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danazol A hormonal drug used for treating endometriosis. Related to male sex hormones (it's a weak androgen), it has occasional androgenic side effects, including weight gain and increased muscle bulk (it's also an anabolic steroid), and increased facial hair (hirsutism); less commonly their can be deepening of the voice or enlargement of the clitoris. For the details of its correct and incorrect use, see WebPage 16, especially the box, Danazol mischief. Made by Sanofi Winthrop as Danocrine.
Danocrine See danazol.
day 3 FSH See depletion of eggs and serum FSH.
Decapeptyl A GnRH-agonist, made by Ipsen Biotech as triptorelin. Administered by a monthly injection.
decidua 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).
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.
decidual reaction 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. See also decidua and predecidual reaction.
delta F508 The commonest of the alleles to result in cystic fibrosis (when two delta F508 alleles are present) or (can occur when one F508 allele is present in a man). A woman heterozygous for this gene (with one F508 allele) will be a carrier for cystic fibrosis (and for CBAVD) but will herself be otherwise normal. There are however many other faulty alleles that can also contribute to these clinical conditions. The most common alleles can be looked for at preimplantation genetic diagnosis (PGD).
deontological ethics A set of ethical beliefs, in which principles and values are seen by adherents to be self-evident and not in need of more basic proof. The ethical principles are duty-binding, innately known, and by nature resistant to change. For practical application, and a contrast to teleological ethics and utilitarian ethics, read the box, Ethics: Moral imperatives, outcomes and equity, in WebPage 26.
deoxyribonucleic acid See DNA.
depletion of eggs The natural process in which the older the female fetus, girl or woman gets the fewer are the eggs (as primordial follicles) left in the ovaries; the huge majority of eggs are lost because of atresia, only a tiny fraction by ovulation. Before the eggs are depleted there is a mild or moderate elevation in serum FSH when measured during the menstrual phase (often called a day 3 FSH. When the eggs are more or less depleted there will be primary ovarian failure and, in women who have had periods, the menopause will take place, perhaps prematurely (premature menopause). Infertility, however, usually precedes total egg depletion by up to 10 years. See also mitochondrion and oopause.
DHT See dihydrotestosterone.
DI See donor insemination.
Diane-35 A formulation of the oral contraceptive pill that contains, as well as an estrogen, the progestogen known as cyproterone acetate, which is particularly effective at blocking the effects of male hormones on the skin. Made by Schering.
diathermy Use of a high voltage, high frequency electric current to coagulate or evaporate tissue during surgery. Useful because it can be used during laparoscopy, particularly for stopping bleeding (by coagulation) and for treating endometriosis (by evaporation).
dihydrotestosterone (DHT) The most active male sex hormone or androgen; formed in target tissues from testosterone (which is the main form of androgen circulating in the blood). Testosterone must be converted to DHT before it can do its job (the enzyme for which is 5-alpha reductase, and a deficiency of which is a cause of intersex.
dilatation and curettage Before curettage (of the uterus), the cervix is dilated to admit the curette. Sometimes abbreviated, D & C.
Dimetriose See gestrinone.
diploid The full, normal complement of chromosomes, numbering 46 (as 23 pairs). See also haploid. The noun form of this adjective is diploidy (the state of being diploid).
distributive justice Justice dispensed in the community to confer maximum value to those in need through the notions of fairness and consistency.
dizygotic twins Twins formed from two fertilized eggs, or zygotes; non-identical twins.
DNA The stuff of which genes are made. DNA is an abbreviation of deoxyribonucleic acid, a molecule made of a variable sequence of units, the nature and order of which forms the genetic code. DNA is located chiefly in the chromosomes, which form a cell’s nucleus. A small amount of DNA (coding for about 13 genes) is found in the mitochondria (for which see also mtDNA).
DNA testing Testing for the presence or absence of a particular sequence of DNA using molecular methods such as the polymerase chain reaction or, increasingly, with DNA arrays, or DNA chips.
dominant follicle The preovulatory follicle, or Graafian follicle, that has won the responsibility for producing estradiol for the rest of that particular ovarian cycle. Chosen by the end of the first week of the follicular phase. Its destruction (whether accidental or intentional) means that a new follicular phase must start, with ovulation two weeks later, whereas destruction of one of the tertiary follicles before one has become dominant causes no interference with the timing of ovulation for that cycle.
dominant inheritance A pattern of inheritance of a characteristic (such as brown eye color) or abnormality in which just one gene or allele is needed to confer the characteristic or abnormality, in contrast to recessive inheritance, which requires two abnormal genes. See also heterozygous.
donor insemination (DI) Assisted insemination in which semen from a sperm donor (who is not the husband) is used.
