I perceive teen parenthood as risky. Teen parents, well, it depends on the parent.
There is very strong evidence that under 20s are the highest risk of pregnancy- and childbirth-related complications & death and for long-term health problems (even when separating out 15-19 year olds from those younger who are obviously at even higher risk), only getting close to that again in the mid-40s, and increased risk of health issues in children. It's also within the time period where young adults of either sex are at higher risk of experiencing mental distress and mental illnesses, and the pressures and stress of pregnancy and children can contribute to that. Pregnancy and childbirth are also common spark points for partners to turn abusive or further abusive, and the social isolation that is very common in active young parents makes that harder to get out of. There are some benefits if all goes well with mother and child to being younger when their own children are less reliant & so can do more then, but that can still happen at the safer age from 24.
I had my first at 19, foolish having had a friend die in late pregnancy a couple years before, but I was 19 & thought my pregnancy being wanted in a marriage and supported would make it totally different & I was worried about the stories of early menopause that I would soon have the choice made for me (story goes that my great-grandmother was done with menopause at 25 & my grandmother struggled with fertility from her early twenties).
I was also convinced, as the survivor of child abuse, that I would be totally different to my family. It was not so simple. I had to accept my limitations hard and fast, I had to accept that no matter what I wanted, maternalness doesn't come naturally to me, I had no experience of it and no one to ask & C-PTSD really gets in the way parenting as well as I'd like sometimes. I fit the isolated teen mum to a T and continued that way for many years. We all have to balance the risks and benefits of our choices with what life gives us - teen development makes that hard & having horrible parents makes that exponetially harder.
I thankfully had few issues in pregnancy or childbirth the first time around, but I started having more health problems soon after & my spouse's health deteriorated sharply in multiple ways. Within 2 years, I went from high school athlete to using mobility aides and he ended up having to take a year off and have surgery. We both improved and had more children. We took a risk, and it bit us in the butt, if not as much as others so we didn't really think about it. It would be years later that the association was made at least for us.
I've come to accept our choice and have said before that it was the best path with what we knew and was available to us at the time. We took a risk, paid a toll for it and still do, but have benefitted in that our children met the few relatives we like before they died and eventually met some great people due to them being their ages. If I could have a magic chance to have all that and delay for 5 years, I think we would all have benefited. I'd mostly likely at least have been a calmer parent with more time to build a support network for those early years. It's true that our current health problems may have happened without that, but early parenthood certainly didn't help and is a known contributing factor. At the least, I could have focused on his and my health more earlier rather than chasing toddlers & excusing it as 'all parents are tired and sore'. I still view myself a lucky disabled parent, I like my life even with being burnt by our risky choices, but as much as I liked having been well done with the toddler stage before 30 & my kids as they are now (most of the time - my teens don't seem to think my younger age makes me any more able to understand than any other adult), I wouldn't recommend what I did to my own children or others & worry about teens who will get far more burnt than I did.