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PAPP-A “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.

Parlodel See bromocriptine. Made by Sandoz.

parthenogenesis Can occur when an egg (as a secondary oocyte) undergoes activation (by itself, with some non-specific stimulus, or through fertilization by a sperm) and starts to divide (it undergoes cleavage), but the male chromosomes are not incorporated and the egg remains haploid; its further development will soon stop, probably well before implantation. Can be the cause of apparent (but false) late fertilization in the IVF lab.

partial mole See hydatidiform mole, partial and triploidy.

paternalism A method of medical or administrative practice in which the values of the practitioner or administrator are imposed upon the person most affected by the decisions to be made, without adequately heeding that person’s own values or power to make decisions that directly affect them. For a discussion of paternalism in the doctor-patient relationship, read the box, Autonomy and respect for persons, in WebPage 26. See also autonomy and professionalism.

PCB See postcoital bleeding.

PCO See polycystic ovaries.

PCOD Polycystic ovary disease. See polycystic ovary syndrome.

PCOS See polycystic ovary syndrome.

PCR See polymerase chain reaction and DNA testing.

PCT See postcoital test.

Percol A laboratory medium used for separating sperm. Not approved for human therapeutic use. See PureSperm.

Pergonal Mixture of human menopausal gonadotropins containing follicle stimulating hormone made by Serono; virtually equivalent to Humegon.

perimenopause A time of intermittent symptoms of the menopause that first becomes apparent as egg numbers in the ovaries fall far enough to cause shortening of the menstrual cycle, particularly the follicular phase, and accompanied by elevation of serum FSH when measured during menstruation. As it progresses, menstrual cycles can shorten considerably, while becoming interspersed unpredictably by unusually long cycles, sometimes producing cystic follicles and even anovulatory dysfunctional bleeding, as well as episodes of hot flashes. Different from the oopause.

peritoneal adhesions See adhesions.

peritoneal cavity The general abdominal cavity in which lie the stomach, the intestines, and the uterus, ovaries and fallopian tubes, each covered by a thin, moist, slippery surface layer, the peritoneal serosa (or peritoneum). An examination of the peritoneal cavity is called a laparoscopy. See also adhesions.

peritoneal serosa The serosa of the peritoneal cavity.

peritoneum The smooth, moist lining of the peritoneal cavity that forms the serosa of the organs this cavity contains. For purists, such serosa is visceral peritoneum and the part of the peritoneum covering the wall of the abdominal cavity away from organs is called the parietal peritoneum.

peritubal adhesions Adhesions around the fallopian tube.

perivitelline space The space between the egg (the vitellus -- the oocyte itself) and the zona pellucida; sperm are injected into this space with subzonal insertion, or SUZI.

PGD See preimplantation genetic diagnosis.

pituitary fossa See pituitary tumor.

pituitary gland Gland located at the base of the brain and responsible (among other jobs) for driving the ovaries in women and the testes in men by way of the pituitary hormones follicle stimulating hormone (FSH) and luteinizing hormone (LH), which are under the influence of gonadotropin releasing hormone (GnRH) from the hypothalamus. Composed of two parts, the adenohypophysis, or truly glandular part, in front, and the neurohypophysis, which is a down-growth of the brain, behind.

pituitary tumor A tumor, usually benign, of the pituitary gland, usually resulting in amenorrhea and anovulation. Often there is an increase (sometimes substantial) in serum prolactin. If the tumor is itself secreting prolactin it is called a prolactinoma. But other tumors can occur, some of which secrete other pituitary hormones. The tumor grows inside a confined space with walls of bone called the pituitary fossa: if it is still small and confined to the fossa we call the tumor a microadenoma; if it enlarges the fossa or pushes out of it, it is a macroadenoma, and is both more dangerous and capable of producing visual symptoms and headaches. Diagnosed on a CAT scan or a MRI scan. Prolactin-secreting microadenomas can usually be treated just with drugs (see hyperprolactinemia).

placenta That part of the products of conception apart from the fetus where blood from the fetus and from the mother come into intimate contact to exchange nutrients and waste. Composed of trophoblast. Together with the membranes (of the gestational sac) and the umbilical cord composes the “afterbirth”. See also decidua.

plasma glucose A measurement of sugar (glucose) in the blood plasma to detect diabetes, an occasional cause of recurrent miscarriages. Usually checked a few hours after a meal or, more formally, with a glucose tolerance test that involves a standard drink of glucose (after prior fasting) followed by serial measurements of plasma glucose over 3 hours.

