Vitro Fertilization - Human Development
In case a woman cannot conceive due to her uterine tubes are blocked she can become pregnant by means of in vitro fertilization. In this procedure, oocytes are removed from the women's ovary and mixed along with sperm cells in a laboratory dish for fertilization. After checking that development has started one or more morulas are returned to the uterus of the women for implantation and succeeding development. To increase the chances of success, the woman is generally treated with fertility drugs (clomiphene and gonadotropins). Growth of follicles is monitored through ultra sonography and when follicles have reached a fixed size she is given HCG to induce ovulation. Oocytes released from the ovary are collected with laproscope and incubated at 37°C in a buffered medium with pH 7.4 and when they are mature, they are mixed with sperms which have been washed to remove inhibitory factors. Fertilized eggs are after that incubated in a special culture medium and normal embryos at 8-16 cell stage are transferred to the uterus by the cervix. The woman is then treated along with progesterone to promote a favorable uterine environment for implantation. Successful implantation occurs in 20% to 30% of the cases.