Eating right early might reduce premature births. (Biomedicine).

A new study of sheep suggests that malnutrition around the time of conception may promote early delivery of offspring.

In the April 25 Science, Frank H. Bloomfield of the University of Auckland in New Zealand and his colleagues followed the pregnancies of 8 ewes that were consistently well fed and 10 ewes that were undernourished from 60 days before conception to 30 days after. Sheep in the latter group, whose weights fell to about 15 percent below normal, had an average pregnancy of 139 days, while the well-fed ewes were pregnant an average of 146 days.

The investigators found that modest undernutrition altered a crucial surge of the hormone cortisol that normally occurs in a mammalian fetus as birth approaches. This surge triggers maturation of organ systems and also seems to provide a signal to the mother that it's time to give birth. In half of the undernourished ewes, this cortisol spike came early.

"If these findings are applicable to human pregnancy, then a focus on events around the time of conception may hold the key to prevention of one of the major causes of preterm birth, Bloomfield and his colleagues conclude.--J.T.