Amylin peptide levels are raised in infants of diabetic mothers

Background: Amylin is a novel 37 amino acid peptide hormone that is co-secreted with insulin from the pancreas in response to food intake. As a potent inhibitor of gastric emptying it plays an important role in the control of carbohydrate absorption. Feed intolerance is common in infants of diabetic mothers (IDM). Aims: To establish a normal range of amylin levels in healthy neonates, and to determine whether serum amylin levels are raised in IDM. Methods: A serial sample of 221 infants ?28 weeks gestation was enrolled prior to delivery over a 12 month period. Blood samples collected immediately after birth (umbilical cord), and at the routine Guthrie test were analysed for amylin and insulin levels. Results: Amylin levels in umbilical cord (n = 181) and Guthrie samples (n = 33) of healthy infants were 5.7 (3.0–9.1) and 6.9 (2.9–9.0) pmol/l respectively. IDM had significantly raised amylin levels in both cord (n = 31; 32.7 pmol/l, 25.9–48.1) and Guthrie samples (n = 8; 18.1 pmol/l, 15.3–23.6). Amylin correlated positively with insulin (n = 42; r = 0.67; 95% CI 0.4 to 0.81), birth weight (r = 0.22; 95% CI 0.08 to 0.36), and gestation (r = 0.18; 95% CI 0.03 to 0.32). Umbilical cord venous amylin levels showed agreement with arterial cord amylin levels (n = 34, mean bias –0.2, 95% CI 3.1 to –3.6). Conclusions: Amylin levels are significantly increased in the umbilical cord and Guthrie blood samples in IDM.     

Erythropoiesis in infants of diabetic mothers

Neonatal polycythemia is a well-established perinatal complication in infants of diabetic mothers (IDM). To investigate the regulation of erythropoiesis in these infants, we measured cord blood erythropoietin (EP) levels by a sensitive radioimmune assay and examined the growth of erythroid progenitor colonies in a series of IDM and control infants. Fifteen of 18 diabetic mothers were managed on a protocol emphasizing careful glycemic control throughout pregnancy; 10 had glycosolated hemoglobin values within the normal, nondiabetic range during the third trimester. Cord blood EP was elevated in one of 18 IDM and in two of 13 controls (p = NS). In IDM, cord blood EP values were higher in infants delivered following maternal labor and were inversely correlated with umbilical artery pH (r = -0.72; p = 0.006). Growth of burst forming units-erythroid was similar in IDM and controls in the presence of 0.1 to 2.0 U of exogenous EP per ml of methylcellulose medium. Individual infants tended to respond consistently over the entire range of EP doses tested. The number of burst forming units-erythroid observed did not correlate with cord blood EP, birth weight, or neonatal hematocrits. We conclude that: umbilical cord blood EP levels are generally normal in IDM delivered by mothers in whom good glycemic control is maintained throughout gestation, cord blood EP values are strongly influenced by perinatal events, and the response of erythroid progenitors to EP is intrinsically normal in IDM. These data suggest that polycythemia is an adaptive response in IDM and is not associated with a primary abnormality in erythropoiesis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Umbilical vein plasma concentrations of asymmetrical dimethylarginine are increased in male but not female neonates delivered preterm: a pilot study

BACKGROUND: Infants born term have substantially elevated plasma concentrations of the endogenous nitric oxide synthase antagonist asymmetrical dimethylarginine (ADMA) that normalize with growth. The plasma levels of ADMA in preterm newborns are unknown. SUBJECTS AND METHODS: Plasma concentrations of ADMA, symmetrical dimethylarginine (SDMA) and L-arginine were analyzed from venous umbilical cord blood samples of 19 preterm and 21 term infants by high performance liquid chromatography. RESULTS: Male preterm newborns (n=11) had higher ADMA (median [95% confidence interval (CI)]: 1.90 [1.73-2.10] micromol/l) than females born preterm (n=8; 1.57 [1.24-1.69] micromol/l; p<0.005). In term born males (n=10) and females (n=11) ADMA was significantly lower than in preterm male infants (all p<0.005), and without sex differences. SDMA and L-arginine concentrations were comparable between all groups. ADMA correlated inversely with body weight in male preterm newborns (r=-0.67; p<0.03). CONCLUSION: Male neonates delivered preterm have significantly higher umbilical cord venous plasma concentrations of ADMA compared to female neonates and infants born term. The sex difference and the time course of elevated ADMA may play a role in development and warrant further investigation.     

