Plain-English fertility definitions

IVF and fertility glossary

79 terms used in Australian fertility care, grouped by theme. Definitions are cross-checked against RANZCOG patient information, NHMRC ART guidelines, MBS Online and the ANZARD Annual Report. Updated 2026.

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General information only

These definitions are general consumer information, not medical advice. Speak with your fertility specialist about how any of these terms apply to your specific situation.

Glossary section

Diagnostics

15 terms

AFC: Antral Follicle Count. Ultrasound count of small (2 – 10 mm) follicles in both ovaries on day 2 or 3 of the cycle. Combined with AMH to predict stimulation response.
AMH: Anti-Müllerian Hormone. A blood test marker of ovarian reserve. Produced by small antral follicles; falls steadily with age. Used to predict response to ovarian stimulation and to counsel on egg-freezing yield. AMH does not predict natural fertility on its own.
DNA fragmentation index (DFI): Sperm DNA-damage test. Elevated DFI is associated with poorer fertilisation and higher miscarriage. Treatment options include lifestyle, antioxidants and surgical retrieval in selected cases.
FSH: Follicle-Stimulating Hormone. Pituitary hormone driving follicular growth. Day-3 FSH is a historic ovarian-reserve test; AMH is now preferred because it is less cycle-dependent.
HSG: Hysterosalpingogram. X-ray of the uterus and fallopian tubes with iodine contrast. Tests for tubal patency. Mildly fertility-enhancing for several cycles after the test.
HyCoSy / SonoHSG: Saline-and-air ultrasound version of the HSG. Lower-cost, no radiation, similar sensitivity for tubal patency.
hysteroscopy: Endoscopic inspection of the uterine cavity. Diagnostic and operative – removes polyps, septum and adhesions.
karyotype: Blood test that maps the 46 chromosomes. Used to look for balanced translocations after recurrent miscarriage or repeat IVF failure.
laparoscopy: Keyhole abdominal surgery. Used to diagnose and treat endometriosis, tubal disease and adhesions where indicated.
LH: Luteinising Hormone. Pituitary hormone whose mid-cycle surge triggers ovulation. Used in ovulation prediction kits.
oestradiol (E2): The principal oestrogen during the follicular phase. Rises with follicular growth across stimulation; used to titrate FSH dose and predict trigger timing.
progesterone: Hormone produced by the corpus luteum (and by exogenous support post-transfer) that maintains the endometrium. Pre-trigger rise can signal premature luteinisation.
prolactin: Pituitary hormone elevated in some forms of anovulation. Routinely measured during fertility work-up; high levels treated with cabergoline.
semen analysis (WHO 6th): Standard male-factor test against WHO 6th edition reference ranges (2021): volume, concentration, total count, motility, morphology, vitality. Two samples recommended several weeks apart.
TSH: Thyroid-Stimulating Hormone. Sub-clinical hypothyroidism is treated to TSH below 2.5 mIU/L before fertility treatment in most clinics.

Glossary section

Cycle structure

12 terms

antagonist protocol: Common short-stimulation protocol. FSH from day 2; GnRH antagonist (Cetrotide, Orgalutran) introduced once the lead follicle reaches about 14 mm to prevent premature LH surge. Trigger when ready. Lower OHSS risk than long agonist.
beta-hCG: Quantitative blood test measuring human Chorionic Gonadotropin. The diagnostic pregnancy test post-transfer. Rising serial betas suggest a viable pregnancy.
ET / embryo transfer: Transcervical placement of one (rarely two) embryos in the uterine cavity under ultrasound guidance. Painless; no anaesthetic. Five days after retrieval (fresh) or in a separate later cycle (FET).
FET: Frozen Embryo Transfer. Transfer of a previously cryopreserved embryo in a later cycle. Either natural-cycle (timed to ovulation) or hormone-supported.
freeze-all: Strategy of vitrifying all viable embryos and deferring transfer to a later FET cycle. Used to avoid OHSS, to allow PGT analysis or to optimise endometrium.
IVM: In Vitro Maturation. Eggs retrieved at an immature stage and matured in the lab. Niche use in PCOS or where avoiding hormonal stimulation is required.
long agonist (long-down-regulation): Older protocol that suppresses the pituitary with Synarel (nafarelin) from the previous luteal phase. Used in some endometriosis, adenomyosis and high-AMH cases. Higher OHSS risk.
luteal support: Progesterone (vaginal, oral or injectable) and sometimes oestrogen given after transfer to support the endometrium until placental progesterone takes over.
mild stimulation: Lower-dose FSH protocol aiming for 5 – 8 eggs rather than 12+. Used in poor responders, low-AMH patients and patients wanting fewer injections. Lower per-cycle yield but similar per-egg quality.
OPU / egg retrieval: Ovum Pick-Up. Transvaginal ultrasound-guided needle aspiration of follicles under sedation in a day-procedure unit. 15 – 30 minutes. Recovery the same day.
trigger shot: Final injection that matures the eggs ahead of retrieval. Either hCG (Ovidrel, Pregnyl) or a GnRH agonist (Lucrin) in antagonist cycles. Retrieval 36 hours later.
two-week wait: Patient-coined term for the period between embryo transfer and the pregnancy blood test. Clinically the beta-hCG is drawn 9 – 14 days post-transfer.

