capsules) can be used vaginally! Made by Sandoz as Parlodel.

A GnRH-agonist, made by Hoechst as Suprefact. Administered as a nasal spray.