Even if true, your "leading cause of death" statement is meaningless as young women are not generally going to die from any other cause. If you "solve" teenage pregnancy, it might well become swallowing food without chewing.

I bet pregnancy is not the "leading cause of death" among 80yo women. That must be the best age to start having children.

Anyways, I couldn't find the reference to your statement by following the link but I found that risk of pre–eclampsia(only clearly stated risk to the mother) and lower birth weight is higher than in 20–24 —no mention of other age ranges.

The report mentions that adolescent childbirth is correlated with low socio–economic status and education. Did they control for that when doing the risk assessment? It is not clear.

No mention of genetic risk to the offspring. No mention of the lives of the offspring that were "terminated" in the making of the non–pregnancy statistics.

Just some vague "abuse" statements that do not include figures for abuse of non–female young people.

WHO, indeed.