Conjugal visits. Reproduce before going to prison. Reproduce after prison. Reproduce while on parole.
I have a cousin in Los Angeles with three kids (last I heard about a decade ago) and he's in and out of prison all the time. I'm just having my first. Idiocracy wasn't too off the mark.
One particular strength of male humans is their long reproductive years. There are many cases of 80 and 90 year old men reproducing.
ttps://www.prisonpolicy.org/scans/bjs/vospats.pdf
> Based on admissions data for 1992 to 1994, violent State prisoners had an average sentence of about 10 years and were expected to serve slightly less than 5 years on average.
That's nearly zero impact on a man's reproductive life.