. However, where such corrections are not possible, the couples could be assisted to have children through certain special techniques commonly known as assisted reproductive technologies  $(ART)$.
          In vitro fertilisation ( $IVF-$ fertilisation outside the body in almost similar conditions as that in the body) followed by embryo transfer $(ET$) is one of such methods.

In this method, popularly known as test tube baby programme, ova from the wife/donor (female) and sperms from the husband/donor (male) are collected and are induced to form zygote under simulated conditions in the laboratory.

The zygote or early embryos (with upto $8$ blastomeres) could then be transferred into the fallopian tube ($ZIFT -$ zygote intra fallopian transfer) and embryos with more than $8$ blastomeres, into the uterus ($IUT -$ intra uterine transfer), to complete its further development. Embryos formed by in-vivo fertilisation (fusion of gametes within the female) also could be used for such transfer to assist those females who cannot conceive.
          Transfer of an ovum collected from a donor into the fallopian tube ( $GIFT -$ gamete intra fallopian transfer) of another female who cannot produce one, but can provide suitable environment for fertilisation and further development is another method attempted.

 Intra cytoplasmic sperm injection $(ICSI)$ is another specialised procedure to form an embryo in the laboratory in which a sperm is directly injected into the ovum

. Infertility cases either due to inability of the male partner to inseminate the female or due to very low sperm counts in the ejaculates, could be corrected by artificial insemination $(AI)$ technique. In this technique, the semen collected either from the husband or a healthy donor is artificially introduced either into the vagina or into the uterus ( $IUI -$ intra-uterine insemination) of the female.