Everything worth having in life involves some risk - you could have a heart attack or a stroke the next minute, your wife/husband could cheat on you/leave you, the company you work for could implode and go bankrupt, and so on.
What about the risk of forever regretting that you didn't even try? Everyone has to decide for themselves what level of risk they are ok with (I'm not going to do base jumping, for instance :D), but if you want a "safe" life, you have to stay indoors, live like a hermit, and forego all human contact ;)
The point is don't let "I can still have a baby at 40" persuade anyone to delay it beyond their 20s if they have any choice or control over the matter.
There's still a lot of risks, particularly of disappointment, but also massively elevated risk of gestational diabetes and Down syndrome.