Change of sex is effected before it’s manifestation by vedic rites properly performed because the actions performed with excellence of place and time certainly produce desired results otherwise not.
Hence considering the woman as pregnant she should be administered pumsavana (measures which help procreate a male progeny) before the fetus is manifested. After taking two undamaged leaf-buds from the easterly and northerly branches of a banyan tree grown in a common place and putting them in curd alongwith two excellent black gram or white mustard seeds, it should be given to the woman to drink in pusya star.
Similarly, the paste of jivaka, rsabhaka, apamarga and saireyaka– collectively or individually as required, added with milk; or putting a kudyakitaka (a type of insect) or matsayka (a small fish) in a handful of water should be given to drink in pusya star.
Small and fire-colored man-shaped pieces of gold, silver or iron put in curd, milk or handful of water should be taken wholly in pusya star. In the pusya star itself, she should inhale the steam coming from the preparation of sali rice while being cooked. She should also use a drop with a cotton swab in the right nostril of the liquid made of the flour mixed with water and put on the threshold. Whatever useful measure for pumsavana is suggested by Brahmanas or reliable ladies, that should also be applied. Thus the measures for pumsavana are said.
[CHARAKA SAMHITA CHAPTER-8 SLOKA-19]