Damage from sex?

The claim that sex is harmful no matter what, and horribly and uniquely harmful at that, is plainly absurd. It is not always harmful for adults, and it does not miraculously stop being harmful at 18th birthday.

However, remember that the costs of sex are real and big.

Making and raising babies is, and ought to be, one of the most expensive things a man ought to do in her or his lifetime. It can be hugely profitable - in terms of not merely the physical pleasure of making babies (and nursing them) but in the real payoff, which is having offspring who succeed in breeding in their own turn. Plus possible financial payoffs in lifetime, like being the beloved wife of a wealthy husband, and beloved mother of successful and wealthy children.

Yet if mishandled, it can be a great loss to the adult or child. There might be no payoff at all - for example both the baby and mother may die as a complication of being pregnant while too young, or as a complication of being pregnant while too old. Or the baby and/or mother may die as a consequence of poverty and lack of support from father - whether due to his unwillingness or inability to support. Or the child/ren may grow up to be poor and unsuccessful in breeding in their turn. Or the child may die or otherwise fail to breed due to illnesses inherited from its father....

Even if the payoff is there, it might be not worth the investment - she or he might have done better having picked a better partner, and delayed sex.

When should a girl be able to decide to make a baby? And, for comparison, when should the girl be able to decide to borrow large sums of money to invest in starting a business?