In certain women oviducts are blocked. Such women cannot bear babies because sperms are not able to reach the egg for fertilisation. For such parents, the medical science has developed a technique calledin vitro fertilisation or IVF (fertilisation outside the body) In this method, a freshly released egg and sperms are collected and kept together for a few hours. If fertilisation of the egg by the sperm is successful, the zygote is allowed to develop for about a week. The developed zygote is then placed in the mother 's uterus. The further development of zygote and the embryo takes place in the uterus of the mother. The baby is born at the appropriate time like other babies. The babies born through the IVF are called test tube babies, (although the term is misleading).