Recurrence of gestational diabetes mellitus: identification of risk factors.

The objective of this paper is to evaluate the influence of maternal and neonatal factors on the recurrence of gestational diabetes mellitus (GDM). A study was conducted on 164 predominantly Hispanic patients whose index pregnancy was complicated by GDM and whose subsequent consecutive pregnancy was managed at our institution between January 1988 and December 1992. The diagnosis of GDM was based on the criteria recommended by the National Diabetes Data Group using a 100-g oral glucose tolerance test.

Pulsatile oxytocin administered to ewes at 120 to 140 days gestational age increases the rate of maturation of the fetal electrocorticogram and nuchal activity.

Spontaneous, long lasting epochs of myometrial contractility, contractures, occur throughout the majority of pregnancy in sheep. Contractures are temporally related to a switch in fetal electroencephalogram (ECoG) patterns from low to high voltage. In late gestation, fetal ECoG increases in voltage.

Oxytocin given in a pulsatile manner to the ewe at 120 to 140 days' gestational age increases fetal sheep plasma cortisol.

A single intravenous injection of oxytocin into pregnant sheep (123 to 144 days' gestational age) causes a bout of myometrial activity and an increase in fetal plasma corticotropin levels. We hypothesized that a sustained increased frequency of myometrial contractures accelerates the normal increase in fetal adrenal secretion in sheep in the last 3 weeks of gestation. To test this hypothesis, pulses of saline solution (group 1, 9 ewes and 10 fetuses) or oxytocin (group 2, 11 ewes and 12 fetuses) 600 or 960 microU/kg/min for 5 of every 30 minutes were infused into the maternal jugular vein for 6 days beginning at day 128 +/- 2 (mean +/- SD) days' gestational age.

Zinc supplementation during pregnancy: effects on selected blood constituents and on progress and outcome of pregnancy in low-income women of Mexican descent.

The effects of zinc supplementation on levels of various blood constituents and the outcome of pregnancy in 213 Hispanic women attending a prenatal clinic in Los Angeles was assessed in this double-blind study. The women were randomized into either a control (C) or a zinc-supplemented (Z) group and received similar vitamin and mineral supplements except that 20 mg zinc was added to the Z group's capsules. At the final interview, women (C + Z) with low serum Zn levels (less than or equal to 53 micrograms/dl) had higher (p less than 0.

Androstenedione, testosterone, and estradiol concentrations in fetal and maternal plasma in late pregnancy in the sheep.

Fetal and maternal plasma concentrations of androstenedione, testosterone, and estradiol were measured in chronically catheterized pregnant sheep during late gestation, spontaneous term delivery, and premature delivery induced by the infusion of low doses of synthetic ACTH-(1-24) (ACTH) to the fetus at 120-130 days gestation. RIAs employing two different antisera directed at different sites of each molecule were used in combination with Celite column chromatography to ensure the specificity of the hormone measurements. Fetal plasma concentrations of all three hormones were greater than the respective maternal concentration at all periods investigated, except immediately before ACTH-induced delivery when fetal testosterone and estradiol concentrations were lower.

Effect of abolition of fetal movement on fetal intravascular PO2 and incidence of tonic myometrial contractures in the pregnant ewe at 114 to 134 days' gestation.

The possibility that fetal movements play a role in the initiation of the bursts of tonic myometrial activity (contractures) that occur throughout the second half of pregnancy in the sheep has been examined by the administration of the curare derivative pancuronium to abolish fetal movement. The duration and frequency of the electromyographic bursts associated with contractures, as well as the increase in intrauterine pressure generated by the contractures, were unchanged. However, within 1 hour of the abolition of fetal movement, fetal jugular venous PO2 was significantly elevated and remained elevated for at least 6 hours.

Erythrocyte enzymes in sheep: comparison of activity in fetal, newborn, maternal and nonpregnant ewe erythrocytes.

Hematological data and the activities of 21 red cell enzymes were measured in 8 nonpregnant ewes, 13 chronically catheterized fetuses at 125-135 days of gestation, and 8 of their mothers. In addition, 7 lambs were followed from birth to 17 days of age. Fetal sheep red cells have dramatically increased activities for 17 of 21 enzymes measured compared with adult nonpregnant ewes.

Midazolam and diazepam: maternal and fetal effects in the pregnant ewe.

Maternal and fetal hemodynamic effects and placental transfer of midazolam (RO 21-3981, Hoffman-LaRoche) and diazepam were studied in chronically instrumented pregnant ewes. Diazepam administration resulted in greater increases of maternal and fetal heart rates and maternal blood pressure, and greater alteration of total uterine blood flow than did administration of comparable doses of midazolam. Neither drug altered fetal mean arterial pressure or maternal and fetal respiratory gases.

Vascular reactivity to angiotensin II in the normotensive and hypertensive pregnant ewe.

The circulatory responses to progressively increasing doses of angiotensin II were studied in the same group of chronically instrumented unanesthetized pregnant sheep during three consecutive periods: a) normotensive with intact kidneys; b) normotensive with unilateral nephrectomy; and c) one-kidney hypertension. The results show that 1) the pressor response to a given dose of angiotensin was significantly greater in the normotensive than in the hypertensive condition; 2) uterine blood flow decreased markedly with the development of hypertension; 3) uterine circulatory response to angiotensin depended on the dosage; the response was less the the hypertensive than in the normotensive condition; 4) renal blood flow decreased and renal vascular resistance increased during angiotensin infusion, but the response was less in the hypertensive than in the normotensive condition; the response of the renal circulation decreased with increasing doses of angiotensin. These observations suggest a generalized vascular refractoriness to exogenous angiotensin II in the pregnant ewe with experimental renal hypertension.

Effect of dopamine on hypotension induced by spinal anesthesia.

Chronically instrumented, near-term pregnant sheep were subjected to autonomic blockade with spinal anesthesia. Systemic arterial pressure, heart rate, and uterine blood flow decreased and uterine vascular resistance increased during the spinal blockade. Infusion of dopamine during the spinal hypotension corrected the disturbed circulatory parameters.