The first step of treating infertility in many cases is to treat the underlying cause of infertility. For example, in cases where thyroid disease causes hormone imbalances, medication for thyroid disease may be able to restore fertility.
The first Dark Lord of the Sith was Ajunta Pall, a fallen Jedi and leader of the Dark Exiles. Ajunta Pall was a former Jedi Master following the First Great Schism who was very much into the teachings of alchemy. He eventually discovered the way to create and shape life, something his successors would attempt to learn themselves for eons.
In 19 BBY, Bane's dream was realized, and his Rule of Two validated, when the Sith finally achieved control over the galaxy and wiped out the Jedi Order. Darth Bane was the legendary Sith'ari, an individual who had been prophesied to restore the Sith to glory.