[helmchenlord]

Both genders let themselves get lulled into "I still have time, nowadays it's different" WAY too much. They're not just completely ignoring the normal decline of fertility ratios with age just because they see some other people getting their first children in their 30s or even 40s. They're also ignoring fertility ratios declining even stronger due to environmental factors.

Just because so many people are successfully postponing children doesn't mean it gets any easier after the age of 30 or your children are going to be as healthy as others. Statistically the probability of chromosome defects roughly increases by one factor for every year parents are older than 25. ~7 times higher at 35, 15 times at 40.

If you are generally open to having children, the best time is in your mid-20s. You still have much more options, support and energy and your children will be healthier. By the time you're out of the education system and your career takes off, your children are already in school and mostly taken care of. That also makes you much more attractive to employers. Nobody likes a 30-something who's been a reliable employee for the last years and might even be up for a promotion to a higher role, but now suddenly has kids and will be tired and unreliable for the next ten years.