The state of being with child [British Medical Dictionary]; specifically, the condition from implantation of the conceptus until its delivery.

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.

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 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.

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

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.

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 pregnancy implanted in an abnormal location, such as the fallopian tube (see tubal pregnancy), the cervix (see cervical pregnancy), the ovary (see ovarian pregnancy) or the peritoneal cavity (see abdominal pregnancy).

The percentage of ectopic pregnancies among total clinical pregnancies (excluding "biochemical pregnancy"). Until a generation ago, the rate was about 0.3 percent, and this can be regarded as the incidence in normal women. The rate is increased with abnormalities of the fallopian tubes, assisted conception, and other circumstances, so that nowadays ectopic pregnancies account for about 2 percent of pregnancies in western societies.

The coexistence of a pregnancy in the uterus with an ectopic pregnancy.

An order of multiple pregnancy higher than twins.

An ectopic pregnancy located in the interstitial segment of the fallopian tube. An especially dangerous form of tubal pregnancy, because the surrounding myometrium of the uterus supports the pregnancy's growth for weeks without causing symptoms; when rupture eventually occurs it can be catastrophic, because a main branch of the main artery to the uterus is torn, with sudden (sometimes fatal) bleeding into the peritoneal cavity.

An ectopic pregnancy located in the substance of the ovary, presumably because an egg (an oocyte has been fertilised while still in a follicle).

The percentage of months or treatment cycles that result in clinical pregnancy, excluding biochemical pregnancy, but including ectopic pregnancy, miscarriage and all potentially viable pregnancies (twins are not counted twice; stillbirths and all live births are included). Less important for most patients' purposes than the take-home-baby rate. Less useful for embryologists intent on quality control in the laboratory than the implantation rate.

Nowadays a measurement of human chorionic gonadotropin in serum or urine, usually as a simple 'yes' or 'no' test. In principle a single test cannot distinguish a normal pregnancy from an ectopic pregnancy or one destined to miscarry (a miscarriage).

An estimate of likely fertility in secondary infertility, where the time it took to get pregnant the first time is used as a very approximate guide to what might be expected next time round. Of limited usefulness, but if it took a long time to get pregnant the first time it will typically take at least as long next time. Achieving a pregnancy does not usually itself permanently cure subfertility.

An ectopic pregnancy located in the fallopian tube; most occur in the ampulla, but others can be located in the narrower isthmus or in the interstitial segment.

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

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%).

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.

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.

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.

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.

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.

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.

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.

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.

(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.

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.

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.

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.

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.

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.

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.

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.

Differentiated endometrium of pregnancy which is shed (like a deciduous tree sheds its leaves) at childbirth or miscarriage, as part of the afterbirth. During pregnancy it has important hormonal functions (see decidual cells).

Plump endometrial stromal cells, lying between the glands of the endometrium, formed under the prolonged influence of progesterone, especially with establishment of pregnancy. Constitutes the decidual reaction to form the decidua of pregnancy, and produce prolactin (important for regulating water entering the gestational sac) and relaxin, which keeps the myometrium quiet.

A transformation of the lining of the uterus (the endometrium) in pregnancy. Complete confluence of endometrial stromal cells (lying between the endometrial glands) occurs, caused by prolonged (14 days or more) exposure to progesterone or a progestogen; normally happens only with pregnancy.

Due to trisomy 21. Chromosome 21 is the smallest of the "autosomes" (the non-sex chromosomes): trisomies of the other autosomes tend to be lethal at an earlier stage of embryonic or fetal development, and so are seen much more rarely. Diagnosis of Down's syndrome requires a karyotype, obtainable from pregnancy tissue by chorionic villus sampling (CVS) or amniocentesis. Screening for increased risk in pregnancy can be performed by triple screen or by looking for nuchal translucency at transvaginal ultrasound.

One of the two most important variables (the other is time left for conception) that determines the chance of still getting pregnant naturally in subfertility, including unexplained infertility. The longer the duration of infertility, the smaller the chance each month as time goes on. See also fecundability and time to pregnancy.