Ontogeny of unconjugated estriol in fetal blood and the relation of estriol levels at birth to the development of respiratory distress syndrome

Unconjugated estriol (E3) was quantified in serum of umbilical cord blood of 533 newborn infants, 360 of whom were delivered between 23 and 37 wk of gestation. Serum E3 levels rose (F = 7.71, p less than 0.0001) as a function of gestational age; the mean concentration of E3 at 37.5-42 wk of gestation (105 ng/ml, n = 173) was significantly higher than that in serum of newborns delivered at 23-28 wk of gestation (63 ng/ml, n = 33). Umbilical cord serum levels of E3 were significantly higher among newborns delivered vaginally between 31.5 and 42 wk of gestation than among newborns delivered by cesarean section (p less than 0.005). Although serum E3 levels correlated highly (p less than 0.0001) to newborn weight throughout the entire period of gestation, there was no relationship of newborn weight to umbilical serum E3 levels within a given gestational period. Also, the umbilical serum levels of E3 in male infants were similar to those of female infants at each gestational age. Significant changes in umbilical serum levels of E3 as a function of gestational age were not observed among newborns (n = 90) who developed respiratory distress syndrome (RDS). The mean umbilical serum concentration of E3 in newborns delivered at 34.5-37 wk of gestation who developed RDS were significantly lower (p less than 0.01) than that in similar aged newborns whose lung function was normal.(ABSTRACT TRUNCATED AT 250 WORDS)     

Plasma vasoactive intestinal polypeptide in the newborn infant

Vasoactive intestinal polypeptide (VIP) has been suggested as a possible contributor to the development of gastrointestinal problems. VIP is produced by nerve endings in the intestinal tract and appears to have marked effects on gut motility and its blood flow. Since necrotizing enterocolitis and feeding intolerance are common problems in the newborn, we examined the plasma VIP responses to feeding in healthy preterm and term newborn infants. Plasma VIP levels were measured in 20 full-term newborn infants (gestation of 39.4 +/- 0.9 weeks, mean +/- SD, and weight of 3,351 +/- 477 g) and 38 preterm infants (gestation of 27-35 weeks, weight of 920-2,440 g). In term infants, cord blood samples were obtained from the umbilical artery and vein and then before and after the feed. For preterm infants, blood samples were obtained prior to the introduction of oral feeds during the first week, and then before and after feeding once a week over the next 4 weeks. Feeding ranged from diluted premature formula to special care (24 calories per ounce) for the preterm, and breast milk or regular commercial formula for the term infants. Twenty-one healthy adults, age 25-42 years, were studied for comparison. In the term newborn infants, the plasma VIP levels in the umbilical venous blood were lower, although not statistically significant (p = 0.06), than the umbilical arterial blood (10.78 +/- 5.89 vs. 13.54 +/- 6.71 pmol/L), suggesting placental metabolism of VIP. After birth, there was a significant increase in plasma VIP levels (18.89 +/- 10.07 pmol/L, p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

METABOLIC EVENTS IN INFANTS OF DIABETIC MOTHERS DURING FIRST 24 HOURS AFTER BIRTH I.