PMS Either premenstrual spotting or premenstrual syndrome (see premenstrual tension, PMT).

PMSP See premenstrual spotting.

PMT See premenstrual tension.

polar body A tiny, compact packet of excess chromosomes discarded first by the primary oocyte as it becomes a secondary oocyte just before ovulation -- the first polar body, with 46 chromosomes; and second by the secondary oocyte immediately after fertilization (or after activation by other means) -- the second polar body, with 23 chromosomes. The polar bodies lie in the perivitelline space. The chromosome content of each polar body can be tested as part of a preimplantation diagnosis maneuver to infer whether the corresponding oocyte has an aneuploidy: an extra chromosome in the polar body means a chromosome not enough in the oocyte, and vice versa; this is called polar body analysis. See also meiosis.

polycystic ovaries (PCO) The full name (almost never used) is micro-polycystic ovaries: it’s a diagnosis best made on transvaginal ultrasound, with lots of medium-sized follicles visible around the rim of the ovaries; can be part of the polycystic ovary syndrome. (The “cysts” are not real cysts. Think of them as stalled follicles. They don’t need to be treated.) A very common condition: about 20% of women have it, though only a few women have the full syndrome.

polycystic ovary syndrome (PCOS) A syndrome that consists of polycystic ovaries associated with any clinical symptom or sign of too much male hormone effect, such as acne, excess body hair (hirsutism), or long or absent cycles (oligomenorrhea or amenorrhea). Often called polycystic ovarian disease in the US (PCOD).

polymerase chain reaction (PCR) A method of amplifying (increasing in number) a single piece of DNA (the stuff of genes) to get enough of it to analyze physically or chemically for DNA testing. A machine is used that uses alternate cycles of high temperature (to separate DNA’s two strands) and medium temperatures (to combine each of the two single strands with free nucleic acids to make new complementary strands), doubling the amount of DNA in the machine’s soup each cycle. A few hours in the machine automatically creates millions of identical DNA molecules from just one specimen. Needless to say, it’s extremely important that you start with the right bit of DNA, so you’re not inadvertently amplifying a bit of contamination! In the film Jurassic Park, PCR was used to amplify bits of dinosaur DNA recovered from the bellies of contemporary insects, which had been trapped and preserved for millions of years inside pieces of amber. A biopsy of a single cell from an embryo after IVF can, with PCR, produce enough DNA to test it for certain genes that cause serious genetic disease. See also preimplantation genetic diagnosis.

polymorphisms Forms of a gene (that is, alleles) that are too prevalent in the population to be called mutations or even, sometimes, to be regarded as abnormal. Often they confer an advantage in some special circumstance.

polyp A benign growth of tissue, usually of the lining of a hollow organ such as the intestine or the uterus. See cervical polyp and endometrial polyp.

polyploid A multiple of the haploid number of chromosomes in a cell other than the normal diploid state. Includes triploid (three times the haploid number, or 69 chromosomes) and tetraploid (four times the haploid number, or 92 chromosomes). The noun form of this adjective is polyploidy (the state of being polyploid).

polyspermic fertilization See polyspermy.

polyspermy Fertilization of an egg (a secondary oocyte) by more than one sperm (spermatozoon). In in vitro fertilization, more common if eggs are recovered that are either immature or overly mature. Evident later, with the appearance of more than two pronuclei. In natural conditions, a cause of a polyploid state in the embryo. See also triploid. Another name for it is polyspermic fertilization.

poor responder See low responder.

positive history If you have a positive history for a disease or symptom it means that you have or have had that disease or symptom. Contrast with negative history.

positive test 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.

postcoital bleeding (PCB) Bleeding after sex. Typically the result of abrasion of the cervix (which may be abnormal and you should have an examination and a PAP smear) or of trauma to the vagina. Sometimes due to a cervical polyp. PCB

postcoital contraception 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.

postcoital test (PCT) A test of: (1) receptiveness of the cervical mucus to sperm; and (2) sperm motility -- both of which are needed for the test to be a positive test. It’s essential that the test be done to coincide with ovulation, tested with a urinary LH kit or measurements of serum estradiol (high), serum LH (preferably high) and serum progesterone (still low), because the job description of the cervical mucus at other times is to be impenetrable to sperm (i.e. the PCT will be negative for normal reasons).

postimplantational embryopathy An abnormality of the embryo (or fetus) that arises after implantation of the embryo in the endometrium (the lining of the uterus). Might, sooner or later, cause a miscarriage or birth abnormality. Discussed in WebPage 8.

