Relation between infants' birth weight and mothers' mortality: prospective observational study

Smith, Harding, and Rosato do not mention the most likely explanation
for the strong negative association between fetal growth and maternal
cardiovascular disease. This is the cardiovascular feat that is inherent
in carrying a normal pregnancy. Investigators have found that the
difference between cardiac performance between trained athletes and couch
potatoes disappear during pregnancy: the latter increase their end
diastolic volume, stroke volume and cardiac output maxima to equal the
former.

A normal pregnancy is the equivalent, in cardiac output and
ventilatory volume, of a 10,000 km walk.

The maximum perfusion to the normal uterus increases by 1000 to 1500
percent over about six months, challenging any impairment of the vascular
system. It is well know that hypertensives and diabetics with vascular
disease are prone to having small babies.

It is apparent that the outcome of this stress test in infant birth
weight is a more sensitive test of this system than other measures
available to the authors.

My only question is does this apply to "gestational diabetics", whose
sugars we try to control carefully. If we were more relaxed about this
would they then live longer?

James S. SMeltzer, MD