Dostinex See cabergoline.
Down's syndrome 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.
DUB See dysfunctional uterine bleeding.
duration of infertility 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.
duty A moral compulsion for ethical action that is innate. The basis for deontological ethics. See also suffering. Generally synonymous with obligation. In WebPage 26, a duty is considered innate or intrinsic (it originates inside you), whereas an obligation is imposed extrinsically, by the enforcement of others' rights (it originates outside you).
Dysfunctional Uterine Bleeding (DUB) Heavy bleeding from the uterus. See anovulatory dysfunctional bleeding (often painless and irregular) and ovulatory dysfunctional bleeding (usually regular and can be associated with dysmenorrhea).
dysmenorrhea Painful menstruation. Can be primary, present in teenagers, generally in spasms around the start of the period; or it can be secondary, developing as a woman gets older, and then typically lasting more than a day or so into the period, with prolonged aching as well as spasms. Primary dysmenorrhea might have no medical importance beyond the suffering the pain causes, and typically gets better as a woman reaches her 20s; severe or persistent cases, however, warrant investigation. Secondary dysmenorrhea can signify, for example, endometriosis, fibroids, adenomyosis or peritubal adhesions.
dyspareunia Painful sexual intercourse that persists after the first few times or which develops after months or years of painless sex.
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eclampsia See preeclampsia.
ectodern The “upper” layer of the embryo as the inner cell mass forms a circular disk two cells thick, giving rise with further embryonic development to the skin, brain and spinal cord. Synonym: epiblast. See also endoderm and mesoderm.
ectopic pregnancy rate 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.
ectopic pregnancy 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). See also heterotopic pregnancy and cornual pregnancy.
efferent ducts Fine passages in the rete testis conducting sperm cells (spermatozoa) from the tubules of the testis to the epididymis.
egg General term for oocyte.
egg depletion See depletion of eggs.
egg donation A form of collaborative reproduction comparable in some ways to sperm donation (see donor insemination), but different in that eggs for donation are much harder to obtain physically than ejaculated sperm are; generally the egg donor undergoes all the steps needed for in vitro fertilization up to the stage of egg retrieval.
egg pick-up See egg retrieval.
egg retrieval Procedure for obtaining eggs (oocytes), involving the passing of a needle into a mature (or preovulatory follicle, either directly at laparoscopy or (more usually) via the vagina guided by transvaginal ultrasound.
electrocautery See diathermy.
embryo The word is used loosely to describe everything from a fertilized egg (or zygote) to a fetus, including the embryo. What nowadays we call the embryo has for long been called the ovum by professional embryologists!
embryo biopsy A biopsy, or removal of one or two cells, from an early IVF embryo for preimplantation genetic diagnosis after in vitro fertilization.
embryo transfer (ET) Procedure by which the embryo is placed in the uterus or into the fallopian tube after in vitro fertilization.
embryonic stem cells See inner cell mass and stem cell.
embryopathy Literally, pathology of the embryo (or fetus). Can underlie a miscarriage or, if it reflects are more or less permanent state, can cause unexplained infertility.
empathy More than feeling compassion or sympathy “for” another person, empathy puts you in their shoes to feel “with” them or “as one” with them. First used in English in the early twentieth century to translate the German psychoanalytic term Einfühlung, meaning “to feel as one with”, though in practice more closely translating the German Mitgefühl, “to feel with” someone.
empirical An awkward adjective that can have contrary meanings in medicine. The word comes from the Greek for experience. On the one hand, empirical medical practice is that which is based only on observation and experiment (praiseworthy); on the other, it can refer to medical practice that’s based on very personal experience without taking scientific principles into account (not praiseworthy); at worst it refers to treatment that’s chosen on no other basis than: “Let’s see if it might work’. In this book I use it in its first sense unless I draw attention to a contrary use of it by others.
endocrine disrupter A natural or pollutant substance in the environment possibly capable of acting -- alone or in combination with other substances -- as an estrogen or as a blocker of androgens during development of the fetus. Suspected of causing endometriosis and oligospermia in later life.
endocrinology The study of hormones, including their production, their action and their excretion.