Predalon Alternative name for Pregnyl used in Germany.

predecidual reaction A partial confluence of stromal cells of the endometrium (lying between the endometrial glands), caused by prolonged exposure(10 days or more) to progesterone or a progestogen. See also decidual reaction.

preeclampsia 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.

pre-embryo A term sometimes used for the embryo or ovum from the stage of fertilized egg (or zygote) up to the stage of the morula. During this time any of the cells of the fertilized ovum can develop into a whole new embryo -- they are totipotent. As it becomes a blastocyst a proportion of the cells (the inner cell mass) commit to producing the embryo proper, while the remaining majority are destined to form trophoblast. Distinguishing pre-embryo from loose use of the term embryo has some value when debating the morality of embryo research, but it is not universal practice.

pre-embryo biopsy See embryo biopsy and preimplantation genetic diagnosis.

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

pregnancy rate 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.

pregnancy test 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). See also serum hCG.

Pregnyl Human chorionic gonadotropin (hCG) made by Organon.

preimplantation genetic diagnosis (PGD) Genetic diagnosis of an IVF embryo before embryo transfer. Made possible by removing one or two cells of the embryo (embryo microbiopsy). Typically performed on day 3 of embryo development in vitro, at the 8-cell stage, prior to compaction, or on day 5, as an expanding blastocyst. See also fluorescent in situ hybridization (FISH), comparative genomic hybridization (CGH) and polymerase chain reaction (PCR).

preimplantational embryopathy An abnormality of the embryo (or fetus) that arises before the embryo undergoes implantation in the endometrium (the lining of the uterus). Usually causes miscarriage. Discussed in WebPage 8

Premarin A mixture of estrogens in tablet form (from Ayerst Laboratories) with the reputation of being “natural’, though in reality extracted from the serum of pregnant mares (horses); the main human estrogen it contains is estrone.

premature labor The onset of labor, leading to delivery, before at least 37 weeks have elapsed since the last menstrual period. The more prematurely babies are born, the greater the difficulty they have surviving, even with expert care.

premature menopause When menopause occurs before the age of 40. See primary ovarian failure.

premenstrual biopsy (PMB) See premenstrual endometrial biopsy.

premenstrual endometrial biopsy 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 -- see the box, The endometrial clock, in WebPage 3. 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 jeopardizes an early pregnancy (namely an early implantation, before the pregnancy test or serum hCG has become positive). See also luteal phase defect.

premenstrual spotting A form of light intermenstrual bleeding consistently timed over a few days to a week before the period starts properly, although it might not happen every month. About 80 percent of the time it signals the presence of endometriosis, making it the most predictive symptom for this condition; about 10 percent of the time it means an abnormality of the uterus such as fibroids, an endometrial polyp or endometritis; the remaining 10 percent of the time there is no explanation found. It has nothing to do with premenstrual tension, which if present is a coincidence. For more on its association with endometriosis, see WebPage 15.

premenstrual syndrome See premenstrual tension.

premenstrual tension (PMT) A distressing group of symptoms usually timed for the lead up to a period, then relieved as menstruation takes place, although many women experience different timing; includes downheartedness or depression (certainly an absence of well-being), aggression, fluid retention and weight gain, painful breasts (‘mastalgia’), headaches and pain in the pelvis; caused by a periodic fall in the brain’s endorphins, in turn usually precipitated by falling levels of progesterone in the second half of the luteal phase, although similar symptoms often accompany the use of progestogens, especially in older women; may be better during superovulation cycles because of generally higher hormone levels, but this is not always the case and PMT at the end of an unsuccessful cycle of assisted conception is particularly hard to put up with. Usually treated (up to a point) symptomatically, with perhaps fluid tablets (diuretics) and analgesics, although it’s claimed that the drug Prozac has a specifically beneficial effect on mood, and encouragement of endorphin release with exercise can also be useful. Because progesterone and progestogens are the culprits, an operation to remove the ovaries (plus hysterectomy to simplify estrogen replacement therapy without needing progestogens) is usually curative, but drastic.