ABSTRACT. Changes in plasma glucose, nonantibody-bound insulin and glucagon concentrations were studied in 32 newborn infants of diabetic mothers (IDM) during the first 24 hours after birth. Ten infants were born to White class A mothers and 22 to class B-F mothers. The infants were kept fasting during the investigative period and blood was sampled from an umbilical artery catheter. At birth, plasma glucose and glucagon levels were similar in the class A and B-F infants, whereas nonantibody-bound insulin levels were approximately 15-fold higher in the class B-F infants than in the class A infants (p<0.001). After birth, plasma glucose fell in all infants, the nadir being reached at two hours (p<0.01). Plasma glucose fell by approximately 35 % in the class A infants and 63 % in the class B-F infants (p<0.01). Eight IDM had asymptomatic hypoglycemia (plasma glucose <1.9 mmol/l) and four of these infants had glucose levels below 1.7 mmol/l and were withdrawn from further study. In the remaining four hypoglycemic IDM, plasma glucose was about 1.6-fold higher (p<0.01) and insulin about 11-fold higher (p<0.001) at birth compared to the 24 normoglycemic IDM. The hypoglycemia was attended by unchanged insulin levels in the class A infants, whereas insulin fell in the class B-F infant (p<0.01). However, during the whole investigative period, plasma insulin of the class B-F infants was higher than that of the class A infants (p<0.01). After birth, plasma glucagon increased slowly in all IDM and peak values were reached after 12 hours in the class A infants (p<0.05) and 24 hours in the class B-F infants (p<0.01). Only those infants who became hypoglycemic after birth exhibited a significant increment in plasma glucagon from 0-2 hours (p<0.05). These results suggest that neonatal hypoglycemia of IDM results from high plasma levels of nonantibody-bound insulin together with a very retarded increment in plasma glucagon levels. The degree of neonatal hypoglycemia and hyperinsulinemia of an individual IDM seems to be positively correlated to the severity of the diabetes of the mother.     

Determinants of insulin concentrations in healthy 1-week-old babies in the community: applications of a bloodspot assay

BACKGROUND: Epidemiological research into insulin secretion and insulin action would be helped by improved ability to measure insulin concentrations in large groups of healthy babies in the neonatal period. Such research is often restricted by the invasive nature of blood sampling. AIMS: We assessed the use of an assay that can measure insulin from bloodspots taken during routine Guthrie testing 7 days after delivery. STUDY DESIGN AND SUBJECTS: Insulin and glucose were measured in 366 seven-day-old infants from heel-prick bloodspots. Time since last feed and type of feed were recorded. RESULTS: Bloodspot insulin concentrations in normal 7-day-old infants were much lower (median (IQR): 15.4 pmol/l (<10-28.5)) than fasting insulin concentrations in adult males (44.3 pmol/l (30.6-72.6)) (p<0.001). Insulin and glucose concentrations were correlated (r=0.33, p<0.001). Insulin and glucose fell significantly with time from feed. Bottle fed infants had higher insulin concentrations but similar glucose concentrations compared to breast fed infants. Detailed analysis to account for confounders was limited due to the skewed distribution of time since feed and the lower limit of the assay leading to non-continuous insulin data. CONCLUSIONS: In the largest study of normal 7-day-old children to date we have shown insulin concentrations are low compared to adults and vary with glucose, time from feed, and type of feed. This validates the use of the bloodspot insulin assay as a potential research tool for large-scale epidemiological studies. However, careful study design would be required in future use to reduce the variation caused by timing and type of feeding and the problem of one third of values being at or below the lower limit of this assay.     

Observational study of maternal anthropometry and fetal insulin.

AIMS: To examine the relation between maternal body fat and fetal metabolism. METHODS: In this observational study, cord blood samples were collected from 60 infants of healthy women for the measurement of insulin and C peptide concentrations. Maternal weight, height, body mass index (BMI) and body composition (skinfold thickness measurements and bioelectrical impedance) were assessed at 13-15 weeks of gestation. Twenty five of the volunteers agreed to have a 75 g oral glucose tolerance test at 28-31 weeks of gestation. RESULTS: Positive correlations were observed with both cord insulin or C peptide concentrations and maternal early pregnancy BMI (r=0.44, p=0.002 and r=0.33, p=0.008, respectively). There was no significant correlation between cord insulin or C peptide concentrations and birthweight or birth weight centiles. CONCLUSION: Maternal BMI could be a predictor of fetal cord insulin concentration.     

