If he doesn't have a bald spot he could be fixed already www.glidernursery.com/breeding.html
"Sugar gliders have an estrus (heat) cycle every 29 days. Females can begin going through estrus as early as 4 months old, or 16 weeks out of pouch (OOP). A female is pregnant for 16 days, after which point the immature joey migrates to the pouch where it will stay and nurse for approximately 70 days. Once the joey fully emerges, or comes OOP, this is considered their birth date. Joeys should remain with their parents until they are 10 weeks OOP."
Inbreeding is a big worry too (exp. their are only two lines for platinums)
Some times they reject the baby or worse
Females need special care more protein vitamin