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Understanding fertility language

Have you ever found yourself confused by all the abbreviations we use here at FA? Don't worry, we've got you covered!

Below are the most common terms you may come across
  • Clomiphene & Letrozole A pill usually taken for 5 days early in the menstrual cycle that increases the number of follicles that grow in the ovary. Commonly used in Ovulation Induction.
  • Ovulation Induction 'OI' is a treatment to induce ovulation in women with irregular or absent cycles.
  • Intra-Uterine-Insemination 'IUI' is when sperm is placed directly into the uterus
  • In Vitro Fertilisation 'IVF' It strictly means adding sperm and egg together outside the body, but it is usually used to describe the whole process covering medications, egg collection, fertilisation, and embryo transfer.
  • Intra-Cytoplasmic Sperm Injection - 'ICSI' - Surely one of the craziest bits of IVF jargon – it simply means a single sperm is injected into each egg when the sperm cannot do this job themselves.
  • Intra-cytoplasmic Morphologically selected Sperm Injection - 'IMSI' An even worse bit of jargon describing ultra-high magnification of sperm before they are selected for ICSI.
  • In Vitro Maturation - 'IVM' is a variation of IVF that starts with immature eggs collected without using ovarian stimulation.
  • Donor Sperm - 'DS' (formerly called Donor Insemination). Donor sperm can be used with IUI and IVF.
  • Donor Oocyte or donor eggDO - ‘oocyte’ is the scientific name for an egg. Donor egg is when another woman’s egg is used in an IVF cycle.
  • Donor embryo 'DE' - is when an embryo is donated to someone who is not the biological parent.

Language used during an IVF Cycle

  • Cycle - One course of treatment. With IVF, this is from Day 1 through to the pregnancy test.
  • OPU - Oocyte PickUp – also known as egg collection, when the eggs are taken from the ovaries.
  • ET - Embryo Transfer – when the embryo(s) is transferred back into the uterus. SET Single Embryo Transfer – when only one embryo is transferred into the uterus at a time.
  • FET & TER - Frozen Embryo Transfer. Essentially the defrosting and replacement of an embryo that has been frozen and stored with us after a cycle of ivf . Also known as Thawed Embryo Replacement (TER).
  • Manufactured cycle - An artificial menstrual cycle used to provide the right environment for the transfer of embryos.
  • Blastocyst - The name given to an embryo 5-6 days after fertilisation when it consists of an outer layer of cells that will become the placenta and an inner mass of cells that will become the baby.
  • SSR - Surgical Sperm Retrieval – when sperm are taken directly from the testes using a fine needle.
  • PESA - Percutaneous Epididymal Sperm Aspiration – SSR when sperm are taken from the epididymis, which is a tiny organ sitting on top of the testis.
  • TESA - Testicular Sperm Aspiration, Testicular Sperm Extraction – other names for SSR.
  • OHSS - Ovarian Hyper-Stimulation Syndrome – a condition that can occur a few days after egg collection that is caused by too many follicles being stimulated to grow at once in the ovaries. Fluid moves from the blood into the abdomen and into tissue. Untreated, it can have serious consequences.
  • PGD - Pre Implantation Genetic Diagnosis, which is testing embryos for a genetic condition.
  • PGS - Pre Implantation Genetic Screening, which is testing embryos to see if they have the correct number of chromosomes.
  • TiMI - Timelapse Morphometry Imaging, for studying embryo development.
  • Day 1 - The first day of your period or menstrual bleeding. When you start a treatment
    cycle, we count day 1 as the first day you wake with your period. So if your period starts in the afternoon, the next day is called day 1.
  • Catheter - This is a fine tube put into the body. In fertility it nearly always refers to a catheter put into the uterus for embryo transfer in IVF or insemination in IUI.
  • Biochemical pregnancy - A pregnancy that ends at a very early stage. Its name comes from the fact that the pregnancy is detected by biochemical tests like blood tests.
  • Clinical pregnancy - A pregnancy that can be detected by an ultrasound scan.

