Pregnancy outcome in insulin-dependent diabetes: temporal relationships with metabolic control during specific pregnancy periods

There are specific temporal relationships between metabolic control during different periods of pregnancy and outcome in insulin-dependent diabetic pregnancies. The rate of spontaneous abortions correlates with poor periconceptional glycemic control. Major malformations and decreased infant bone mineral content at birth correlate with poor first trimester glycemic control. Increased rates of preeclampsia and premature labor correlate with poor glycemic control in the second trimester. The development of macrosomia and that of neonatal hypoglycemia correlate with poor third trimester glycemic control. Perinatal asphyxia and neonatal hypoglycemia correlate with hyperglycemia in labor. We suggest that each stage of the pregnancy, if complicated by poor glycemic control, may lead to specific, temporally related complications. Glycemic control from the periconceptional period to the time of delivery appears important in order to minimize complications of the insulin-dependent diabetic pregnancy.

Periconceptional metabolic status and risk for spontaneous abortion in insulin-dependent diabetic pregnancies

The rate of clinically apparent spontaneous abortions in insulin-dependent diabetic pregnancies has been prospectively determined to be twice as frequent as for the general population (29.5% versus 10 to 15%). In a series of several successive studies, we have shown that spontaneous abortions are associated with poor metabolic control around conception and/or in the early weeks of pregnancy, but not in the 1 to 2 weeks preceding the abortive event itself. There is also a significant relationship between decreased maternal magnesium status (as assessed by maternal serum magnesium concentration) and adverse fetal outcome (spontaneous abortion and/or major congenital malformations) in insulin-dependent diabetic women. We speculate that improvement of glycemic control and of magnesium status before conception and in the very early phases of organogenesis might improve embryonic and fetal survival.

Amniotic fluid cholesteryl palmitate in pregnancies complicated by diabetes mellitus

Amniotic fluid cholesteryl palmitate, as measured by thin-layer chromatography, appears to be a very sensitive and specific predictor for the risk of respiratory distress syndrome (RDS) in newborns of normal pregnancies. To assess the effect of diabetes mellitus on fetal pulmonary maturation, we measured cholesteryl palmitate concentration, the lung profile, and total phosphatidylcholine in amniotic fluid obtained from 35 well-controlled diabetic and 39 control pregnancies at term. In women with diabetes, the mean (+/- SD) third-trimester glycosylated hemoglobin level was 6.96 +/- 2.3% (normal 6-8%). Mean cholesteryl palmitate concentration in the diabetic population was 79.12 +/- 13.17 micrograms/mL, versus 153.71 +/- 16.77 micrograms/mL in the control group (P less than .001). The mean cholesteryl palmitate concentration was also significantly different for gestational diabetics and class B-R gravidas (112.75 +/- 26.2 versus 54.45 +/- 7.34 micrograms/mL; P less than .005). Cholesteryl palmitate was decreased despite the presence of a mature lecithin/sphingomyelin ratio and, in most cases, phosphatidylglycerol. These data suggest that even in well-controlled diabetic pregnancies, alterations in maternal metabolism may affect either the biosynthesis or degradation of cholesteryl palmitate.

The effect of chronic steroid therapy on glucose tolerance in pregnancy

We analyzed the records of 26 pregnant patients receiving chronic steroids to assess the combined effect of pregnancy and glucocorticoid administration on glucose tolerance. Five patients (19.2%) developed diabetes mellitus, four of whom required insulin. In a pregnant control group of 1325 patients, 53 patients (4.0%) developed diabetes mellitus, five of whom required insulin. Glucose intolerance was significantly higher in the steroid-treated group (p = 0.003). Comparison with a nonpregnant steroid-treated control group (47 patients, 15% of whom developed diabetes mellitus) showed no significant different (p = 0.23) between the two. All pregnant steroid-treated patients developing diabetes mellitus began steroid therapy after conception, whereas none of the patients receiving steroid therapy before conception developed glucose intolerance (p = 0.012). There does not appear to be an additive effect of steroid treatment and pregnancy on glucose intolerance; however, all patients receiving steroids should undergo periodic glucose screening.

