This is going to get me laughed at, I know it. But I have to ask...

Are the members of the Adepta Sororitas as sterile as their Space Marine counterparts? (and say this loosely BTW)

A friend of mine is starting up an army with mixed units, SoB, Inquisition, and select units from Imp Guard. Now, I enjoy the fluff and backstory that comes with 40K but when he asked me if the SoB's breed, I really didn't have an answer for him. I searched a few codices and researched on the Lexicanum, and still I have no idea.

Can anybody help me with this psuedo-bizarre yet perfectly acceptable question?