Invitro fertilization or ivf is done in patients of bilateral tubal block, male infertility where there is severely reduced sperm count or motility, pcos where all other treatment has failed, severe endometriosis, unexplained infertility where all modalities of treatment have failed. In severe male factor infertility, icsi or intra cytoplasmic sperm injection is resorted to. The success rate of ivf ranges from 35 to 40 percent.