endoderm The “lower” layer of the embryo, as the inner cell mass forms a circular disk two cells thick; with further embryonic development it gives rise to the digestive tract and its glands. Synonym: hypoblast. See also ectoderm and mesoderm.
endometrial atrophy Diminishment of the endometrium through lack of support by, especially, the hormone estrogen or by the loss, through chronic endometritis and/or injury at curettage under abnormally low estrogen conditions, of subsequent receptiveness to estrogen. Can cause light periods hypomenorrhea or absent periods amenorrhea. See also Asherman's syndrome and intrauterine adhesions.
endometrial biopsy See premenstrual endometrial biopsy.
endometrial cavity The space inside the uterus lined by the endometrium.
endometrial hyperplasia Overgrowth of the endometrium, caused usually by prolonged action of estrogen unopposed by progesterone (i.e. prolonged anovulation), as is the case in, particularly, the polycystic ovary syndrome. Potentially dangerous, because it can turn to cancer of the endometrium. Can be suspected by an echogenic appearance of the endometrium on transvaginal ultrasound and is confirmed by pathological examination of tissue obtained at curettage.
endometrial polyp 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.
endometrial resection An operation performed at hysteroscopy to treat menorrhagia by intentionally producing endometrial atrophy and intrauterine adhesions.
endometrial stroma 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). See also decidua.
endometriosis A common condition in which tissue like the lining of the uterus (the endometrium), grows somewhere else, sometimes causing dysmenorrhea, premenstrual spotting, infertility, dyspareunia and ovulatory dysfunctional uterine bleeding. See also unexplained infertility.
endometritis Inflammation of the endometrium (the lining of the uterus). Can be acute or chronic. Not related to endometriosis.
endometrium The lining of the uterus, which contains the endometrial glands and the endometrial stroma. Distinct from the myometrium.
endorphins Opium-like substances produced naturally in the brain, which give a feeling of well-being. Production of endorphins is stimulated by many natural circumstances, and also by profound exercise (to which people can become “addicted”!). Depressed in premenstrual tension.
environment The physical, chemical, biological and social milieu in which we live. See also congenital and endocrine disrupter. This environment is sometimes called the external environment, in contrast to an internal environment that might describe the physical and chemical milieu inside the body, around a particular organ, tissue, cell or intracellular organelle.
enzyme A protein found in cells and secretions that acts as a catalyst, greatly promoting a chemical transformation for a special purpose. Enzymes are important in every aspect of biology, including the production (and destruction) of hormones.
epididymal sperm aspiration See microscopic epididymal sperm aspiration (MESA).
epididymis A finely coiled tubular structure, lying next to each testis in the scrotum, which connects the testis to the vas deferens, and through which sperm cells (or spermatozoa) pass and gain in maturity.
ERT See estrogen replacement therapy.
ES cells Embryonic stem cells.
eSET Elective single embryo transfer. Choosing to have just one embryo transferred after in vitro fertilization 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 minimizing the risk of multiple pregnancy, which carries a higher risk of miscarriage and stillbirths.
estradiol The most powerful natural estrogen. Produced by the ovarian follicle and corpus luteum in women, and (to a small extent) by the Sertoli cells in men. Also produced by fat cells (through conversion of testosterone) in older women, especially after the menopause. See also serum estradiol.
estriol A weak estrogen. Increased in pregnancy, especially late pregnancy. See also triple test.
estrogen The general name for one of the two principal female sex hormones (the other is progesterone), responsible for stimulating growth of the female reproductive system (the vagina, the cervix, the uterus and the fallopian tubes) and growth of the breasts. The main estrogen is estradiol, produced by: the developing follicle (and to a lesser extent by the corpus luteum) in the ovary; by the trophoblast of the placenta; and by the body’s fat tissues (through conversion from male sex hormones, or androgens, in the blood). After the menopause the main estrogen is the weaker one, estrone, largely derived from conversion by the body’s fat of the weak androgen androstenedione.
estrogen replacement therapy (ERT) The therapeutic use of estrogen to stop the effects of menopause after the ovaries have been removed or have stopped functioning. If the uterus is still present the hormone regimen must include at least 11 days’ progestogen usage each month, or there will be a risk of endometrial hyperplasia and hence endometrial cancer.
estrone A weak estrogen, which needs to be converted (in target tissues such as the endometrium) to the strong estrogen estradiol before, as a hormone, it causes an estrogen effect. The main estrogen in blood after the menopause. Formed from estradiol when that hormone in tablet (or oral) forms is absorbed across the intestines. Abbreviated E1.