A polyp of the endometrium (lining of the uterus), sometimes without symptoms, sometimes with abnormal bleeding such as intermenstrual bleeding, premenstrual spotting or heavy periods. A cause of infertility (and of failure of assisted conception to result in pregnancy). Diagnosable with transvaginal ultrasound.

Loose connecting-type ('connective') tissue that lies between glands of the endometrium. Contains stromal cells that eventually respond to progesterone by becoming plump to form a more or less continuous sheet towards the end of the menstrual cycle (the predecidual reaction) or, more completely, with successful implantation and pregnancy (the decidual reaction).

Elective single embryo transfer. Choosing to have just one embryo transferred after in vitro fertilisation even though there is more than one embryo that is suitable; the other suitable embryos are frozen and stored. A strategy to increase the chance of taking home a baby by minimising the risk of multiple pregnancy, which carries a higher risk of miscarriage and stillbirths.

A weak estrogen. Increased in pregnancy, especially late pregnancy.

Technical speak for the monthly chance of pregnancy, or monthly fertility rate, either for an individual (measured over time) or for a population (the number of conceptions occurring in one month). For any individual with unexplained infertility and in milder cases of subfertility, chiefly determined by the duration of infertility (or, in cases of secondary infertility, in which past fecundability is being estimated, determined by time to pregnancy). Once calculated this way, an estimate of the chance of still getting pregnant naturally (as opposed to undergoing assisted conception) will chiefly be determined by the time left for conception.

A controversial and emotionally hazardous way of dealing with a higher-order multiple pregnancy (such as quadruplets, quintuplets, or higher) in which, all the embryos or fetuses are at risk of being lost before viability. The technique involves carrying out transvaginal ultrasound and injecting a lethal substance (such as air or a solution of potassium) into the visibly beating heart of one or more of the embryos, so reducing the number of surviving embryos to three, two or one. Generally regarded as a more stressful procedure than even an induced abortion, both for the person undergoing the operation and for the ultrasound doctor asked to do it. Few people regard the availability of fetal reduction to mean that the greatest care does not need to be taken to avoid higher-order multiple pregnancies in assisted conception programs. There's a hazard: loss of the remaining fetuses from miscarriage; but the risk of this, with an experienced ultrasound doctor or fetal medicine specialist, is low.

An operation for sterilisation or "tubal ligation" in which the fimbrial end of each fallopian tube is removed. It has a higher failure rate than most other sterilisation operations on the tubes and it also is more difficult to reverse if the woman intends to regain fertility. It can result in a hydrosalpinx, which can jeopardise success with in vitro fertilisation, and the microsurgery operation to reverse it, salpingostomy, is much less often followed by pregnancy than tubal anastomosis operations are.

An assisted conception procedure in which unfertilised eggs plus sperm (i.e. gametes) are transferred to the fallopian tube, so that fertilisation occurs in the normal place. Because in vitro fertilisation is avoided, for some people GIFT is more morally acceptable than IVF is. The disadvantages are that laparoscopy is required and that for the pregnancy rate to be comparable to IVF too many eggs need to be transferred, risking high multiple pregnancy.

A fluid-filled bag of membranes in which the embryo forms during pregnancy. Visible on transvaginal ultrasound from about 5 weeks from the last menstrual period. Technically, the amniotic cavity (and later in pregnancy able to be sampled with amniocentesis).

A form of collaborative reproduction in which the woman who is the surrogate for the intended pregnancy receives embryos from the commissioning infertile couple, who have undergone in vitro fertilisation, then, by becoming pregnant, carries (or 'gestates') the pregnancy, gives birth, and then gives up the baby to the baby's genetic parents. In principle the practice can be done for altruistic or commercial reasons.