Glossary section

Embryology

14 terms

aneuploid embryo: Embryo with an abnormal chromosome count. Most aneuploid embryos do not implant or end in early miscarriage.
blastocyst: Day 5 – 6 embryo with an inner cell mass and trophectoderm separated by a fluid-filled cavity. Transfer-stage in most clinics.
cleavage stage: Day 2 – 3 embryos with 2 – 8 cells. Some clinics transfer at cleavage; most extend to blastocyst when embryo numbers allow.
cryopreservation: Storage of eggs, sperm or embryos at –196°C in liquid nitrogen. Storage fees typically $400 – $700 per year in Australia.
embryo grading: Morphological grading of embryos (Gardner grading at blastocyst stage: expansion + ICM + TE). Predicts implantation probability but is not perfect.
euploid embryo: Embryo with a normal chromosome count for transfer-stage analysis (typically 46 chromosomes).
fertilisation: Combination of sperm and egg to form a zygote. Standard IVF or ICSI. Checked the morning after retrieval.
hatching: Embryo emerging from the zona pellucida prior to implantation. Assisted hatching (laser thinning of the zona) is a clinic-specific add-on.
ICSI: Intracytoplasmic Sperm Injection. A single sperm injected into each mature egg using a micromanipulator. Indicated for male factor or prior fertilisation failure.
morula: Day 4 embryo with compacted cells, prior to blastocyst formation.
mosaic embryo: PGT-A result where some cells are euploid and some are aneuploid. International guidance (PGDIS, ASRM) supports transfer of selected mosaic embryos after counselling; success rates intermediate between euploid and aneuploid.
PICSI / IMSI: Sperm-selection variants. PICSI selects sperm bound to hyaluronic acid; IMSI uses high-magnification morphology selection. Limited evidence base.
time-lapse incubation: Continuous-imaging incubator (e.g. EmbryoScope, Geri+) that records embryo development without removing the dish. Clinic-specific add-on.
vitrification: Ultra-rapid freezing technique that prevents ice-crystal damage. Industry standard for eggs and embryos. Replaced slow-freeze in the late 2000s.

Glossary section

Genetic testing

5 terms

carrier screening: Couple screening for autosomal recessive carrier status (e.g. Mackenzie’s Mission expanded panel). Done before treatment in many clinics.
NIPT: Non-Invasive Prenatal Testing. Post-pregnancy cell-free fetal DNA test from 10 weeks. Screens for the common aneuploidies. Separate from PGT.
PGT-A: Pre-implantation Genetic Testing for Aneuploidy. Tests 5 – 10 trophectoderm cells from a blastocyst for chromosomal copy number. Reduces miscarriage and time-to-live-birth, particularly in advanced maternal age. About $600 per embryo plus a base fee.
PGT-M: Pre-implantation Genetic Testing for Monogenic disorders. Tests for a specific single-gene condition (e.g. cystic fibrosis, fragile X, BRCA). Bespoke probe per family; longer set-up.
PGT-SR: Pre-implantation Genetic Testing for Structural Rearrangements. Tests for chromosome translocations and inversions where one parent is a known carrier.

Glossary section

Donor + surrogacy

7 terms

altruistic donation: Donation without payment beyond reimbursement of reasonable expenses. The only legal form of donation in Australia.
altruistic surrogacy: A surrogate carries a pregnancy for intended parents without payment beyond reasonable expenses. Legal in every Australian state under state-specific Acts.
commercial surrogacy: Surrogacy involving payment to the surrogate beyond expenses. Illegal in every Australian state. Extra-territorial offence for residents of NSW, QLD and the ACT (illegal overseas too).
donor compensation (Australia): Donors may be reimbursed for reasonable medical, travel and lost-wages expenses. Paid donation is illegal in every Australian state.
donor-conceived register: State or clinic register holding identifying information about donors and their donor-conceived offspring. Children have a right to access identifying donor information at 18 (younger with parental consent in some states).
implications counselling: Compulsory pre-conception counselling by a specialist fertility counsellor for donors, surrogates and intended parents. Required under NHMRC ART guidelines.
Parentage Order: State-court order transferring legal parentage from the surrogate (and her spouse) to the intended parents after birth. Timing window varies by state (28 days to 6 months typically).