ethical practice committee A socially derived, multidisciplinary committee of a hospital. It meets irregularly, often at short notice, to help in the making of ethically difficult clinical decisions aimed at ascertaining and preserving the patient’s best interest. In the US generally called an ethics committee.
ethics committee A mandated committee of an institution (hence institutional ethics committee, or IEC, or human research ethics committee, or HREC) that conducts medical research. It meets regularly and is composed of specialist and lay individuals who consider the ethical implementation of protocols for research, according to the requirements of the 1975 Declaration of Helsinki (on clinical research and human experimentation) and any other official determinations relevant to the particular environment of the researchers. Its purpose is to gauge and to minimize risks run by the subjects of research. Its decisions are usually binding on researchers. In the US this committee is called an institutional review board, or IRB. In the US the term ethics committee denotes a committee distinct from an IRB that considers clinical ethical matters (see ethical practice committee.
ethics A set of principles and values that govern behavior to accord with a notion of morality. See especially deontological ethics, teleological ethics and utilitarian ethics, and also see autonomy, beneficence, non-maleficence, justice and suffering. The ethics of assisted reproductive technology, collaborative reproduction, the doctor-patient relationship, informed consent and human embryo research are much debated.
ethinylestradiol Orally effective form of estradiol that resists being converted to estrone after ingestion. Generic (‘no frills’) name for Estigyn and Progynon C.
expanded blastocyst The last stage of development of the blastocyst before it hatches out of the zona pellucida prior to implantation.
extravillous trophoblast The outermost layer of trophoblast, produced by cytotrophoblast where there is direct contact with maternal decidua rather than blood. The EVT cells travel into the decidua, reacting with NK cells and invading maternal blood vessels feeding the placenta, softening the walls and replacing the lining with fetal tissue, a process called “conversion”. Also known as interstitial or intermediate trophoblast.
extra-Y-chromosome syndrome SA trisomy with a karyotype of 47,XYY -- i.e. a male with an extra Y-chromosome. Affected men tend to be tall. Surveys of penal institutions have indicated a higher than expected frequency, implying that affected men are at increased risk of being criminals. This assertion is controversial.
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factor V Leiden A polymorphism for blood clotting factor “five” that makes coagulation occur more readily, therefore causing thrombophilia. Pronounced “Layden”
factor XIII “Factor 13”. A component of the coagulation system. See fibrinogen.
fallopian tube The hollow organ, about 10 to 12 centimeters long, that effectively joins the ovary to the uterus on each side. Composed of the fimbrial end, the ampulla, the isthmus and the interstitial segment.
falloposcopy Looking inside the fallopian tube with a tiny (half a millimeter diameter) flexible, fiberoptic instrument, from the direction of the uterus. See also salpingoscopy.
fecundability 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 (explained in Appendix 1, 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. See also normal monthly fertility and cumulative chance of pregnancy
fertilization Entry of a sperm cell into an egg: their “marriage’. The egg is activated by this event, so that: (1) “cortical granules“ are expelled that stop further sperm binding to the egg; (2) the second division of meiosis is completed, with expulsion of the second polar body; and (3) the machinery of the egg is got going, which will form pronuclei of the male and female chromosomes prior to syngamy.
Fertinex Highly purified Metrodin, with no residual luteinizing hormone, thus equivalent in activity to recombinant FSH. Called Metrodin HP outside the US. Made by Serono.
A controversial and emotionally hazardous way of dealing with a higher-order
multiple pregnancy (such as quadruplets, quintuplets, or higher) in
which, because 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,
fetus An unborn baby. The product of conception from the time the embryo is fully formed (from head to limbs -- about 8 weeks from the last menstrual period) -- until delivery.
fibrin A polymer that is formed from the circulating protein fibrinogen when blood clots (see coagulation system). Also important in the formation of the placenta, so abnormalities of fibrinogen can cause recurrent miscarriage.
fibrinogen A very soluble protein found in the blood that forms the progressively less soluble protein fibrin when blood clots, through the action, first of thrombin and then of factor XIII. See also coagulation system.
fibroid A benign “tumor” of the muscular wall of the uterus (the myometrium). More common with increasing age, but can occur in women in their twenties. Can be single or multiple, and can be located on the outside of the uterus (a subserous fibroid), within the wall of the uterus (an intramural fibroid), or protruding into the cavity of the uterus (a submucous fibroid). The closer it is (or they are) to the endometrial cavity, the more likely it is that a fibroid will disturb reproduction (either as miscarriages or sometimes as infertility) and disturb menstrual bleeding. Surgery for removal of a fibroid, or myoma, is called a myomectomy.