Any hormone that switches on the function of the gonads. There are two main families of gonadotropins: (a) the gonadotropin that stimulates the growth of the follicle, or follicle stimulating hormone (FSH); and (b) those that cause ovulation from the mature follicle and stimulate the corpus luteum that results to develop and to produce progesterone, namely luteinising hormone (LH) and human chorionic gonadotropin (hCG). FSH will cause growing follicles to produce the estrogen estradiol, provided that a small amount of LH (or hCG) is present. FSH and LH are produced in the pituitary gland, whereas hCG comes from the placenta in pregnancy. In men, FSH stimulates the Sertoli cells of the testicular tubules, and hence drives spermatogenesis; LH and hCG stimulate the Leydig cells to produce testosterone.

A naturally occurring 'anticoagulant', or substance that stops blood from clotting. Used in medicine generally to prevent or to treat thrombosis, and sometimes in pregnancy to reduce the risk of miscarriage in someone who has had recurrent miscarriages by improving blood flow in the placenta. Administered by injection under the skin.

Human leukocyte antigens, also known as tissue typing molecules, responsible for acceptance or rejection of tissue grafts, and implicated in the survival or rejection of the fetus in pregnancy.

(hCG) A gonadotropin produced by the placenta in pregnancy (specifically it's produced by the trophoblast of the chorionic villi); the hormone measured in performing a pregnancy test. The generic (no frills') name for Pregnyl and Profasi, which are preparations of hCG obtained by extracting it from the urine of pregnant women, and Ovidrel, which is made by recombinant gene technology. Mimics the action of luteinising hormone (LH), but has a very much longer duration of action -- and this gives hCG considerable advantages over LH in clinical use. Given as an injection to lead to ovulation from a mature follicle 38 hours after the injection; or to stimulate ongoing function of the corpus luteum, particularly its production of progesterone. So it is typically given after a course of follicle stimulating hormone (FSH) in assisted conception (IVF or GIFT) programs and ovulation induction programs 36 hours before the expected time of egg retrieval (or before having sex or IUI), and then sometimes in further, smaller doses to support the luteal phase that follows. Sometimes used with clomiphene. Ovarian monitoring is needed for its correct use with FSH or with clomiphene. hCG treatment can precipitate the ovarian hyperstimulation syndrome (OHSS).

A hydatidiform mole in which there is no embryo or fetus. The size of the uterus is often larger than expected from the date of the last menstrual period, often with a high level of serum hCG; there may be bleeding; and there is a classic abnormal appearance on transvaginal ultrasound. Caused by pregnancy following abnormal fertilisation in which the oocyte is 'empty', that is it loses its pronucleus, and either (1) the male pronucleus from a single fertilising sperm doubles (the karyotype of the mole is then always 46,XX, because 46,YY is immediately lethal) or (2) there are two male pronuclei from two fertilising sperm (in which case the karyotype is either 46,XX or 46,XY). Treatment is by vacuum curettage, but there is a persisting danger of cancer (choriocarcinoma) and specialist medical follow-up is essential.

Abnormal conceptus in which there is coexistence of a hydatidiform mole with a fetus; caused by triploidy. Not as dangerous as a molar pregnancy without a fetus (see hydatidiform mole, complete), but medical follow-up is still necessary.

Blockage of the outer, or fimbrial end of the fallopian tube, usually as a result of chronic salpingitis (but also sometimes from peritubal adhesions, from a salpingotomy or partial salpingectomy for a tubal pregnancy, or from fimbriectomy), resulting in its distension by watery contents. An untreated hydrosalpinx (even if only one tube is affected and the other tube is normal) can cause infertility and failure to conceive even with in vitro fertilisation.

The process by which the embryo's trophoblast attaches to the mother's endometrium and penetrates it, establishing contact between the trophoblast's developing chorionic villi and the maternal blood. See also blastocyst. Signifies the commencement of gestation or pregnancy.

A small to moderate amount of vaginal bleeding at the time that implantation becomes established. Implantation bleeding can be confused with a menstrual period (particularly the last menstrual period) to give a false impression that pregnancy has not happened or, later, a false estimate of the duration of the pregnancy.