Glossary section

Risks

4 terms

ectopic pregnancy: Pregnancy implanting outside the uterine cavity (typically a fallopian tube). Slightly more common after IVF (around 2 – 4%) than in spontaneous conception.
miscarriage: Loss of pregnancy before 20 weeks. Rate increases sharply with maternal age. PGT-A reduces (but does not eliminate) miscarriage risk in older patients.
multiple pregnancy: Twin or higher-order pregnancy. Single-embryo transfer is now standard practice in Australia, reducing twin rates to under 5%.
OHSS: Ovarian Hyper-Stimulation Syndrome. Over-response to fertility drugs causing enlarged ovaries, ascites and (rarely) thromboembolism. Reduced sharply by GnRH-agonist trigger and freeze-all. Severe OHSS is uncommon (<1%) with modern protocols.

Glossary section

Funding

6 terms

bulk-billed IVF: Cycle billed entirely to Medicare with minimal or no out-of-pocket. Australian providers include Adora Fertility (Virtus) and Connect IVF.
EMSN: Extended Medicare Safety Net. Once annual out-of-hospital gap fees pass the threshold (~$811 in 2026), Medicare reimburses 80% of subsequent gap fees for the rest of the calendar year.
informed financial consent: Clinic document setting out the planned items, fees, expected Medicare rebates and out-of-pocket. Should be signed before any procedure.
MBS: Medicare Benefits Schedule. The federal schedule of items and rebates. IVF items include specialist consultation, monitoring ultrasound, egg retrieval, embryo transfer and FET. See mbsonline.gov.au.
PBS: Pharmaceutical Benefits Scheme. IVF medications including FSH, GnRH agonists and antagonists, and progesterone support are PBS-listed under Authority items.
PBS Safety Net: 2026 thresholds: $277.20 (concessional) and $1,694 (general). After the threshold scripts are concessional or free for the rest of the calendar year.

Glossary section

Regulatory

8 terms

AHPRA: Australian Health Practitioner Regulation Agency. National registration body for medical practitioners. All Australian fertility specialists are registered with AHPRA.
ANZARD: Australia and New Zealand Assisted Reproduction Database. The authoritative source for national IVF outcomes, run by the National Perinatal Epidemiology and Statistics Unit at UNSW. Publishes annual reports.
CREI: Certificate in Reproductive Endocrinology and Infertility. The sub-specialty credential held by Australian fertility specialists.
NHMRC ART Guidelines: Ethical Guidelines on the Use of Assisted Reproductive Technology in Clinical Practice and Research. Set the framework for donor cycles, sibling limits and counselling requirements.
Patient Review Panel (VIC): Victorian statutory body that reviews surrogacy arrangements and some donor cycles before treatment can proceed.
RANZCOG: Royal Australian and New Zealand College of Obstetricians and Gynaecologists. Sets clinical standards relevant to fertility specialists; fertility sub-specialty training (CREI) sits under it.
RTAC: Reproductive Technology Accreditation Committee. Federal accreditation body for Australian ART units. Accreditation is a prerequisite to claim Medicare for ART services.
VARTA: Victorian Assisted Reproductive Treatment Authority. Victorian regulator covering donor-register access, surrogacy reviews and information services.

Glossary section

Anatomy

4 terms

corpus luteum: Hormone-producing structure that forms in the follicle after ovulation. Produces progesterone to support the early pregnancy.
endometrium: The uterine lining. Thickens across the cycle in response to oestrogen and progesterone. Receptivity matters at embryo transfer.
follicle: Fluid-filled ovarian structure containing an oocyte (egg). Multiple follicles develop with FSH stimulation.
oocyte: The medical term for an egg, particularly during retrieval and laboratory handling.

Glossary section

Outcomes

4 terms

cumulative live birth: Probability of at least one live birth across multiple cycles. The most patient-meaningful number.
implantation rate: Embryos implanting (visible gestational sac) divided by embryos transferred. A useful lab + uterine signal.
per-cycle-started live birth: Live birth count divided by cycles initiated. ANZARD’s primary outcome metric.
per-transfer live birth: Live birth count divided by embryo transfers. Used in SART (US) reporting. Always looks higher than per-cycle-started because cancelled cycles are excluded.

Related guides

Use the glossary alongside

Outcomes

IVF success rates by age →

ART types

IUI, IVF, ICSI, FET →

Funding

Medicare rebates for IVF →