Wow... I just heard something shocking about women being 40 years old

A 40-year-old woman in Korean age
If she wants to meet someone through matchmaking rather than natural dating,
she only gets matched with divorcees or single people in their mid-to-late 40s.
They say the reason is because of pregnancy.
These days, medical technology allows for successful IVF
even for those in their mid-40s.
What could the real reason be?