I find that incongruous to what I see, 15-18 year old girls every where with kids in tow.
Also, as far as rank in the world, socialist governmenst love to pad their stats to make them look like a panacea.
But the average age for first childbirth is also going up-up-up in all the developed countries, so I really don't know how relevant this is for comparison's sake.
The question of reporting is also hard to figure. Computerized statistic-gathering has definitely made the reporting of maternal morbidity and mortality to rise, but that also would be true of other developed countries, not just the USA.