Postponing marriage due to health issues

Islam tells us to marry when a boy or girl becomes mature, age 12-13. But according to science, if a girl marries at 12-13 and becomes pregnant then she has to face problems like losing the new born baby, decrease in her growth of height, sugar problems, high BP, etc .

So in these cases, can we delay the marriage till the girl or boy is 19 years?

In previous days, in the 18th century and before that, did it also happen that they used to marry young and these problems had taken place (decrease in height, high BP, high sugar, risk of death, etc.).