Fetal lung maturity in diabetic pregnancies: relation among amniotic fluid insulin, prolactin, and lecithin

Insulin, prolactin, and lecithin phosphorus levels were measured in 97, 62, and 44 amniotic fluid samples from third trimester normal, gestational diabetic, and insulin-dependent diabetic patients, respectively. There was no difference in lecithin phosphorus concentration (index of fetal lung maturity) among the three groups. The amniotic fluid insulin level was significantly higher in insulin-dependent diabetic patients, whereas there was no difference in amniotic fluid prolactin levels among the groups. Correlations of amniotic fluid prolactin levels with both lecithin phosphorus and insulin levels were not statistically significant in any of the groups. This is probably because amniotic fluid prolactin is decidual, rather than fetal, in origin. Even though amniotic fluid insulin levels, which reflect fetal levels, were significantly higher in insulin-dependent diabetic patients, there was no difference in the amniotic fluid lecithin phosphorus concentration in diabetic pregnancies compared with that in normal pregnancies. Moreover, there was a positive, and not a negative, correlation between amniotic fluid insulin and amniotic fluid lecithin phosphorus levels in diabetic pregnancies. These results do not support the theory that fetal hyperinsulinemia results in delayed pulmonic maturation in diabetic pregnancies.

Non-enzymatic glycation of fetal tissue in diabetic pregnancy. Estimation of the glucitollysine content of umbilical cord extracts

Non-enzymatic glycation of fetal tissue was studied by determining the glucitollysine content of umbilical cord extracts from twelve infants of diabetic mothers and fourteen infants of healthy, non-diabetic women (controls). The single, glycated amino-acid glycitollysine, which reflects the extent of glycation processes in biological samples, was measured by a standard amino acid ion exchange chromatography followed by reverse phase high pressure liquid chromatography. Infants of diabetic mothers had significantly higher cord glucitollysine levels than infants of control mothers (14.3 + 4.6 vs. 5.5 + 2.1 ng/mg dry tissue; M + SD, p less than 0.001). Moreover, five infants of diabetic mothers with congenital anomalies had strikingly high glucitollysine levels, higher than the mean +4 SD of the controls. We conclude, that non-enzymatic glycation of fetal tissue does occur as a result of an in utero exposure to cumulative glycemia. Major congenital anomalies in diabetic pregnancies are associated with a greater extent of non-enzymatic glycation of umbilical cord tissue.

Steps of glucocorticoid action in normal and diabetic rat placenta

This investigation examined the effects of Streptozotocin diabetes in pregnancy on several parameters of glucocorticoid action in the rat placenta. Pregnant diabetic rats showed reduced body weight, increased adrenal weight and serum corticosterone concentrations. Glucocorticoid receptors in placental cytosol of labyrinthine zone, measured in the absence of MoO4Na2 were similar in control and diabetic rats, but after addition of MoO4Na2 receptor number were moderately, but significantly reduced in diabetic placentas (P less than 0.01). No changes in affinity were detected in saturation analysis. Furthermore, transformation of the receptor assessed by its capacity for binding to DNA-cellulose, was enhanced in diabetic animals, suggesting increased efficiency of the receptor-bound hormone. Since the function of the glucocorticoid receptor of rat placenta may be the inhibition of local progesterone production (Heller and De Nicola, J. steroid Biochem. 19 (1983) 1339-1343), we determined progesterone synthesis in vitro and found that diabetic placentas synthesized significantly less progesterone than control tissue (P less than 0.05). Lastly, we found that the metabolism of corticosterone to 11-dehydrocorticosterone, while declining in control placentas as pregnancy advanced, it was sustained in diabetic pregnancy. It is suggested that diabetic rat placentas showed increased activity towards the glucocorticoid receptor, resulting in reduction in progesterone synthesis and sustained catabolism of corticosterone. The latter may possibly constitute a compensatory mechanism to protect the fetal compartment from high levels of maternal glucocorticoids.

Diabetes affects sorbitol and myo-inositol levels of neuroectodermal tissue during embryogenesis in rat

ATP, ADP, phosphocreatine (PCr), creatine (Cr), glucose, malate, sorbitol, and myo-inositol (MI) were measured by quantitative histochemical techniques in pure neuroectodermal tissue of rat embryos of gestation days 11 and 12 that were dissected from normal and streptozocin-induced diabetic mothers. Neither gestational age nor maternal diabetes affected the tissue's energy potential (ATP-to-ADP and PCr-to-Cr ratios). Diabetes resulted in a fourfold rise in the embryonic glucose and a 25% increase in neuroectodermal malate content. Maternal hyperglycemia caused a rise in fetal sorbitol at days 11 and 12 of gestation. The MI content of the neuroectoderm was not affected by the maternal diabetic state in perfusion embryos (day 11); however, the near doubling of MI that occurs from day 11 to day 12 during normal development was prevented. Thus, embryos isolated from diabetic mothers on gestation day 12 had 30% less MI than embryos isolated from normal mothers. From these data we conclude that a rise in tissue sorbitol is not always accompanied by a fall in tissue MI. These results and recent information in the literature implicate involvement of decreased MI concentrations in the process leading to malformation of the nervous system in diabetic embryopathy.