Insulin-like growth factor binding protein-1 and interleukin-6 are markers of fetal stress during parturition at term gestation

OBJECTIVE: Maintaining an adequate blood glucose level is essential for neuron integrity. The increased energy demand imposed on the fetus by the birth process in combination with a limited glucose production capacity therefore threatens brain function. It is logical to presume that mechanisms increasing glucose mobilization as well as decreasing peripheral glucose utilization has evolved to preserve brain function, even after complicated deliveries. DESIGN: We studied umbilical cord levels of hormones involved in acute glucose regulation as well as insulin-like growth factor-I (IGF-I), modulating factors insulin-like growth factor binding protein (IGFBP)-1 and -3 as well as interleukin-6 (IL-6) in 149 infants born after different degrees of birth stress. We measured glucose, insulin, IGF-I, IGFBP-1, IGFBP-3, glucagon, growth hormone (GH), prolactin, adrenocorticotropin (ACTH), cortisol and IL-6 in umbilical cord blood of infants born at term gestation after: A) elective Cesarean-section (n = 37), B) normal delivery (n = 87) or C) complicated delivery (n = 25). All infants were of normal birth weight for gestational age. Arterial pH and lactate as well as S-100B, a marker of neuronal damage, were used as stress variables. RESULTS: With increasing fetal stress, we found significant and generally progressive elevations in glucose, IGFBP-1, IL-6, ACTH, cortisol, glucagon, GH, prolactin and lactate. This was accompanied by significant decreases of IGF-I, insulin and arterial pH. S-100B and IGFBP-3 levels did not differ between groups. IGFBP-1 showed a significant positive correlation to IL-6 and lactate and a significant negative correlation to both IGF-I and arterial pH. CONCLUSIONS: Increasing stress and energy demands during birth are accompanied by increasing fetal levels of glucose-mobilizing hormones in combination with depressed levels of insulin and IGF-I, despite increasing blood glucose. Furthermore, IGFBP-1 and IL-6 increase steeply, presumably aimed at diminishing insulin-like activity of IGF-I, thereby reducing peripheral glucose utilization. We believe that IGFBP-1 and IL-6 deserve evaluation as potential intrapartum indicators of fetuses at risk for asphyxia.     

Metabolic events in infants of diabetic mothers during first 24 hours after birth. I. Changes in plasma glucose, insulin and glucagon

Changes in plasma glucose, nonantibody-bound insulin and glucagon concentrations were studied in 32 newborn infants of diabetic mothers (IDM) during the first 24 hours after birth. Ten infants were born to White class A mothers and 22 to class B-F mothers. The infants were kept fasting during the investigative period and blood was sampled from an umbilical artery catheter. At birth, plasma glucose and glucagon levels were similar in the class A and B-F infants, whereas nonantibody-bound insulin levels were approximately 15-fold higher in the class B-F infants than in the class A infants (p less than 0.001). After birth, plasma glucose fell in all infants, the nadir being reached at two hours (p less than 0.01). Plasma glucose fell by approximately 35% in the class A infants and 63% in the class B-F infants (p less than 0.01). Eight IDM had asymptomatic hypoglycemia (plasma glucose less than 1.9 mmol/l) and four of these infants had glucose levels below 1.7 mmol/l and were withdrawn from further study. In the remaining four hypoglycemic IDM, plasma glucose was about 1.6-fold higher (p less than 0.01) and insulin about 11-fold higher (p less than 0.001) at birth compared to the 24 normoglycemic IDM. The hypoglycemia was attended by unchanged insulin levels in the class A infants, whereas insulin fell in the class B-F infants (p less than 0.01). However, during the whole investigative period, plasma insulin of the class B-F infants was higher than that of the class A infants (p less than 0.01). After birth, plasma glucagon increased slowly in all IDM and peak values were reached after 12 hours in the class A infants (p less than 0.05) and 24 hours in the class B-F infants (p less than 0.01). Only those infants who became hypoglycemic after birth exhibited a significant increment in plasma glucagon from 0.2 hours (p less than 0.05). These results suggest that neonatal hypoglycemia of IDM results from high plasma levels of nonantibody-bound insulin together with a very retarded increment in plasma glucagon levels. The degree of neonatal hypoglycemia and hyperinsulinemia of an individual IDM seems to be positively correlated to the severity of the diabetes of the mother.     

