In-Vitro Fertilisation (IVF) is just one of several assisted conception techniques available to help people with fertility problems to have a baby. It involves an egg being surgically removed from the ovary and fertilised outside the body. The main IVF technique was developed in the 1970s. This involves giving the woman fertility drugs to stimulate egg production, and then surgically retrieving the eggs from the ovaries. She is then given hormones to prepare her uterus for pregnancy, while the eggs are fertilised with the sperm in a laboratory. The embryos are then implanted into the woman's uterus, and if all goes well, a normal pregnancy is achieved. There are several risks involved with assisted conception. The diagnostic and treatment procedures can involve discomfort, particularly for the woman undergoing IVF, who may experience side effects from the fertility drugs, and may find the egg retrieval uncomfortable. Ovarian hyper-stimulation syndrome (OHSS) is a rare but known side effect of IVF. It occurs when the fertility drugs given to stimulate egg production in the woman are so successful that the ovaries cannot cope with the increased number of eggs. A mild incidence can cause pain and bloating. If the overstimulation is severe, blood clots, kidney damage and twisting of the ovaries may occur, and monitoring in hospital will be required. OHSS can jeopardise the progress of the treatment cycle. Some assisted conception techniques carry an increased risk of ectopic pregnancy, where the fertilised egg implants in the fallopian tubes instead of the uterus. There is an increased chance of multiple gestation, that is, of producing twins or triplets, as the chances of IVF success are maximised by more than one embryo being put back into the womb. This has associated dangers, such as an increased risk of problems occurring during the pregnancy or labour, and of the babies being delivered prematurely. IVF procedures developed more recently include Intra-cytoplasmic Sperm Injection (ICSI). This helps those men for whom the standard IVF technique would fail, for example if their sperm are unable to penetrate the egg, to achieve pregnancy with their partner. nhs.gov.uk feb2008