The proportion of transferred embryos in an in vitro fertilisation procedure that produce a gestational sac visible on transvaginal ultrasound. Unlike for the conception rate and the pregnancy rate, twins (with separate sacs) are counted separately. An important index of a clinic's success rate with IVF because it reflects embryo quality independently of the number of embryos transferred.

(IMC) Any miscarriage before all miscarriage tissue has been expelled. Traditionally a uterine curettage was done after a miscarriage, in the belief (often accurate) that there would still be some immature pregnancy tissue left in the uterus that could cause more bleeding and get infected. Nowadays we can distinguish an incomplete from a complete miscarriage (and whether or not a curettage should be done) with a transvaginal ultrasound, which is able to reveal significant retained tissue. Management is similar to the management of an inevitable miscarriage (and both are abbreviated IMC).

(IMC) Traditionally any bleeding from the vagina during early pregnancy with, on vaginal examination, opening of the cervix. Today, the diagnosis can be made much sooner (and distinguished from a threatened miscarriage) by not detecting a normal embryo in a gestational sac on transvaginal ultrasound. Management is similar to the management of an incomplete miscarriage, often requiring curettage (and both are abbreviated IMC).

A signalling molecule that inhibits the immune system, so preventing rejection of the fetus during pregnancy. It is thought that insufficient interleukin 10 is a cause of miscarriage.

A reproductive strategy where survival of a species is optimised by placing a premium on individual survival despite fluctuations of the environment. Favors large animals (and large animals favor this strategy) -- animals that get pregnant more than once and the offspring of which require postnatal care before sexual maturity is reached. Spacing of pregnancy is important for survival of mother and offspring, and thus favors the evolution of a genetic basis for subfertility. The opposite reproductive strategy to r-selection. The word comes from the environment's Karrying capacity.

(LMP) The normal period immediately preceding conception. For convenience, obstetricians calculate the duration of a pregnancy as starting with this date, even though of course it does not truly begin until fertilisation (or, some would say, implantation).

(LPD) A luteal phase that is shorter than optimal for a fertilised egg to undergo implantation. Very likely if the luteal phase is shorter than normal (11 to 16 days), but not all luteal phases within this range are innocent. Often caused by a prior defect of the follicular phase or of the development of the ovulating tertiary follicle (the preovulatory follicle) and hence there can be a defect of the egg itself (if ovulation has actually occurred) or there can be a luteinised unruptured follicle -- any of which will either increase the risk of miscarriage or will prevent pregnancy altogether for that cycle. Synonymous with luteal phase insufficiency.

For our purpose in the book, the loss of an early embryo at or before the expected time of a period. Not noticeable without specially measuring levels of serum human chorionic gonadotropin One form of so-called biochemical pregnancy.

A cytotoxic drug, originally developed for chemotherapy for certain cancers, used in the treatment of ectopic pregnancy, especially in the US; side effects can include bone marrow depression, gastrointestinal upset and mouth ulcers, and other effects.

The percentage chance that a pregnancy will end as a miscarriage. The normal rate of clinically apparent miscarriage for young women is about 12 percent. The rate rises independently with age, the number of previous pregnancies, and especially the number of previous miscarriages experienced. The rate is also higher with many causes of infertility when conception occurs with or without treatment.

A miscarriage that should have happened but hasn't. As a result, the pregnancy tissue in the uterus gets tougher and more difficult to get out with a uterine curettage -- which is the only treatment for it, but risks producing intrauterine adhesions. The pregnancy test can stay positive for many weeks or even months.

Repeated loss of pregnancies at different stages of development of the embryo or fetus, i.e. at different stages of pregnancy. Related to recurrent miscarriages.

In medicine generally it may be best for tests to be negative (like tests for brain tumors or tests for sexually transmitted diseases such as HIV -- as for 'histories', compare negative history), but this is not always so in infertility. Infertility tests are generally better if they're positive, like the postcoital test, tests for ovulation, tests for tubal patency, and (not least) a pregnancy test.

