In my world, the overpopulation crisis doesn’t exist. The explanation is simple: Our women are genetically designed to endure only two pregnancies for the rest of their lives. It might be uncommon from where you come from, but this is how it has always been for us. To that effect, adoption is on the rise due to the number of miscarriages per year. What you would call “orphanage” in your world, we call it “Parental Lottery”. The only time the global population number climbs to the roof is when girls are born.