Relaxin as an aetiological factor in diabetic embryopathy

Relaxin, an insulin homologue, has effects on collagen resembling those of certain teratogenic agents. It is suggested that diabetic embryopathy could be due to disturbances of relaxin secretion during fetal organogenesis.

125I-human epidermal growth factor specific binding to placentas and fetal membranes from various pregnancy states

Specific binding of 125I-human epidermal growth factor (hEGF) to homogenates of term human placentas and fetal membranes from normal and appropriate for gestational age (N = 20), intrauterine growth retarded (N = 9), twin (N = 11), White class A/B diabetic (N = 12), and large for gestational age (N = 13) pregnancies was measured. In all pregnancy states, placentas bound approximately four times more 125I-hEGF than did fetal membranes (P less than 0.001). There was no significant difference in 125I-hEGF binding to fetal membranes from the various pregnancy states (P greater than 0.05). 125I-hEGF specific binding to placentas from intrauterine growth retarded or twin pregnancies was significantly greater compared with placentas from normal and appropriate for gestational age pregnancies (P less than 0.05). The binding to placentas from pregnancies complicated by White class A/B diabetes or large for gestational age infants, on the other hand, was not significantly different from that to placentas from normal and appropriate for gestational age pregnancies. 125I-hEGF specific binding did not differ between placentas from intrauterine growth retarded or twin pregnancies (P greater than 0.05). Placental and fetal membrane 125I-hEGF binding did not vary with fetal sex, maternal race, placental weight, or gestational age between 37 to 42 weeks (P greater than 0.05). Placental but not fetal membrane 125I-hEGF binding increased with increasing infant weight when appropriate for gestational age and large for gestational age infants were included (P less than 0.05, r = 0.38, N = 32) but not for intrauterine growth retarded, appropriate for gestational age, or large for gestational age infants alone.

Placental amino acid uptake in normal and complicated pregnancies

Amino acids are the essential substrates for fetal growth and catabolism. The fetus is dependent on the placenta for the provision of amino acids, the first step being concentration of amino acids within the syncytiotrophoblast for subsequent transfer to the fetus. A reliable technique for the isolation of human syncytiotrophoblast plasma membrane has been described, and the suitability of this preparation for the study of amino acid uptake and membrane transport has been well documented. Using this technique, the microvillous vesicle uptake of alpha-aminoisobutyric acid (AIB), a nonmetabolizable amino acid, has been determined over multiple time points for normal (NL) pregnancies and those complicated by pregnancy-induced hypertension (PIH), non-insulin-dependent diabetes mellitus (NIDDM) and those delivering small-for-gestational-age (SGA) neonates. There was no significant difference in AIB uptake between NL pregnancies and those complicated by PIH or NIDDM. Compared to each of the above, AIB uptake by the SGA group was significantly less at each time point. These results suggest that normal placental amino acid transport mechanisms may be altered in SGA pregnancies. If so, such alterations may interfere with the normal provision of nutrients to the fetus and ultimately contribute to impaired growth in utero.

Alterations in vitamin D metabolites and minerals in diabetic pregnancy

Vitamin D metabolites and minerals involved in bone metabolism were studied in 68 control mothers, 14 gestational diabetics and 68 insulin-dependent diabetics during pregnancy and at delivery. 25(OH)D and 1,25(OH)2D concentrations were significantly (p less than 0.001) lower in insulin-dependent diabetics than in the control or gestational diabetic groups. A similar difference was also observed between infants. 24,25(OH)2D, phosphorus and magnesium values were similar in all groups. Corrected calcium values were significantly lower in both mothers (p less than 0.001) and infants (p less than 0.05) in the insulin-dependent group than in the other two groups. Postpartum, 10% of infants of diabetic mothers received calcium therapy. Our results show alterations in vitamin D and mineral metabolism in pregnant insulin-dependent diabetics and their newborn infants and indicate observation during pregnancy and after delivery.

