The soul of a man in the next reincarnation will always be male and a female soul will always be female because male and female souls are two opposite, complementary huge blocks that cannot develop one without the other. They cannot just change because in essence they are completely different.
The female soul develops in its desires and supplies them for implementation to the male soul. The male soul must realize these desires in a way of receiving the force that corrects them both, from above, from the next degree, and as a result of their correct interaction with the help of this third force it gives offspring—the next degree.
Therefore, there is a man, a woman, and a Creator here who, together with them, participates in the conception and birth of the next common degree.
From KabTV’s “Close-up. Reincarnation” 5/3/10