During in vitro fertilisation (IVF) or intra-cytoplasmic sperm injection (ICSI) treatment, fertility drugs are used to stimulate the ovaries to produce more eggs than usual.
These are then fertilised with your partner’s, or a donor’s sperm to create embryos.
Because there is normally a number of unused embryos, some people choose to freeze the good quality unused embryos for use in later treatment cycles or for donation.
More top news
Some patchy mist and fog overnight as the temperature's dip.
The actor joined hundreds of mourners at the funeral of the 30-year-old make up artist in the village of Cappawhite, Ireland.
Odense zoo plans to publicly dissect a year-old lion - undeterred by outrage at giraffe who was killed in Copenhagen last year.