Embryology laboratory

How fertilisation is assessed: what embryologists look for

Understand the difference between collected eggs, mature eggs and normal fertilisation, including the pronuclear check and update timing.

IVF versus ICSI: how the laboratory chooses a method

Understand how sperm and eggs meet in conventional IVF and ICSI, when microinjection may be justified and what it cannot guarantee.

Embryo development days 1–6: a laboratory map

Follow a fertilised egg through pronuclei, cleavage, morula and blastocyst stages, while understanding the limits of each daily update.

Embryo grading: what the letters and numbers mean

Learn how cleavage-stage and blastocyst grades are assigned, why laboratories can differ and what a grade cannot promise.

Blastocyst culture: waiting until days five and six

Understand why embryos may be cultured to blastocyst, how it can support selection and the possibility that no embryo remains for transfer.

Time-lapse embryo monitoring: what the camera shows

Understand how images are taken inside an incubator, the value of stable culture and why a video or algorithm cannot guarantee an outcome.

Embryo vitrification: rapid freezing and secure storage

Understand how blastocysts are rapidly frozen, which embryos are selected and what consent, storage and future-use decisions involve.

Frozen embryo thaw survival: what does it mean?

Understand how a vitrified embryo is warmed, what laboratory survival means, how re-expansion is assessed and how the transfer plan can change.

Preimplantation genetic testing: types and limits

Understand PGT-A, PGT-M and PGT-SR, blastocyst biopsy, mosaic or inconclusive results and why prenatal testing may still be advised.

IVF laboratory safety: identity and quality systems

Understand how eggs, sperm and embryos remain linked to the right patient, and how witnessing, incubator monitoring and emergency plans reduce risk.