In my parents' generation, there was a lot of pressure to have children before 30. There was a widespread belief that giving birth after 30 risked the health of the mother and the child. As medicine advanced and neonatal care greatly improved, that deadline was pushed back and women started to seriously entertain the idea of careers before having children.

There are other cultural and societal factors at play, but the greater longevity and better medical care have opened up the time period for the expectations that previous generations had for their 20s.

From a 42 y.o. with 34 y.o. spouse who are undergoing IVF: the drop-off of fertility after 35 is still very real.

There may be future interventions that correct for that, but generally, quality of ova starts declining after 30 and much more so after 35.

It’s also not just about giving birth, but a woman’s body is probably far better at recovery after birth in their 20s than 30s.

Not to mention the energy to keep up with little ones, and if you ever want the option of more than 2 kids. And of course if you’re 30+ when you have kids, and your kids are 30+ when they have kids, you are pushing 65 to 70+ which makes playing with the grandkids not as much fun and you’re soon to be less of an asset in terms of help and possibly a liability for your kids due to declining health.

On the other hand, you may have increased your chances at having a higher paying career, but I suspect, for many, the extra savings don’t quite make up for the trade offs.

I can tell you that you’re way more prepared to be a parent a decade later. Bodies be damned.

Also a good point, trade offs all around to consider!

I had mine in 30 to 35 range, but if I could go back in time and had found my spouse, I think I would have opted to have them in 25 to 30 range. However, no one in my social circles has kids in their 20s and barely anyone is married by 30 so we also may have been socially isolated if we had chosen to do that.

But I try to think back to what I did in my 25 to 30 range that I thought was worth delaying starting a family and I can’t come up with anything, other than being a little bit further ahead in the rat race. But all the other rats are thinking the same thing, so who is really benefiting?

So it would seem the trend is very much to settle and stabilize in your 30's. I do hope we figure out even better and safer ways to allow women to give birth a little later, if they so choose.

It also seems useful to become a parent with that extra decade of life experience. And if we incentivize exercise in the later years, it could offset the "feeling tired at 70" thing? My fiancé's grandpa runs marathons and honestly has more energy than I do!

Most of what we do in our 20s doesn’t seem that important after the fact (unless you’re an Olympic athlete or otherwise very lucky) but I think it’s an important part of growing up and feeling secure — in yourself, your career, and your relationship. All three types of security are very important to being a good parent.

You can't have kids when you are in your 20s if you are a man who cannot find a woman willing to date you who also wants to have kids while you are in your 20s.

The bottleneck is the same as it is for any issue regarding children.

The prospective mother must be willing.

This is interesting because I'm 25 and sometimes worry that I'm going to miss out on the opportunity to start a solid family. It feels so difficult to find anyone my age who wants more than just a fling, and women in their 30s don't even bother with someone my age or they already have kids. From what you're saying, maybe I'm not going to miss out, I'm just thinking about it too soon.

Don’t sweat it too much. I feel like my life got a lot more stable in my 30s. I moved countries, met my now wife, bought a house together, had two kids and finally married. Even personally and career wise it’s been a period of stability and growth.

I also don’t think you’re thinking about things too soon. We’re all slightly different. Also don’t make decisions for other people by writing them off. Just because they present one way doesn’t make that the sum total of who they are. You’ll need to have relationships in order to meet someone to have kids with.

Most people would be married with families by their late 20s. Now many enter into a sort of second childhood and settle down in their 30s or beyond. Hell, I still have some acquaintances from school who are slowly transitioning into the creepy old guy hitting on 24 year olds.

I've always taken it to be about your peak - when life is at its best. In your 20s, you're generally in good health, maintain a good social network from school or college, active social life, etc. I'm in my early 40s and feel like I have it more together now than in the past: fewer but better friendships, more interesting conversations, more means to do what I want in terms of travel or entertainment.

My take on it is: At whatever age you are, you still feel like there's lots of time ahead of you, because people live longer/can do more/etc.