IVF, or fertilisation of the egg (the secondary oocyte) by a sperm (a spermatozoon) in vitro, i.e. in the laboratory. Necessary if the fallopian tubes are diseased or missing; useful if sperm fertilising capacity is doubtful, because evidence of fertilisation can be seen before the egg is transferred as an embryo.

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.

An in vitro fertilisation manipulation in which a small opening is made in the zona pellucida of the early embryo to help the blastocyst emerge prior to implantation. Formerly carried out by judicious use of an enzyme to dissolve the zona (but risking damage to the embryo), leading IVF programs use a microlaser.

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

The 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.

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

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

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 fertilisation up to the stage of egg retrieval.

A biopsy, or removal of one or two cells, from an early IVF embryo for preimplantation genetic diagnosis after in vitro fertilisation.

(ET) Procedure by which the embryo is placed in the uterus or into the fallopian tube after in vitro fertilisation.

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.

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 GnRH-antagonist made by Organon. The first to be FDA approved for women undergoing in vitro fertilisation), with good results when started on day 7 of the cycle, after 5 or 6 days FSH in suppressing the LH surge; the dosage, however, appears to be critical, to avoid over-suppressing natural luteinising hormone. Marketed as Antagon in the US and as Orgalutran elsewhere.

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.

(hPG) A mixture of follicle stimulating hormone (FSH) and luteinising hormone (LH) extracted directly from pituitary glands obtained at autopsies; not used in Australia or elsewhere since 1986, when it was shown that Creutzfeldt-Jakob disease (CJD), a deadly form of dementia, had been transmitted from its use, presumably due to contaminating and infected brain tissue. Before 1986 it had been used mostly for ovulation induction in women with amenorrhea (absent periods) for which other hormones or drugs had not been effective, although sporadic instances of its use for in vitro fertilisation are known in Australia. No new cases of CJD have been reported among former users of hPG since the early 1990s.

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 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.

Latin for 'in glass', meaning 'in the laboratory'. (In actual fact, these days, it's usually 'in plastic'!) See also in vitro fertilisation.

Maturation in the laboratory of the egg (as a primary oocyte) obtained from an immature tertiary follicle until it becomes a secondary oocyte competent to be fertilised by sperm using in vitro fertilisation. The smaller the follicle, the lower the proportion of eggs that mature successfully. ICSI can be used to increase the proportion of eggs that will fertilise, but the embryos on average do no better, and so no advantage is conferred by ICSI in this situation.

Early experience with superovulation for in vitro fertilisation, particularly at the original US program in Norfolk VA, saw women patients classified into three classes of responders, depending on how many eggs were obtained at egg retrieval. Poorer than usual outcomes could occur with either a low response or a high response (the high responders generally have polycystic ovaries, with a risk of ovarian hyperstimulation syndrome (OHSS). Many maneuvers have been used to try and retrieve more eggs among low responders, such as starting high dose FSH on day 1, the adding of growth hormone, the avoidance of GnRH-agonists etc., all generally without improving the results. Day 3 serum FSH levels can be high in low responders, indicating a depletion of eggs in the ovaries.

Oral anti-diabetic drug that improves many aspects of the polycystic ovary syndrome, including lowering of androgens, serum LH, insulin levels and weight, in combination with a low calorie diet; improves development of ovarian follicles and ovulation, as well as responsiveness to clomiphene or gonadotropins if ovulation induction or in vitro fertilisation is necessary.

(MESA) Using microsurgery to dissect the epididymis or rete testis (or sometimes the tubules of the testis itself -- see also testicular sperm extraction) to find motile sperm cells suitable to be aspirated, isolated and prepared for an in vitro fertilisation procedure, usually involving sperm microinjection, especially intracytoplasmic sperm insertion.

Azoospermia caused by low sperm production rates in the testis, including maturation arrest. Can often be overcome with testicular sperm extraction (TESE) followed by in vitro fertilisation utilising intracytoplasmic sperm insertion (ICSI).

The use of drugs to stimulate the development of follicles in the ovaries to undergo ovulation, such as clomiphene, various preparations containing follicle stimulating hormone (FSH), and human chorionic gonadotropin (hCG). The two main situations for it are: in the treatment of infertility due to anovulation typically when there is oligomenorrhea or amenorrhea; and for superovulation in assisted conception (e.g. in vitro fertilisation and gamete intrafallopian transfer)

fertilisation of an egg (a secondary oocyte) by more than one sperm (spermatozoon). In in vitro fertilisation, 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. Another name for it is polyspermic fertilisation.

(PROST) A form of assisted conception in which in vitro fertilisation (IVF) is used to produce fertilisation of one or more recovered eggs (oocytes). Useful if the potential fertilising ability of sperm (spermatozoa) is in doubt. Transfer is made on the day after egg retrieval and IVF, before the fertilised 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).

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 fertilisation.

Replication of a diploid organism after combination of haploid male and female gametes, each of which has been produced through the process of meiosis, thus assuring a reassortment of the alleles present among the two parents, in the form of a new, unique, individual genome. Preserved with in vitro fertilisation despite the absence of sexual intercourse. The opposite to cloning.

(TESE) Dissection into the testis itself, in men with azoospermia due to maturation arrest, to recover (by 'teasing out') immature sperm cells from the (often small) fraction of testicular tubules there which still contain such cells. The sperm cells are used for in vitro fertilisation using intracytoplasmic sperm insertion (ICSI).

(TEST) A variation of zygote intrafallopian transfer (ZIFT) in which, usually a day after when ZIFT (or PROST) would be carried out, cleaving embryos (at a two-cell to four-cell stage) are transferred to the fallopian tube as part of an in vitro fertilisation program.

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.

(ZIFT) A form of assisted conception in which in vitro fertilisation (IVF) is used to produce fertilisation; transfer is made on the day after egg retrieval and IVF, before the fertilised egg divides (it's at the zygote, or pronuclear stage). Useful if the potential fertilising ability of sperm is in doubt. 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 by transvaginal ultrasound (without anesthesia). Synonymous with pronuclear-stage transfer (PROST).