Gestational diabetes and impaired glucose tolerance of pregnancy in Riyadh

A total of 1088 pregnant women was screened for abnormalities in glucose metabolism at the initial antenatal visit; those with specific risk factors were screened again after 28 weeks gestation. In 210 (19.3%) plasma glucose measured 2 h after a 75 g glucose load was greater than or equal to 7.8 mmol/l (140 mg/dl). Follow-up glucose tolerance tests revealed an overall prevalence of abnormal tests of 10.3% (112 of 1088) according to the WHO criteria, of which 21 (1.9%) were diagnosed as gestational diabetes, and 91 (8.4%) as impaired glucose tolerance. This high prevalence was significantly related to age, parity and body mass index. Screening and diagnosis using criteria set by the WHO were found acceptable and are recommended to help resolve the international disagreement on diagnostic criteria of glucose metabolism abnormalities in pregnancy.

Glycogen metabolism in late gestation in fetuses of maternal diabetic rats

Fetal hyperglycemia and hyperinsulinemia, as induced by administration of streptozotocin to pregnant rats, during late gestation resulted in the onset of the major period of hepatic glycogen synthesis and accumulation at days 19-20 of gestation (22 days = term) rather than at days 20-21, as for normal fetuses. In addition, sustained high levels of liver synthase phosphatase and phosphorylase phosphatase activities prevented the normal term increase in activation of phosphorylase and inactivation of synthase in hyperglycemic/hyperinsulinemic fetuses. The suppression of term fetal changes in phosphorylase activation in particular contributed to the maintenance at term of fetal liver in a condition favoring glycogenesis rather than glycogenolysis.

Morphohistometric investigations of placentas of diabetic patients in correlation to the metabolic adjustment of the disease

In order to determination if an interdependence exists between the well-known maturational disturbances in placentas of diabetics and the quality of metabolic adjustment, a morphometric study covering 7,500 terminal villi of 50 placentas was performed. The diabetic mothers were divided into two groups according to satisfactory or unsatisfactory blood glucose values. Significant differences in placental retardation were observed between both diabetic groups and a normal control group. Although outcomes did not differ greatly between the two diabetic groups, macrosomia and the ratio of malformations in the newborns correlate with unsatisfactory metabolic management. Small-for-date babies, the need for early termination of pregnancy as well as pre-eclampsia are related to the severity and duration of the disease.

The influence of a high-protein, low-carbohydrate diet on bone development in the fetuses of rat dams with streptozotocin-induced diabetes

1. The purpose of the present study was to determine the effects of diet on the mandibles and growth centres of the long bones in the fetuses of diabetic rat dams given a normal diet compared with those given a high-protein, low-carbohydrate diet. 2. On the 9th day of gestation, the controls, groups 1 and 3, were injected with citrate buffer and given 200 and 600 g protein/kg diets respectively. Groups 2 and 4 were injected with 40 mg streptozotocin/kg body-weight and pair-fed with groups 1 and 3 respectively on the 200 and 600 g protein/kg diets. 3. On day 22, some dams were injected with either 45Ca or [14C]proline. Mandibles and long bones were removed and weighed and analysed for Ca content, 45Ca uptake, collagen and collagen synthesis. 4. The body-weights, and mandibular and long-bone weights of the fetuses in the diabetic 200 g protein/kg group were smaller than those of the non-diabetic 200 g protein/kg group, whereas those of the diabetic 600 g protein/kg group showed no difference from the non-diabetic 600 g protein/kg group. 5. The rate of collagen synthesis was higher in the fetuses of the diabetic 600 g protein/kg group than those of the non-diabetic group. Bones of the diabetic 200 g protein/kg group were lower in collagen content when compared with the non-diabetic group, whereas there was no difference between the diabetic and non-diabetic 600 g protein/kg groups.(ABSTRACT TRUNCATED AT 250 WORDS)

The reliability and clinical use of a rapid phosphatidylglycerol assay in normal and diabetic pregnancies