Other terminology you may come across

  • Abdomen/abdominal - The area of the tummy

  • Acrosome - The membrane covering the head of the sperm containing the enzymes that are released to enable the sperm to enter the egg.

  • Amniocentesis - Procedure where cells are taken from the fluid around the foetus to detect abnormalities, usually between the 15th and 17th weeks of pregnancy

  • Amniotic membrane - Inner membrane around the amniotic fluid containing a foetus

  • Anencephaly - Severe neural tube defect in which there is no brain development

  • Anovulation - Lack of ovulation

  • Azoospermia - Absence of sperm in the semen

  • Basal body temperature - Ovulation leads to increased blood progesterone levels which are associated with a small rise in body temperature.

  • Body Mass Index (BMI) - Measure of body mass determined by dividing a person's weight (in kilograms) by height (in metres) squared. Normal values are between 20 and 25.

  • Capacitation - The final phase of development in the sperm in which it acquires the ability to fertilise an egg

  • Cervix - The lower narrow end of the uterus that connects the uterine cavity to the vagina.

  • Chlamydia - Infection that may damage the reproductive system.

  • Chorionic membrane - The outer layer of the membranes that surround the foetal sac

  • Chorionic Villus Sampling (CVS) - A procedure where cells are taken from the placenta around 11 weeks of pregnancy to test for abnormalities in the foetus.

  • Cilia - Hair-like projections that line some tubes, e.g., the Fallopian tubes

  • Chromosome - Structures in the cell nucleus that contain our hereditary material in the form of DNA

  • Corpus luteum - A yellow structure in the ovary formed after the rupture of the egg from that site. It produces progesterone.

  • Conjoined twins - Twins that are joined by some parts of their bodies.

  • Cryptorchidism - Undescended testes

  • Dilatation and curettage (D&C) - Operation to scrape out the lining of the uterus.

  • Ectopic pregnancy - Pregnancy outside the uterus, commonly in the Fallopian tube.

  • Ejaculate - The discharge of semen from the penis during male orgasm

  • Endometriosis - The presence of endometrial cells at sites outside the lining of the uterus

  • Endometrium - Lining of the uterus

  • Epididymis - A coiled tube 3-5 m in length attached to the back of the testis. It stores sperm and gives rise to their motility.

  • Fallopian tube - Tube that runs from the uterus out towards the ovary. It is responsible for the passage of sperm, eggs and embryos.

  • Fecundity - The probability of a live birth from one cycle of ovulation

  • Fibroid - Benign muscular growth in the uterus

  • Fimbria - Delicate, finger-like fringes that collect the egg

  • Follicle - A fluid-filled sac in the ovary in which the egg matures

  • Follicular phase - The phase of the menstrual cycle in which the dominant follicle grows to reach maturity. The follicular phase is completed at the time of egg release (ovulation)

  • Gestation - Length of pregnancy

  • Granulosa cells - Cells that surround each egg and line each follicle and are responsible for feeding the egg with nutrients and producing oestrogen

  • Human chorionic gonadotrophin (hCG) - Hormone that is produced by the developing placenta

  • Insemination - Placing sperm into the cervix or uterus, or in IVF placing sperm with the eggs in culture conditions the laboratory

  • Karyotpye - A test looking at the number and appearance of chromosomes from cells

  • Laparoscopy - Technique in which a telescope visualises the structures within the abdomen. Commonly used to check tubal patency and the presence of any pelvic pathology

  • LMP - Last menstrual period

  • Luteal phase - The phase of the menstrual cycle from ovulation to the start of the next period

  • Luteinising hormone (LH) - One of the hormones produced by the pituitary gland in the brain. A rapid rise of LH initiates the onset of ovulation

  • Menarche - Onset of menstruation

  • Menstruation period - The lining of the uterus is shed in response to falling oestrogen and progesterone levels at the end of the luteal phase

  • Oestrogen - A hormone produced by the ovaries

  • Ovarian stimulation - Stimulating the ovary to produce more than one mature egg in a menstrual cycle by giving fertility drugs