White blood cells or lymphocytes that form part of the 'innate' immune system capable of recognising foreign cells and dissolving them (hence their name: natural killer cells). Found normally, however, in the endometrium of the late secretory phase and in the decidua of pregnancy, where they have more friendly purposes in forming the boundary between mother and fetus. Unlike T cells and B cells, most NK cells do not have 'immunological memory', whereby previous contact with a particular antigen causes a faster, more deadly immune response second time round.

'Pregnancy-associated plasma protein A': a protein made by the syncytiotrophoblast of the placenta to increase its sensitivity to grow. Found in increasing levels in the pregnant woman's serum as pregnancy develops. Decreased if the pregnancy is affected by Down syndrome, therefore measured in the triple test used for fetal trisomy 21 screening.

In medicine, it might generally be best for tests to be negative (like tests for brain tumors or tests for sexually transmitted diseases, such as HIV -- as for medical histories, compare positive history) -- but not so in infertility. Infertility tests, such as the postcoital test, tests for ovulation, tests for tubal patency, and (not least) a pregnancy test, are generally better if they're positive.

Using a contraceptive after sex instead of before it, to interrupt implantation of an embryo (if there is one). Taking two birth control (oral contraceptive) pills the morning and the night after the unanticipated opportunity for pregnancy is reasonably effective, but see your physician for details to carry this out safely and effectively. This maneuver might not protect against an ectopic pregnancy.

A syndrome occurring in late pregnancy marked by an increase in blood pressure, swelling of the ankles by fluid, and the appearance of albumin in the urine, associated with reduced blood flow to the placenta, therefore putting the fetus at risk of death, or stillbirth, and putting the mother at risk of complications from high blood pressure, convulsions (eclampsia), kidney failure, liver failure and death. Treated with drugs to lower the blood pressure and to prevent convulsions, while expediting the delivery of the baby.

A small sample (or biopsy) is taken of the lining of the uterus (the endometrium) just before a period is expected, aiming to show advanced stages of progesterone's effect on it, in the form of an adequate predecidual reaction. This a very sensitive test of the adequacy of the luteal phase. The biopsy can be combined with a laparoscopy or carried out in isolation as an office procedure. It's best to be sure that there is no possibility of pregnancy during the cycle the test is conducted, as occasionally the biopsy jeopardises an early pregnancy (namely an early implantation, before the pregnancy test or serum hCG has become positive).

In medicine the word primary can denote primacy in one of 3 ways: (1) event-wise (e.g. primary amenorrhea is when there has been no precedent -- no prior period -- whereas secondary amenorrhea) follows prior periods, and likewise the distinction between primary infertility and secondary infertility, a distinction based on prior successful pregnancy); (2) developmentally or time-wise (e.g. a primary follicle gives rise to a secondary follicle, then to a tertiary follicle); or (3) causally (e.g. primary ovarian failure is based within the ovary itself, whereas secondary ovarian failure is secondary to failure of gonadotropins). These sort of distinctions is one reason why medical school takes a long time.

Trouble getting pregnant (infertility) in someone who has never had a successful pregnancy. Although the exact definition can vary among gynecologists, the differentiation between primary infertility and secondary infertility is most useful if a prior ectopic pregnancy or a prior miscarriage is consistent with the state of primary infertility, whereas a prior induced abortion (which, the odds are, would otherwise have developed normally) means the state is secondary infertility.

The ovary's second main hormone, produced only after ovulation and during pregnancy (first by the corpus luteum, then by the placenta). Sometimes administered by injection or by insertion into the vagina in the form of a pessary to supplement natural production.

(PRL) The hormones produced by the pituitary gland to stimulate the production of milk in the breasts. Produced in increasing amount during pregnancy, although milk secretion is postponed until levels of estrogen and progesterone fall after the baby is born. For more on prolactin in the animal kingdom, and its importance in being produced by decidual cells in pregnancy.

