Biologically, Nietzcheans reproduce in the exact same way as Earth humans do. There are no additional biological drives (like a Vulcan), nor do they need 3 other partners to be able to reproduce (like Andorians). One male and one female is all it takes to reproduce and create a Nietzchean child.
Nietzchean enter puberty anywhere from 10-14 years, with an average
of 11.8 years of age.
To a Nietzchean, reproduction is the single-most important event in their lives. They choose their mates with care, only reproducing with those who have genes that will strengthen the clan, the Pride, and the Nietzchean species as a whole.
To become married and reproduce, a Nietzchean must present their potential mate to their clan's (or pride's) Matriarch, who will do a genetic scan and determine if the genes of the potential mate are strong. If approved, the couple becomes married in a private ceremony, involving only the two of them. The male and female exchange bracers that signify that they are one. Nietzscheans are very, very choosy about their mates. The point is not just to get people pregnant. It's to make sure your children reach breeding age themselves. Love 'em and leave 'em is a valid reproductive strategy, but it's risky. You can win big, but you can lose big too. And in Nietzschean society, women definitely have full control of their reproductive options. Which means they chose the men, not the other way around.
A Nietzchean will only reproduce with another Nietzchean, except in the most dire of circumstances (one example could be that a male Nietzchean who is about to die would procreate with a "normal" human, to carry on his genes). A Nietzchean would NEVER reproduce with a member of any other species except for "normal" humans. They would feel that the Nietzchean species would become contaminated with unpure genetic material. Nietzchean/Human hybrids do exist, but in very small numbers. They are noticible by their shorter than average arm spikes, and also for the fact that are are smaller in size then the average Nietzchean, even though they are still larger in size than their "normal" parent.
It is normal for a Nietzchean male to have many wives, and have children with each, with some families as large as One male with 10+ wives, and 30+ children.