No. A few years ago, I looked at a study that said if you want three kids with >90% probability, you should marry at 23. For two kids, the age is 26-28 I think. This is the woman's age. Fertility decline rapidly after 30. Plus there's infertility between kids if you choose to breastfeed, etc. There's also a lot of other factors to consider that could delay having kids (miscarriages, difficulty conceiving, etc). Of course the father's age also matters but I don't have data on that.
Yeah, but in general it's not enough to impact having 2 kids. If getting pregnant for the first time at 30, you could wait the recommended 18 months between kids and still have two without it being a geriatric pregnancy. You don't need to start at 18 to have 2 kids.
That's not how pregnancy works. It can take quite a while to get pregnant. it's a bell curve. Certainly, a lot of couples will have another, but if you want to have another with a good chance of success (>90%), you have to start younger.
