Fertility basics
Fertilisation is the union of a mature egg (oocyte) and a sperm to form a single-celled embryo (zygote), which then begins dividing over the following days. It normally occurs in the fallopian tube after natural intercourse, or in the laboratory during IVF or ICSI. Successful fertilisation is the first checkpoint after egg retrieval in an IVF cycle, but fertilisation alone does not guarantee that an embryo will develop normally, reach the blastocyst stage or implant.
Also known as: egg meets sperm, fertilization
Related India guides
Sources
- Indian Council of Medical Research (icmr.gov.in)
- ICMR Standard Treatment Workflows (icmr.gov.in/standard-treatment-workflows-stws)
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.