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.
Darth Bane, born under the name of Dessel, was the Sith'ari and the Dark Lord of the Sith responsible for creating the Rule of Two. Born in 1026 BBY, he was raised as a poor miner on the Outer Rim planet Apatros.