prenatal testing See chorionic villus sampling, amniocentesis and triple test.

preovulatory follicle A large, mature tertiary follicle that will respond to an adequate LH surge or injection of human chorionic gonadotropin (hCG) by undergoing ovulation, releasing its egg. Produces estradiol and, with exposure to LH or hCG, progesterone. See also Graafian follicle.

preovulatory Immediately prior to ovulation.

primary 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.

primary amenorrhea Amenorrhea when a woman has never had a spontaneous menstrual period, that is, a period not brought on by hormone treatment. See also primary.

primary follicle The first stage of growth or further development of the follicle, in which the egg is enclosed by a single layer of round-shaped follicle cells, which are multiplying. The majority of primary follicles undergo atresia; a minority develop into secondary follicles.

primary infertility Trouble getting pregnant (infertility) in someone who has never had a successful pregnancy (see primary. Although the exact definition can vary among gynecologists, in the book 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.

primary oocyte The form of the ovum, or egg, produced in the ovaries of fetuses by oogonia that have begun the first part of the cell division known as meiosis (by which the chromosomes will eventually halve in number). Persists into childhood and adult life by containment in follicles. Gives rise to a secondary oocyte and the first polar body just before ovulation. See also in vitro maturation.

primary ovarian failure Failure of the ovaries to produce enough follicles, because of a problem in the ovary itself, and resulting in depletion of eggs before the age of 40 years (known as premature menopause, a cause of secondary amenorrhea), or maybe even before the age puberty is expected (causing failure of puberty to happen, including primary amenorrhea). Sometimes occurs in spite of good numbers of primordial follicles that (inexplicably, so far) won't develop (see the box, The resistant ovary syndrome, in WebPage 11). The younger the woman, the more likely that an aneuploidy will be found if a karyotype is done on blood or on a biopsy of the ovary. Estrogen replacement therapy is important to prevent general jeopardy to health, including prevention of osteoporosis. See also Turner syndrome, triple-X syndrome, fragile-X syndrome, primary.

primary spermatocyte The form of the sperm cell (or male gamete) at the first stage of spermatogenesis, by which spermatogonia enter meiosis to start to reduce the number of chromosomes for the more mature sperm cells (the spermatozoa) that will eventuate.

Primolut N The progestogen norethisterone acetate (UK, Australia) or norethindrone acetate (US) made by Schering.

primordial follicle The resting, unstimulated stage of the follicle, in which the egg (as a primary oocyte) is enclosed by just a few thinly stretched follicle cells. Primordial follicles persist in the ovary from fetal life to the time of menopause, declining in number every day during this time, as some start to develop into primary follicles, most of which then are lost through the process of follicular atresia. What the stimulus or signal is for a particular primordial follicle to start growing remains completely unknown (it is independent of FSH).

PRL See prolactin.

Profasi Human chorionic gonadotropin (hCG) made by Serono. Nowadays highly purified and should be suitable for subcutaneous injection.

professionalism In the book, the practice of maximizing the involvement of a client or patient seeking the service of a professional in making decisions that will directly affect them.

progesterone 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. See also estrogen, progestogen and serum progesterone.

progestin See progestogen. Strictly, the term progestin encompasses progesterone too (i.e. “progestins” = “progesterone” + “progestogens”).

progestogen A progesterone-like substance, usually more active when given by mouth than natural progesterone is. Used with an estrogen in the birth control (oral contraceptive) pill. Commonly used examples have a structure like progesterone itself (e.g. medroxyprogesterone acetate, or Provera; cyproterone acetate, or Androcur) or have a structure distantly related to the male hormone testosterone (e.g. norethisterone, or Primolut N; norgestrel)

Progynon C Schering's preparation of ethinyl estradiol.

prolactin (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, read the box, The fishy side of prolactin. See also bromocriptine, dopamine, hyperprolactinemia and serum prolactin.

proliferative phase The phase of development of the endometrium during which, after the menstrual phase, the endometrium grows to regain thickness under the influence of estradiol (therefore it corresponds in time with the follicular phase in the ovarian cycle).

