Glucose Production in Pregnant Women at Term Gestation

Abstract

A B S T R A C T The effects of pregnancy and diabetes on systemic glucose production rates and the sources of glucose for the human fetus in utero were evaluated in five normal, four gestationally diabetic, and one insulin-dependent diabetic subject undergoing elective caesarean section at term gestation. Five normal nonpregnant women were studied for comparison. Systemic glucose production rates were measured with stable tracer [1-13C]glucose according to the primeconstant rate infusion technique. Even though the plasma glucose concentration during normal pregnancy had declined as compared with the nonpregnant subjects (P < 0.0005), the systemic glucose production rate was 16% greater, a rate sufficient to provide the glucose requirement of the fetus at term gestation. The decline in glucose concentration could be the result of an increase in apparent volume of distribution of glucose. Systemic glucose production rates in wellcontrolled, gestationally diabetic subjects were similar to those in normal pregnant subjects (2.07±0.53 vs. 2.42±0.51 mg/kg-min). The sources of glucose for the human fetus at term gestation were evaluated by comparing (a) natural variation in 13C:12C ratio of plasma glucose and (b) enriched '3C:'2C ratio ofplasma glucose during [1-13C]glucose infusion in maternal and fetal blood at delivery in both normal and diabetic subjects. These data showed that the fetal glucose pool was in equilibrium with the maternal glucose pool in both normal and diabetic subjects, indicating that a brief A preliminary report of this work has been published as an abstract: Pediatr. Res. 1977.

Pathophysiology of postprandial hyperglycaemia in women with type 1 diabetes during pregnancy

“…Fasting plasma glucose concentrations were notably lower (3.6-4.2 mmol/l) compared with women with type 1 diabetes (6.1 mmol/l). Another study by the same investigators comprising ten pregnant women (five healthy, four with gestational diabetes and one with type 1 diabetes) at term suggested no differences in EGP between healthy controls and women with gestational diabetes [3]. These studies focused on gluconeogenesis during fasting conditions and did not evaluate postprandial glucose control.…”

“…Women with type 1 diabetes spend on average 8 h per day in hyperglycaemia in late gestation, with most hyperglycaemic excursions following meals [2]. As the maternal and fetal glucose pools are in equilibrium [3], with a rapid transfer of glucose to the fetus according to maternal glucose concentration [4], maternal hyperglycaemia is associated with an adverse pregnancy outcome, most commonly fetal growth acceleration and increased risk of large-for-gestational-age offspring [5][6][7]. This remains the most common complication of pregnancy in type 1 diabetes [8][9][10] and confers immediate risks of delivery complications and neonatal hypoglycaemia in addition to the longer-term risks of insulin resistance, obesity and type 2 diabetes [11][12][13].…”

Influence of the nutritional deficit of foetal survival and growth and plasma metabolites in rabbit does

“…A decrease in preprandial glucose concentration throughout pregnancy has been observed in the rabbit and in other species (Leturque et al, 1986(Leturque et al, , 1987KOhl, 1991 and could be explained either by an increase in the rate of utilization or in the distribution space as observed in other species (man: Kalhan et al, 1979;rat: Leturque et al, 1981 (1984). In the rabbit, the last days of pregnancy correspond to the phase of maximal growth of the foetuses (Hudson and Hull, 1975), whereas the appetite of the doe decreases.…”

The Effects of Glucocorticoids on Fetal and Placental Development

“…Efficient placental (maternal to fetal) transport of glucose is crucial to sustain the normal development and survival of the fetus in utero because its own glucose production is minimal [142]. The factors regulating transplacental glucose transfer are largely unknown.…”