Something you can give meaning or value to by giving it a number, such as pregnancy rate. Opposite to qualitative.

(RTF) A protein produced by the trophoblast that reduces the tendency of the mother's immune system to reject the pregnancy, apparently by increasing levels of interleukin 10, and thus reducing the tendency for miscarriage.

The use of somatic cell nuclear transfer or embryo splitting to secure pregnancy and a new individual intended to be virtually genetically identical to the person who donated the cell nucleus used or genetically identical to siblings resulting from embryo splitting (which in effect is the intentional creation of identical twins, or triplets etc.). Practiced in animals, especially farm animals. Considered ethically abhorrent because of strong ethical arguments within the fields of deontological ethics (including a duty not to intentionally violate the biological principle of sexual reproduction involving genetic reassortment and individual difference), teleological ethics (including the very high risk of severe birth defects with SCNT) and utilitarian ethics (where arguments are based on considerations by and for society generally).

(ROSNI) Experimental form of testicular sperm extraction (TESE) followed by intracytoplasmic sperm insertion (ICSI) in which the nucleus of a round (very immature) spermatid is isolated for injection into the egg (or secondary oocyte). Intended to be used in treating non-obstructive azoospermia with severe maturation arrest, when more spermatozoa are not obtainable. Animal studies show higher pregnancy rates than with round spermatid injection (ROSI), but limited studies in humans still indicate very high rates of embryopathy. Not recommended clinically.

A nodular ('nodosa') thickening of the fallopian tube's isthmus ('isthmica'), probably due to previous salpingitis. Can cause localised obstruction of the tube and, if the obstruction is partial, an ectopic pregnancy can be caused. Overcomeable with microsurgery or tubal canalisation.

An operation involving a temporary opening length-wise along (usually) the ampulla of the fallopian tube, usually for the treatment of a (tubal) ectopic pregnancy. Occasionally performed for a pyosalpinx. Can be carried out efficiently at laparoscopy.

Trouble getting pregnant (infertility) in someone who has previously had a successful or potentially successful pregnancy. Although the exact definition of secondary infertility can vary among gynecologists, for me the distinction between secondary infertility and primary infertility is most useful if the term secondary infertility is restricted to when there has been a prior induced abortion (which, the odds are, would otherwise have developed normally) or a successful pregnancy; a prior ectopic pregnancy or a prior miscarriage is, in my view, still the state of primary infertility.

One of a number of tests to detect previous or untreated syphilis, an important (though nowadays rare) cause of birth defects and recurrent miscarriages. The chance of detecting unsuspected syphilis might be very low, but the penalty for missing it is very high, so it's still a routine test in early pregnancy. Tests are done on serum and include the Venereal Disease Research Laboratory (VDRL) test and the Wasserman reaction (WR) test. Often tested as part of a screen for infectious disease before assisted conception, although there is no evidence that syphilis is transmitted through eggs or sperm (it is caught from contact between the lining of the vagina and the surface of the penis).

Measurement of CA125 antigen in serum. A test done to investigate, particularly, adenomyosis and cancer of the ovary. Levels can also be increased with endometriosis (especially when there is a 'chocolate cyst' present), during normal menstruation and during normal early pregnancy.

Measurement of human chorionic gonadotropin in serum: essentially a pregnancy test, but carried out more precisely (quantitatively) than is the case with a yes or no test (which is qualitative). Often carried out serially, to determine if a pregnancy is: thriving (hCG levels double every two or three days in normal early pregnancy; languishing (levels rise more slowly, seen with an ectopic pregnancy and with an inevitable miscarriage); or resolving naturally (levels that are falling). Very high levels are seen with hydatidiform mole. Part of the triple screen used to screen for Down syndrome in early pregnancy.

A general term used by obstetricians or pediatricians to refer to a fetus or newborn baby that seems smaller than it should be for the assumed duration of the pregnancy so far. The three main causes are a genetic abnormality of the fetus; insufficient nutrition for an otherwise normal fetus; and an incorrect calculation of the dates, maybe because ovulation and conception took place later than the usual two weeks after the last menstrual period. Recent research shows that women with infertility might be at higher risk of small-for-dates babies when they do get pregnant.

