Intrauterine growth retard (IUGR) continues to be a significant perinatology problem at the end of this century. The nature of the etiologic agent, the time when the attack occurred during pregnancy and its duration affect the type of IUGR.

Objective:

To study the evolution of fetal pancreas and placenta between the 18th and 2 1st day of pregnancy in rats submitted to maternal protein-calorie restriction.

Design:

Randomized controlled trial on laboratory animal.

Sample:

Forty-one normoglycemic pregnant Wistar rats.

Intervention:

Rats were divided into six experimental groups according to their access to food and date of cesarean section (18th or 21 st day): control with free access to food; diet restricted to 25 per cent introduced on 1 st day of pregnancy; and diet restricted to 25 per cent after the 3rd day of pregnancy.

Main measurements:

Newborn weight, placenta weight, histopathological study (morphological histochemistry).

Results:

Maternal protein-calorie malnutrition caused intrauterine growth retard (IUGR) after the 18 th day of pregnancy. Dietary restriction did not interfere with the morphology of the fetal pancreas and theimmunohistochemical study of the placenta showed that glycogen stores were decreased between the 18 th and 21 st day in the control group and in a diet restricted to 25 per cent from the first day of pregnancy. Dietary restriction after the 3rd day of pregnancy led to low placental glycogen concentrations on the 18 th day and disappearance on the 21 st day.

Conclusion:

The pathophysiology of IUGR due to maternal protein-calorie restriction in rats is related to lower placental weight and low placental glycogen stores.