Infertility is believed to be due to the lack of which vitamin?

The full form of $GIFT$ is

The latest technique to produce a child is $GIFT$. The full form is

Test tube baby means a baby born when:

The amniotic fluid is taken out with the help of a surgical needle,and the separation of the embryo cells present in this fluid is done by:

The procedure of $GIFT$ involves the transfer of a female gamete into the fallopian tube. Can gametes be transferred to the uterus to achieve the same result? Explain.