In vitro fertilisation (IVF): surgeon removing eggs from a woman's ovaries using a trans-vaginal probe. The ultrasound image (background, left) is used to guide the probe through the cervix and uterus and along the fallopian tubes towards the ovaries. The woman will have been given fertility drugs to stimulate the production of several ova, rather than the usual one. The collected eggs will be fertilised in a petri dish, using a fresh or frozen sample of the husband's sperm. The embryos will then be transferred back into the uterus via a catheter inserted through the cervix. 3-4 embryos are often introduced to increase the probability that one will implant.