Hourly fetal urine production rate in the fasting and the postprandial state of normal and diabetic pregnant women.

Abstract

To examine whether maternal meal ingestion affects fetal urine production in normal and diabetic pregnancies and whether fetal urine production is increased in diabetic pregnancy. The hourly fetal urine production rate was measured before and after breakfast in 17 fetuses of diabetic mothers and 14 of women with normal glucose tolerance. The rate was calculated by taking serial measurements of fetal bladder volume at 2-3-minute intervals by ultrasonography. In the control group, the hourly fetal urine production rate was significantly greater during the 2 hours after breakfast than that in the fasting state (P < .0005). In the diabetic group, the rate also tended to increase after breakfast (P = .07). In the postprandial state, the hourly fetal urine production rate was not significantly different between the groups. However, in the fasting state, it was significantly greater in the diabetic group than in the control group (P < .03). Maternal meal ingestion should increase fetal urine production. The increased fetal urine production in the fasting state in diabetics is assumed to be one cause of hydramnios.