Lecithin phosphorus concentration, the standard fetal lung maturity test in our institution, and phosphatidylglyercol were assayed in 69, 29, and 45 amniotic fluid samples from normal (GI), gestational (GII), and insulin-dependent diabetic (GIII) women by means of thin layer chromatography and Amniostat-FLM, respectively. Lecithin phosphorus concentration greater than or equal to 0.1 mg/dl and positive or strong positive Amniostat-FLM results were considered mature. The results of both assays were concordant in 79% of the samples. The discordance rate was highest in GIII patients. In our experience, respiratory distress syndrome did not develop in neonate infants of diabetic women delivered after a mature lecithin result. With lecithin phosphorus concentration as the reference standard, the predictive value of a mature Amniostat-FLM result was 96.2%, whereas that of an immature result was 58.5%. Respiratory distress syndrome occurred in only two GIII neonates who were delivered within 72 hours of both immature lecithin and Amniostat-FLM results. These findings support the use of Aminostat-FLM as a screening test for fetal lung maturity in both normal and diabetic pregnancies. Additional tests will be necessary to evaluate further fetal lung maturity only if the results are negative.

[Studies on glucose challenge test (GCT) as a screening procedure for gestational diabetes mellitus]

A glucose challenge test (GCT) was developed as a screening procedure for the diagnosis of gestational diabetes mellitus (GDM). The method includes a 50gm oral glucose load and measurement of the plasma glucose concentration once at one hour after ingestion. The data were examined in 1,184 pregnant women seen at the outpatient clinic of our department from May 1984 to December 1986. Prior to the present study, 722 pregnant women were given a 75gm glucose tolerance test (75gGTT) and plasma glucose and IRI values were also analyzed. 1) Because glucose tolerance evaluated by the GCT was revealed to be impaired around the 28th week of pregnancy, it seems appropriate that screening for GDM should be planned during this period whenever possible. 2) The mean values obtained with GCTs performed before and after 28 weeks were 119 +/- 25mg/dl and 128 +/- 25mg/dl, respectively. 3) When the one-hour plasma glucose levels were compared after one 50 and one 75gm glucose load at intervals of less than 2 weeks, there was reproducibility in individual women with normal glucose tolerance, while the results were consistent in patients with DM or GDM. A mean difference of 18mg/dl at one hour was shown between the different glucose loads. 4) When screening for GDM was attempted in pregnant women with the 75gGTT, sensitivity and specificity were highest in the plasma glucose level at the one hour point. 5) GDM was found in the group of patients with plasma glucose levels of 155mg/dl or higher determined by GCT; the incidence was high in patients with plasma glucose levels of 160mg/dl or higher.(ABSTRACT TRUNCATED AT 250 WORDS)

Measurement of fetal surfactant production by fluorescence polarization of amniotic fluid in complicated pregnancies

The results are presented of fluorescence polarization as a method for measurement of surfactant production in 159 specimens of amniotic fluid collected from pregnant women with diabetes, hypertension, Rh immunization, premature rupture of membranes (for more than 48 h prior to delivery) and intrauterine growth retardation (IUGR). The predictability of the development of respiratory distress syndrome has been assessed by this assay. Its specificity, sensitivity and overall accuracy were similar to the lecithin/sphingomyelin (L/S) ratio. The influence of the conditions detailed on fetal lung maturation was determined, lung development being enhanced until near term by Rh immunization, rupture of membranes and hypertension with IUGR.

The significance of one abnormal glucose tolerance test value on adverse outcome in pregnancy

A matched control study of 126 women equally divided into three groups (normal oral glucose tolerance test, one abnormal test value, and gestational diabetes mellitus) was undertaken to examine the relationships among oral glucose tolerance test results, glycemic control in pregnancy, and adverse perinatal outcome. Characterization of metabolic control for the one abnormal oral glucose tolerance test value and the gestational diabetes mellitus groups (before treatment) showed no significant difference. After the start of treatment, however, a significant (p less than 0.01) difference between the groups in level of control was found. While no significant difference in the average birth weight between the three groups was discovered, the incidence of large infants (macrosomia and large for gestational age) was found to be significantly higher in the one abnormal oral glucose tolerance test group when compared with the normal (34% versus 9%; p less than 0.01) and gestational diabetes mellitus group (34% versus 12%; p less than 0.01). No significant difference for the incidence of an infant large for gestational age was found between the normal group and the patients with gestational diabetes mellitus after treatment. Neonatal metabolic disorders were found to be significantly higher for the one abnormal oral glucose tolerance test group (15%) when compared with the control and the gestational diabetes mellitus groups (3%). We conclude that, if left untreated, one abnormal value on an oral glucose tolerance test is strongly associated with adverse perinatal outcome.