RESUMEN
We mimicked the condition of severe maternal diabetes by administering high doses of streptozotocin (STZ) to the pregnant rat to determine the effects of increased glucose availability on fetal glucose transport and to assess whether a relationship might exist between glucose transport and altered fetal growth. Fetuses of STZ-treated pregnant rats were growth retarded (3.86 +/- 0.13 vs. 5.29 +/- 0.06 g), hyperglycemic (30.0 +/- 1.0 vs. 5.5 +/- 0.5 mM/liter), and hyperinsulinemic (1263.8 +/- 138.3 vs. 817.9 +/- 116.7 pM/liter). Glucose uptake, Glut 1 messenger RNA (mRNA), and Glut 1 protein were greater in STZ-treated fetal brain than in controls (50%, 83%, and 50%, respectively; P < 0.05). Glut 3 mRNA levels in STZ-treated and control fetal brain were equivalent and significantly less than levels of Glut 1. Glucose uptake in muscle of STZ fetuses was 70% greater than control values (P < 0.05). Glut 1 mRNA levels were increased by 93% in STZ fetal muscle (P < 0.05). Neither Glut 3 nor Glut 4 mRNA could be detected in STZ-treated and control fetal muscle. Glut 1 protein levels were increased by 70% in STZ-treated fetal muscle compared to control muscle (P < 0.05). These observations indicate that altered glucose transport per se does not directly contribute to fetal growth retardation with maternal STZ diabetes. Perturbations in other physiological and metabolic factors may contribute to the pathogenesis of fetal growth retardation in STZ-induced diabetes during pregnancy.
Asunto(s)
Diabetes Mellitus Experimental/metabolismo , Feto/metabolismo , Glucosa/metabolismo , Embarazo en Diabéticas , Animales , Transporte Biológico , Encéfalo/embriología , Desoxiglucosa/farmacocinética , Desarrollo Embrionario y Fetal , Femenino , Feto/fisiología , Transportador de Glucosa de Tipo 1 , Proteínas de Transporte de Monosacáridos/genética , Músculos/embriología , Embarazo , ARN Mensajero/metabolismo , RatasRESUMEN
OBJECTIVE: Our purpose was to determine the incidence of significant neonatal morbidity in fetuses with documented pulmonary maturity delivered before 37 weeks' gestation. STUDY DESIGN: A retrospective review of 213 pregnancies with documented fetal lung maturity (lecithin/sphingomyelin ratio > or = 2.0 or phosphatidylglycerol present) and delivery before 37 weeks was performed. The incidence of neonatal respiratory distress syndrome, bronchopulmonary dysplasia, grade 3 or 4 intraventricular hemorrhage, necrotizing enterocolitis, patent ductus arteriosus, retinopathy of prematurity, infectious morbidity, hyperbilirubinemia, and admission to the special care nursery was determined for those pregnancies with intact membranes and preterm premature rupture of membranes. RESULTS: Serious neonatal morbidity declined with advancing gestational age and was less common after 32 completed weeks of pregnancy. Although the frequencies of respiratory distress syndrome, grade 3 or 4 intraventricular hemorrhage, and necrotizing enterocolitis were 19.4% (12/62), 8.1% (5/62), and 4.8% (3/62), respectively, at < or = 33 weeks' gestation, one case of respiratory distress syndrome, one case of grade 3 intraventricular hemorrhage, and one case of necrotizing enterocolitis occurred in the 151 neonates born at > or = 34 weeks' gestation. CONCLUSIONS: In spite of fetal lung maturity major neonatal morbidity was observed in our patient population. These data relating neonatal morbidity to gestational age are useful in the critical decision regarding timing of delivery.