DIET, EXERCISE, AND FETOPLACENTAL GROWTH

Background and Objective: Evidence from multiple sources indicates tha t maternal blood glucose levels correlate directly with size at birth and that both diet and exercise alter them. The purpose of these preli minary studies was to test the hypothesis that the carbohydrate mix in a pregnant woman's diet modifies the primary effect of exercise on fe te-placental growth through its effects on maternal blood glucose leve ls. Experimental Designs and Methods: A prospective randomized design was used to examine the effects of two isocaloric, high carbohydrate d iets combined with regular exercise on maternal blood glucose levels a nd various indices of morphometric outcome in healthy pregnant women ( n = 12). The diets differed only in the type of carbohydrate ingested. Those in one had low glycemic indices and those in the other had high glycemic indices. Results: During pregnancy, women on the low glycemi c carbohydrate diet experienced no significant change in their glycemi c response to mixed caloric intake while those who switched to the hig h glycemic carbohydrate diet experienced a 190 % increase in their res ponse. The later was associated with larger placental size, increased birth weight, and greater maternal weight gain. Conclusion: These prel iminary data indicate that the type of dietary carbohydrate in a physi cally active pregnant woman's diet influences her blood glucose profil e which alters placental growth, size at birth, and weight gain.