Maternal regulation of fetal growth.

The birth weight of the mothers, sibs, maternal aunts and their children were compared with those of 400 full-term, appropriate-for-gestational age, 181 true premature, 200 small-for-gestational age, and 261 correlation was found between the weight of the newborns and their mothers and maternal relatives in each case. The findings support the Ounsted theory that the rate of fetal growth is influenced by a familial component with maternal transmission. This regulation does not operate in true prematurity where the effect of environmental and pathological factors seems to prevail over the familial and genetic features.