A cleavage-stage embryo is an early-stage embryo, typically assessed on Day 2 or Day 3 after egg collection, made up of a small number of cells called blastomeres. The embryology team records the number and appearance of these cells as one part of tracking how the embryo is developing. Cleavage-stage appearance describes what is seen at that time point in the laboratory; it does not, by itself, determine whether an embryo will go on to reach the blastocyst stage or result in a pregnancy. Embryos may be transferred at cleavage stage or cultured further, depending on clinical circumstances and laboratory practice.
Also known as: blastomere, Day-2 embryo, Day-3 embryo, Day 2 embryo, Day 3 embryo
Sources
- ICMR Standard Treatment Workflows (icmr.gov.in/standard-treatment-workflows-stws)
- European Society of Human Reproduction and Embryology (eshre.eu)
Last reviewed: 9 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.