Age, obesity, environment, diet, lifestyle, medical factors and others play a big role in infertility issue. In vitro fertilization (IVF) is a process by which an egg is fertilised by sperm outside the body : in vitro. The process involves monitoring and stimulating a woman's ovulatory process, removing ovum or ova (egg or eggs) from the woman's ovaries and letting sperm fertilise them in a liquid in a laboratory. The fertilised egg is cultured for 2–6 days in a growth medium and is then implanted in the same or another woman's uterus, with the intention of establishing a successful pregnancy.