Infertility primarily refers to the biological inability of a person to contribute to conception (fertilisation). Infertility may also refer to the state of a woman who is unable to carry a pregnancy to full term. About 40% of the problems of infertility are due to female. Ovulation is the process of releasing egg from the ovary and if that egg is fertilized by a sperm then only pregnancy will start. Under ideal circumstances, the probability that a woman will get pregnant during a single menstrual cycle is only about 30% and when conception does occur, only 50 - 60% of pregnancies advance beyond the 20th week.