Setting aside the setting specific aspect, and avoiding any moral positions ... Biology says modern people with 100 year life times can have children from age 10+ to age 60+ ... Very roughly half their life span.hiro said:How would increased longevity affect reproduction?
Will medical technology enable safe and reliable birth control?
Would people have the choice of surrogate mothers or alternate means of child bearing?
What percentage would choose natural childbirth or surrogates?
How old will a woman still be able to conceive? Will longevity treatments postpone menopause?
These are setting specific questions, please don't make this about current day issues.
For a people that live 200 years, a 100 year window of childbearing would seem a lower limit on future biology.
The question then becomes, what are the cultural norms and expectations.
Crowded conditions bring pressures to simply replace your numbers (zero growth).
On the other hand, a cultural view that "we have only a small population and a giant world to develop" (supporting ever higher TLs) might create a culture where having a baby every 5 years until you reach about 10 children might be the norm.
If you had 100,000 people on a new colony and wanted to reach a population of about a billion as quickly as possible (to support a starfaring infrastructure and allow you to expand to the surrounding worlds waiting to be developed), the society might want to look to cloning and artificial wombs to expand the rate of reproduction.
It seems more a matter of culture than biology.