pronuclear stage transfer (PROST) A form of assisted conception in which in vitro fertilization (IVF) is used to produce fertilization of one or more recovered eggs (oocytes). Useful if the potential fertilizing ability of sperm (spermatozoa) is in doubt. Transfer is made on the day after egg retrieval and IVF, before the fertilized egg divides (it’s at the pronuclear stage); the transfer is made to the fallopian tube to obtain advantages similar to gamete intrafallopian transfer (GIFT) and is made possible by laparoscopy (with anesthesia) or, less successfully, by transvaginal ultrasound (without anesthesia). Synonymous with zygote intrafallopian transfer (ZIFT). See also pronucleus.

pronucleus A visible “blob” (or vacuole) -- there are usually two of them -- inside an egg that has undergone fertilization or activation by other means, and enclosing the chromosomes from the oocyte (the female pronucleus) and from the sperm (the male pronucleus). Plural: pronuclei. If three pronuclei are observed, the chances are that two sperm have entered the egg (polyspermy).

PROST See pronuclear stage transfer.

prostaglandins Substances, first isolated from the prostate gland’s contribution to semen, now known to be universally present throughout the body, being especially produced during inflammation (when they cause pain). Drugs that stop prostaglandins being produced are used as analgesics (so called nonsteroidal anti-inflammatory drugs, or NSAIDs, which are useful also in minimizing contractions of the uterus in dysmenorrhea and premature labor.

prostate gland The male sex gland located just below the bladder, in front of the rectum, through which the urethra runs; it contributes secretions to the semen.

prothrombin G20210A A polymorphism for the blood clotting factor prothrombin that makes coagulation occur more readily, therefore causing thrombophilia.

Provera The progestogen medroxyprogesterone acetate, made by Upjohn.

pseudohermaphrodism Synonymous with intersex, except that intersex also includes true hermaphrodism.

Puregon Recombinant follicle stimulating hormone made by Organon. Called Follistim in the US. Generically known as follitropin beta.

PureSperm A laboratory medium approved for separating human sperm, made by Nidacom.

pyosalpinx A fallopian tube obstructed at its outer, fimbrial end and containing pus as a result of acute salpingitis. If the infection does not settle promptly with antibiotics, and becomes an abscess, surgical drainage can be needed (performed at transvaginal ultrasound in the operating room or at laparoscopy, perhaps with a salpingectomy).

 

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qualitative Something you can’t put a number on to give it its meaning or value, such as suffering. See also hazard. Opposite to quantitative.

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

Quetelet index See body mass index.

 

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Recagon Alternative name for Puregon used in India.

receptor Consider a hormone to be a key, then a receptor is the lock. One is useless without the other. A hormone cannot act on a cell (or a tissue) unless the cell displays a receptor, which is linked to the internal machinery of the cell.

recessive inheritance A pattern of inheritance of a characteristic (such as blue eye color) or abnormality (such as congenital absence of the vas deferens) in which two abnormal genes or alleles are needed to confer the characteristic or abnormality, in contrast to dominant inheritance, which requires just one abnormal gene. See also homozygous. In the case of alleles found on X-chromosomes but not on the smaller Y-chromosomes, a recessive gene will be unopposed (and so will act as a dominant gene) in males, 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.

recombinant follicle stimulating hormone (rFSH) Follicle stimulating hormone derived from genetic engineering instead of being extracted from the urine of postmenopausal women (human menopausal gonadotropin, or hMG) or from the pituitary glands of cadavers (human pituitary gonadotropin, or hPG). Produced and marketed by the two pharmaceutical companies Organon (as Puregon), or Fertinex in the US and Serono (as Gonal-F) to replace their hMG preparations. Has the advantage over hMG (and its purified derivatives) of being standard in biological structure and activity, and of not being of a human source (hPG -- but not hMG -- having been implicated in transmission of Creutzfeldt-Jakob disease).

recombinant FSH See recombinant follicle stimulating hormone.

recombinant LH See recombinant luteinizing hormone.

recombinant luteinizing hormone (rLH) Luteinizing hormone derived from genetic engineering technology instead of being extracted from the urine. Marketed by Serono as Luveris.

recruit See follicular recruitment.

rectum Connects the large bowel (the colon) to the anus; lies behind the vagina in women.