fimbria Latin for a fringe, particularly the fringed, open end of the fallopian tube referred to as the fimbrial end. Plural: fimbriae.
fimbrial end Also “fimbriated end’: the open, outside end of the fallopian tube in contact with the surface of the ovary, from which it “picks up” the ovulated egg from the ruptured follicle. It’s composed of delicate fimbriae -- finger-like projections of the tube lined by cells with tiny hairs (cilia), which beat towards the inside of the tube, carrying the sticky cumulus mass containing the egg into the ampulla before fertilization. Easily damaged by infection (salpingitis) or careless surgery, after which it may be blocked, resulting in a hydrosalpinx, or have its correct movement inhibited by adhesions.
fimbriectomy An operation for sterilization or “tubal ligation” in which the fimbrial end of each fallopian tube is removed. It has a higher failure rate than most other sterilization 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 jeopardize success with in vitro fertilization (see the box, Hydrosalpinx: reintroducing a villain, in WebPage 20, and the microsurgery operation to reverse it, salpingostomy, is much less often followed by pregnancy than tubal anastomosis operations are.
fimbriolysis Microsurgery of the fallopian tube’s fimbrial end, involving careful dissection of fimbriae that have become stuck together from adhesions. Generally gives a better outcome than salpingostomy (which must be resorted to if the fimbriae are too damaged to dissect).
FISH See fluorescent in situ hybridization.
fluorescent in situ hybridization Known as “FISH”. A form of DNA testing for genetic diagnosis in which a special region of a chromosome is stained with a dye that emits colored light when exposed to ultraviolet light. For example, a marker for chromosome 21 will normally show two spots of light, whereas three spots of light would indicate trisomy 21 (Down syndrome). Useful because the technique is accurate with just one cell, making diagnosis possible in an IVF embryo before transfer (see preimplantation genetic diagnosis), and speeding up prenatal diagnosis while awaiting a full karyotype. Being replaced in some labs by comparative genomic hybridization.
foetus See fetus. For a discussion on the spelling, see the box, Fetus or foetus?
follicle aspiration Egg retrieval procedure for obtaining eggs (oocytes), involving the passing of a needle into a mature (or preovulatory follicle), either directly at laparoscopy or (more usually) via the vagina guided by transvaginal ultrasound.
follicle Normal structure in the ovary that contains the egg, or oocyte. All are formed as primordial follicles before birth and remain microscopic in size until growth starts (folliculogenesis), a month or two before the cycle in which the particular follicle will be a candidate to ovulate. About 3 mm in diameter at the start of a cycle, and about 2 cm in diameter when ready to ovulate. The follicle makes more and more estrogen (particularly estradiol) as it grows. In ovarian monitoring for assisted conception, the number growing and their rate of growth are monitored by transvaginal ultrasound. See also primary follicle, secondary follicle, tertiary follicle, preovulatory follicle or Graafian follicle, atretic follicle and ovulation.
follicle cells Cells of the follicle that surround the egg (the oocyte). An increase in number is what causes the follicle to grow. In tertiary follicles they are responsible for converting androgens (from surrounding ovarian thecal cells) into estrogens, particularly estradiol. A tertiary follicle’s cells are also called granulosa cells.
follicle stimulating hormone (FSH) The hormone, or gonadotropin, produced by the pituitary gland that in women stimulates the tertiary follicle to grow; in men it stimulates spermatogenesis. Obtained from human sources in a mixture with luteinizing hormone (LH) as (1) human menopausal gonadotropin (hMG), extracted from the urine of women who have been through the menopause (Humegon, Metrodin and Pergonal); and (2) human pituitary gonadotropin (hPG), from human pituitary glands removed at autopsies (now obsolete). Today, pure FSH is made synthetically with gene technology (recombinant FSH), such as Gonal-F and Puregon. See also serum FSH.
follicle tracking Serial transvaginal ultrasounds of the ovary during the follicular phase to track the growth of one or more tertiary follicles, accompanied usually by serial estimations of serum estradiol, serum LH and serum progesterone, for the two-fold purpose of estimating follicular maturity (to time intercourse, a mid-cycle-dependent investigation such as a postcoital test, or an egg retrieval) and identifying the onset of the LH-surge, which can affect the timing of the intervention. Sometimes accompanied by injection of human chorionic gonadotropin to trigger ovulation at a precisely anticipated time.