Infertility that is not 'absolute', or 'complete infertility' -- that is, there is a chance of pregnancy: it is not sterility (these last 3 terms are synonyms) -- but the chance of getting pregnant each month (fecundability or monthly fertility) is reduced. More or less definite causes can include oligospermia, polycystic ovary syndrome and other causes of oligomenorrhea, endometriosis, peritubal adhesions, fibroids (especially submucous fibroids) and increased age, especially of the woman. Synonymous with relative infertility.

Intentional induction of multiple ovulations at once, using injections of follicle stimulating hormone and human chorionic gonadotropin, for assisted conception. Inevitably there is a risk of multiple pregnancy unless egg retrieval is performed.

The component of the trophoblast bathed by maternal blood in the placenta (and thus covering the chorionic villi). Derived by differentiation and fusion of cytotrophoblast cells, so the syncytiotrophoblast only ever comprises just one cell (albeit with very many cell nuclei), through which almost everything reaching or leaving the embryo or fetus must pass. By the end of normal pregnancy, its area is about 12 square meters, or over 100 square feet. Most hormones and proteins produced by the placenta, such as progesterone, hCG and PAPP-A, come from it.

The percentage of treatment months (or treatment cycles in assisted conception) that result in the woman taking home one or more babies (twins are not counted separately, though!); the statistic of most interest to patients and, in an age of skepticism in the community, the most politically correct statistic for reproductive medicine clinics to quote, but it's less useful for clinics' quality control purposes than the conception rate, the implantation rate, and the viable pregnancy rate, because: (1) it excludes obstetric misadventures often beyond the control of the infertility clinic; and (2) there is a long lag before it can be calculated, making results at best about 9 months old.

Traditionally, any bleeding from the uterus during pregnancy while the cervix is (still) closed. Today, as well, there would need to be a normal embryo and, a little later, normal fetal heart movement pattern on transvaginal ultrasound to separate it from an inevitable miscarriage.

An increase in the tendency of the blood to clot, as in 'thrombosis'. In primitive, evolutionary times, a survival advantage for women giving birth, when loss of blood would on average be less, but exacting a price in terms of increased risk of stroke or venous thrombosis. The thrombophilias are implicated in disturbances of pregnancy, including recurrent miscarriage and stillbirth.

One of the two most important variables that determine the chance of still getting pregnant naturally in subfertility and unexplained infertility (the other is duration of infertility). The longer the time still available the better the chance that, sooner or later, pregnancy will happen. Broadly limited by the female partner's age, but personal circumstances and ambitions within the biologically available timeframe might shorten it, leading to a decision to seek treatment with assisted conception.

Surrogacy in which the woman who is the surrogate for the intended pregnancy provides the eggs (through her own ovulation); is impregnated by assisted insemination; carries (or 'gestates') the pregnancy; gives birth; and then gives up the baby to the person who commissioned the surrogacy arrangement. Also known as genetic-plus-gestational surrogacy. The surrogate is as much the biological mother of the child as if she had conceived in natural circumstances, except that the male by whom she has been impregnated has no prior social relationship with her. No countries other than the US, where commercial surrogacy can be legal, have encouraged the practice, whether for altruistic or commercial reasons.

Ultrasound imaging of the pelvic organs for diagnosing abnormalities of (particularly) the uterus and the ovaries; for monitoring the development of ovarian follicles with ovulation induction and assisted conception programs; and for following the course of early pregnancy. Among the pioneers were Dr Karl Popp, who used a mechanical sector scanner vaginally in Hamburg in 1984, and Dr John Anderson, who used the first vaginal linear array scanner at Sydney IVF in 1985, leading to its widespread use subsequently in Australia and the US.