  • Ovary - The female gonad that contains the eggs

  • Ovulation - Release of the egg from the ovary. This usually occurs about 14 days before the next menstrual period

  • Ovum - The egg

  • Pelvic inflammatory disease - Infection of the tubes and uterus that can lead to infertility by adhesion formation

  • Peri menopause - The five to 10 years prior to cessation of periods (menopause)

  • Phyto oestrogens - Oestrogens in plants

  • Pituitary gland - Pituitary gland A small gland at the base of the brain. It produces FSH, LH and other hormones

  • Placenta - The organ that transfers nutrients and oxygen from the mother to the baby

  • Progesterone - Hormone produced by the corpus luteum. It prepares the uterus for implantation of a developing embryo if fertilisation has occurred

  • Pronuclei - Once an egg has been fertilised, two pronuclei may be seen, one from the egg and one from the sperm

  • Puberty - The time in adolescence in which sexual organs mature and secondary sexual characteristics appear

  • Scrotum -The pouch that contains the testicles

  • Semen - Fluid that constitutes the ejaculate

  • Semen analysis - The microscopic examination of semen to determine the number of sperm (sperm count) their shapes (morphology) and their ability to move (motility)

  • Seminal fluid - The liquid part of the semen in which sperm swim around

  • Siamese twins - Conjoined twins

  • Spermatogenesis & Spermatogonia - Sperm production & The cells within the testis that differentiate into sperm

  • Sperm - The male reproductive cell that unites with the egg (ovum) to produce an embryo

  • Spina bifida - A developmental abnormality in which the bones of the spinal column do not fuse

  • Testes - The male gonads responsible for production of sperm and testosterone

  • Ultrasound - High frequency sound waves that may be used to identify bodily structures

  • Uterus - The organ in the female in which the foetus develops. Often called the womb

  • Zona pellucida - Outer covering or ”shell' of the egg

Vagina - The canal in the female that leads to the cervix, which leads to the uterus.

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The Biological Clock

This tool indicates:

  • Natural conception per month if you have no fertility issues
  • IVF success rate at the same age
  • When to seek help after months of unsuccessful attempts

If you are concerned at any stage – we recommend booking a doctor appointment or a free nurse consultation. The sooner you make a plan the better your chances in the long term.

When to seek advice early

  • If you have polycystic ovaries, endometriosis, or have been through a cancer diagnosis; we recommend you get in touch quickly so we can talk you through all your options and give you the greatest possible chance of success.
  • If you’re a single woman considering motherhood in the future; it’s best to approach us early and consider egg freezing as this can be an option for you while you have a higher ovarian reserve and healthier eggs.
Set your age and the months you’ve been trying to conceive
Your chance of having a baby per month for fertile couples
Your chance of having a baby per IVF cycle (if experiencing infertility)

Body Mass Index calculator

Being overweight or underweight can reduce fertility, so it is important to keep your body weight within the normal healthy range.

Body Mass Index (BMI) is an indication of your body weight and can be calculated by dividing weight by height. You should aim for a BMI of between 20 and 25, as this will optimise your chances of conception.

Woman’s BMI below 19

Even in these modern times, nature knows best. If a woman's BMI falls below 19, the body senses famine and ovulation is switched off to prevent the risk of having a baby with malnutrition. Excessive exercise can reduce body fat and increase muscle mass to a point where periods cease for the same reason. Risk of miscarriage is also increased in women with a low BMI.

Being underweight

If a woman's BMI falls below 19, the body senses famine and ovulation is switched off to prevent the risk of having a baby with malnutrition. Excessive exercise can reduce body fat and increase muscle mass to a point where periods cease for the same reason. Risk of miscarriage is also increased in women with a low BMI.

BMI’s greater than 30

This can reduce fertility by 50%. Pregnancy for women with a 30+ BMI is often associated with problems such as maternal diabetes, high blood pressure, big babies and increased risk of caesarean section.

Add your height and weight to calculate your BMI