follicular atresia The process by which a primary follicle or a tertiary follicle stops growing, leading to disappearance (apoptosis) of its follicle cells and the oocyte, or egg, they contain. Such a follicle is called an atretic follicle. See also follicular recruitment.
follicular phase The part of the ovary’s monthly cycle before ovulation, dominated by the presence of firstly, a cohort of growing tertiary follicles, then the dominant follicle, and the estradiol these follicles produce. Normally around 14 days in length, but quite variable, often being much longer for the first few menstrual cycles after the first period (menarche), and typically getting shorter in the months or years leading up to egg depletion and menopause. Corresponds with the proliferative phase of the endometrial, or menstrual cycle.
follicular recruitment A follicle is “recruited” at two distinct stages of development. Early or continuous recruitment refers to the ongoing, continuous recruitment of primordial follicles to start their growth and become antral follicles, a process that is independent of major hormones, starts before birth and ends when there are no follicles left, this taking place around the time of menopause. Cyclical recruitment refers to the much later recruitment of medium-sized tertiary follicles into the ovarian cycle due to a temporary elevation of follicle stimulating hormone, which occurs at the end of each luteal phase, thus initiating a new follicular phase; the group of “recruits” susceptible to this late recruitment is called a cohort. Time-wise for a particular follicle, the two episodes of recruitment occur 8 months apart: in other words, it takes 8 months for a follicle to grow from its resting state before it can have a chance of making estrogen and then undergoing ovulation. Not all early-recruited follicles undergo later cyclical recruitment: some are lost through early atresia, many reach the stage at which they could be cyclically recruited at a stage when FSH is low (most stages of the ovarian cycle) and undergo atresia then. Readers will appreciate that ovulation induction, including intentional superovulation, can have no effect on the rate at which follicles are used up in ovaries or on the age at which menopause will occur (the different recruitment points involved are 8 months apart, with the early recruitment point governing the rate eggs are used up and the late recruitment point deciding how many follicles can respond to provide useable eggs.
folliculogenesis Strictly, the process by which follicles are first formed in the ovaries before birth; in the woman, it means the growth of a primordial follicle into an early tertiary follicle -- a transition that confers receptiveness of the follicle to follicle stimulating hormone (FSH) The stimulus for initiation of follicular development and its timing for individual follicles remains a mystery.
Follistim Recombinant follicle stimulating hormone made by Organon. Called Puregon in Europe, Australia and Asia. On an equivalent dose basis, produces serum FSH that are somewhat slower to rise than with the use of hMG preparations, but which are ultimately higher: in other words, follicles and serum estradiol levels take a little longer to respond than they do to Humegon, but the number of mature, preovulatory follicles available for egg retrieval is the same or more. I find that 200 U (units) of Puregon per day produces a similar result to 225 U of Humegon or Metrodin. Generically known as follitropin beta.
follitropin Generic name for recombinant FSH, as found in Gonal-F (or follitropin alpha) and Puregon (Follistim), or follitropin beta. Although there are slight differences in the two preparations, their clinical action is equivalent.
fragile X syndrome The commonest cause of severe mental retardation in males, caused by a long “triple repeat sequence” in a part of a gene for intelligence located on an X-chromosome, rendering this sex chromosome susceptible to breakage, which can be revealed either in a karyotype performed under special laboratory conditions or using a special PCR DNA test; females have two X-chromosomes and so may be carriers for this devastating condition, which will affect one-in-two of their male children; the carrier state in females can have clinical effects, namely a susceptibility to reduced numbers of ovarian follicles and hence primary ovarian failure and premature menopause, so should be looked for before assisted conception attempts are made in these clinical circumstances.
free androgen index Not often carried out at no cost, “free” here means the androgen (testosterone) in blood that is not bound to carrier proteins such as sex hormone binding globulin, so it’s immediately available for action in the tissues. A more sensitive test than serum testosterone and likely to be increased in the polycystic ovary syndrome. An indirect measure of serum free testosterone, which can be performed instead.
free testosterone index See free androgen index and serum free testosterone.
FSH See follicle stimulating hormone.
fundus The body, or the main part, of the uterus (I.e. the part of the uterus that is not cervix). Sometimes refers to the dome-shaped topmost part of the uterus.