14? 18? 22?
Young is subjective. In some cultures, it is common to have a child by the age of 16 and in others it's not acceptable to have one until you're over the age of 30. It depends on maturity, current living situation, money, overall health, the man and woman's current focuses, etc.
Our lives in this part of the world turned out to be very difficult to manage and afford, so we usually put off weddings and children for our thirties or even forties. Most of the cases in which young couples have children is because they did not plan it. They just screwed it up.
Although there are few cases of planned babies in young couples, they tend to come from impoverished neighborhoods and poor educational background, which means they decided without any basis or foundation. They just did it because this is what they were taught to do despite the difficulties they should face when bringing a baby to this fvcking world.
Teenage pregnancy and childbirth is not something that should be encouraged and/or glorified. Often, teens who become pregnant and decide to carry their pregnancy to term cripple their chances for going on to some type of education and training to learn a skill, and to therefore have meaningful employment. All too often, pregnant teens end up on public assistance because it's their only option, plus most teens who end up pregnant don't come from backgrounds where an interest in any kind of education thrives. Plus most of them aren't interested in school and drop out.
Another reason that teens should not have children is because they're not physically, mentally or emotionally mature themselves, and they stand an even better chance of having a baby that's born prematurely, and/or has severe developmental delays, or other neurological problems.