My wife’s theory is that there will be a lot of babies born in about 6 months (9 months after the quarantine started), but only for first time parents. Being quarantined with a child is the absolute best birth control.
Sure there will be a load of unplanned pregnancies, but a lot of people actively planning their family might choose to wait to see if they have a job/a place to live/are still alive after the pandemic is over.
Apparently there was a similar drop in birth-rate after the 2008 financial crash - people just held back waiting to see what happened before committing to having kids.