recurrent miscarriages A series of three or more consecutive miscarriages.

regeneration and tolerance factor (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.

relative infertility Synonymous with subfertility.

relative risk The chance of having something or being affected by something compared with people in a comparable situation. Usually given as a ratio, a proportion or a percentage (as in the chance of having endometriosis; if your sister has it, you have a relative risk of 7:1 -- or seven times the risk -- compared with the general population of women of the same age; your relative risk of developing cancer of the ovaries if you’ve accumulated 10 years on the oral contraceptive pill is 1:5, 0.2 or 20.

relaxin An insulin-like protein with quite different functions. As the name suggests, tissues soften, relax or give-way upon exposure to it. Produced, for example, in the wall of the preovulatory follicle before ovulation, by the decidua to calm the myometrium of the pregnant uterus, and by the corpus luteum and the placenta to soften the ligaments of the pelvis in preparation for labor and childbirth.

reproductive cloning The use of somatic cell nuclear transfer or embryo splitting (see cloning) 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).

Repronex Highly purified human menopausal gonadotropin made by Ferring. Called Menogon or Menopur outside the US.
responsibility See accountability.

resistant ovary syndrome See primary ovarian failure.

rete testis Tiny ducts (about 20 in number) connecting the testicular tubules with the epididymis.

retroflexed A backward angle of the fundus of the uterus in relation to the direction of the cervix. Usually only occurs when the uterus is retroverted. Opposite to anteflexed.

retroflexion See retroflexed.

retrograde ejaculation Ejaculation in which semen, instead of spurting out from the penis during male orgasm, spills upwards into the bladder. Usually has a medically important cause, which requires investigation. Treatment can be successful by isolating spermatozoa from the urine and carrying out some form of assisted conception, such as assisted insemination or in vitro fertilization.

retroversion See retroverted uterus.

retroverted Refers to the position of the uterus when it is tilted backward in relation to the direction of the vagina. A retroverted uterus is not always abnormal. Sometimes, however, a uterus can be pulled into a retroverted position by endometriosis affecting the uterosacral ligaments. A sharply retroverted uterus can cause pain during and after sex (dyspareunia). Opposite to anteverted. See also transvaginal ultrasound.

retroverted uterus A uterus that lies more towards the back than the front. Retroversion of the uterus may be normal and, of itself, this is not a cause of infertility; rarely it can repeatedly get in the way during sex and cause pain, in which case there are operations available to bring it forward, out of the way. Retroversion can also develop from scarring caused by endometriosis, in which case there can be pain with sex (dyspareunia) and infertility (caused by the endometriosis).

rFSH See recombinant follicle stimulating hormone.

right The reciprocal, or other side, of a duty or obligation, often conferred by society on the basis of equity or consistency, and matched either by intuitive duties or by conferred obligations.

risk Chance -- expressed as a ratio, proportion or percentage. If the word is unqualified, it usually means absolute risk (the actual risk in a group of the population), in contrast to relative risk (which measures one person’s risk compared with another person’s). See also hazard.

ROSI See round spermatid injection.

ROSNI See round spermatid nuclear injection.

round spermatid injection (ROSI) Experimental form of testicular sperm extraction (TESE) followed by intracytoplasmic sperm insertion (ICSI) in which a round (very immature) spermatid is isolated for injection into the egg (or oocyte). Seems to be less successful than a similar procedure in which the nucleus is isolated from the spermatid and used instead (see round spermatid nuclear injection). Not recommended clinically.

round spermatid nuclear injection (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.

r-selection A reproductive strategy where survival of a species is optimized by explosive increases in numbers of animals whenever environmental circumstances are favorable; typically seen with small animals that reach sexual maturity quickly, which reproduce just once but with many progeny, and which do not need to tend to their progeny for very long (if at all) after birth. In extreme cases (seen in many lower animals such as insects), death of the father follows impregnation and death of the mother follows parturition (or giving birth). The opposite reproductive strategy to K-selection.

RTF See regeneration and tolerance factor.

Rubin’s test See tests for tubal patency.

rudimentary horn The small part of a bicornuate uterus in which one side is very small; with regard to the side that is bigger (see unicornuate uterus), it can be called communicating or non-communicating depending on whether it has a cavity that joins with the main endometrial cavity. See also cornual pregnancy.