Literally, a three-month period of time; so the nine months of pregnancy are divided into the first, second and third trimesters. Most miscarriages take place in the first trimester (up to 12 or 13 weeks). Pregnancies that reach the third trimester (beyond 27 weeks) have an increasingly good chance of being viable (though nowadays, with intensive care, survival has occurred from about 24 weeks).

A screen for congenital abnormalities of the fetus done on the mother's blood serum during pregnancy to look for fetal trisomy, including Down syndrome. The original test comprised measurements of (1) serum alpha fetoprotein (decreased in the trisomies), (2) serum hCG (increased in trisomy 21, decreased in trisomy 18), and (3) serum estriol (decreased in trisomy 21, increased in trisomy 18). Note that only 60% of pregnancies with Down syndrome will be revealed by a triple test. Refinements have taken place, with 'free beta' (part of the hCG molecule) replacing hCG itself, and with the addition of PAPP-A replacing estriol, increasing the sensitivity and specificity of the test. Further gains in sensitivity and specificity comes from adding an ultrasound test for nuchal translucency. Even so, false positive tests are possible, which will be resolved only by performing CVS or amniocentesis, and so also are false negative tests, which means that CVS and amniocentesis should still be considered in otherwise high-risk situations.

A tubal ectopic pregnancy that is in the process of being expelled out the fimbrial end of the fallopian tube.

A uterine anomaly that comes about when the uterus forms (in the embryo) from just one Mullerian duct; the uterus will be a little smaller than normal (making a miscarriage or premature labor more likely), and will be connected by a fallopian tube to just one ovary, contributing slightly to infertility (since, on average, only half of ovulations have a chance of resulting in pregnancy). Reproduction, however, can be normal, and a woman might go through life with a unicornuate uterus and not know it. Diagnosed by hysteroscopy and laparoscopy, by hysterosalpingogram or -- particularly effectively -- by three-dimensional ultrasound. Often there is a simultaneous abnormality of the kidneys, such as one kidney instead of two, diagnosable by abdominal ultrasound or, more specifically, by a special kidney x-ray study called an intravenous pyelogram.

The womb, in which pregnancy is gestated from the time of implantation of the embryo until delivery or miscarriage; formed from the joining of the two Mullerian ducts (in the absence of anti-Mullerian hormone); composed of the main, upper part (the uterine fundus) and a lower neck, or cervix, which connects it to the upper part of the vagina; most of its wall is made of muscle tissue (the myometrium), but with an inner lining of glands (the endometrium) and, on the outer surface, a thin covering of uterine serosa. Best seen on transvaginal ultrasound, especially a three-dimensional ultrasound; its cavity is best displayed with a hysterosalpingogram (or, strictly, a hysterogram).

Vasectomy reversal, the operation for reversing a sterilisation operation (a vasectomy) in a man involving removal of the blocked part of each vas deferens, in the upper part of the scrotum, and joining by microsurgery one cut end or the vas to the other cut end. Generally not as successful at returning fertility as the equivalent operation in women (tubal anastomosis): the development of sperm antibodies increases with the length of time since sterilisation and limits the effective sperm count after the reversal. Many clinics now carry out cryostorage of some sperm obtained at vasectomy reversal so that if pregnancy does not happen, or azoospermia persists, in vitro fertilisation (IVF) can be carried out with ICSI without requiring a later operation (for MESA) on the man. MESA with ICSI and IVF can be used as an alternative to vasovasostomy.

A sac-like structure attached to the under-surface of the developing embryo. The first part of the embryo to become visible on transvaginal ultrasound after the gestational sac, but not by itself as reassuring as seeing a beating fetal heart that the pregnancy will most likely avoid miscarriage. Not as important for a human embryo's nutrition as it is for a fertilised egg incubated by a hen, and in mammals contains no yolk, but the yolk sac's lumen is continuous with the lumen of the embryo's developing gut, or intestine, and shares an absorptive function. Cells from the yolk sac become incorporated into the fetus in many ways, including forming the primitive germ cells.