Serum amyloid A (SAA) protein and high-sensitivity C-reactive protein (hsCRP) in healthy newborn infants and healthy young through elderly adults

AIM: To determine the levels of serum amyloid A (SAA) protein and high-sensitivity C-reactive protein (hsCRP) in different age groups. METHODS: Serum samples from 70 healthy newborn infants, 80 blood donors and 81 healthy elderly individuals were analysed using a nephelometric method. The 231 samples were grouped as follows: 35 umbilical cords, 35 newborns, 48 young adults, 28 middle-aged adults, and 85 elderly adults. RESULTS: Serum levels of both SAA and hsCRP were lower in umbilical cords than in the newborns and young, middle-aged and elderly adults (p<0.0001). The SAA and hsCRP levels were comparable in newborns, and young and middle-age adults, but higher in elderly adults (p<0.0001-0.03). SAA (r2=0.159, p<0.0001) and hsCRP (r2=0.059, p<0.0001) were positively correlated with age and to each other (r2=0.385, p<0.0001). CONCLUSION: Serum levels of SAA and hsCRP in umbilical cord blood are close to the detection limit and lower than in the other age groups investigated. The elderly have generally higher levels than the younger age groups, which require higher decision levels in inflammatory diseases, including infections. In newborns and young and middle-aged adults, the lower decision levels of 10 mg/l for SAA and 5 mg/l for CRP are suggested.     

Effect of gestational age upon prealbumin and retinol binding protein in preterm and term infants

The relationships between maternal and umbilical cord levels of prealbumin and retinol binding protein (RBP) were studied in 68 mothers and in their appropriate-for-gestational-age neonates delivered between 25 and 42 weeks gestation. Arterial and venous concentrations of prealbumin and RBP in cord sera were also studied in a subsample of eight infants. In cord sera, prealbumin and RBP levels increased with gestational age (prealbumin, r = 0.47; RBP, r = 0.40, p less than 0.01), and were significantly different in neonates born at term compared to those born prematurely (mean +/- SD, prealbumin 12.0 +/- 3.9 mg/dl vs. 8.8 +/- 2.3 mg/dl, p less than 0.001; RBP, 2.3 +/- 0.8 vs. 1.8 +/- 0.5 mg/dl, p less than 0.005). No significant differences between arterial and venous concentrations of prealbumin and RBP were observed in cord blood. In maternal blood, serum prealbumin and RBP concentrations did not increase with length of gestation (25-42 weeks). Maternal prealbumin was not correlated significantly with infants' cord serum levels; the correlation coefficient for RBP was 0.29, p less than 0.05. Maternal prealbumin and RBP serum levels were approximately twice the values seen in neonates born both at term and prematurely. Although the difference between premature and full-term cord levels of prealbumin and RBP may reflect an increase in hepatic protein synthesis that occurs with maturation of the fetus and/or a change in placental function after 37 weeks gestation, neither of these factors sufficiently explains the variance in neonatal prealbumin and RBP levels.     

Whole blood ionized magnesium in neonatal acidosis and preterm infants: a prospective consecutive study

The mineral magnesium is a crucial enzymatic cofactor in the cellular bioenergetic process and alternations in magnesium metabolism may be associated with neurological impairment in newborn infants. Therefore, ionized magnesium (IMg) was measured in 14 newborn infants with acidosis [umbilical arterial cord pH 7.00 +/- 0.06, Apgar score 8.3 +/- 1.6 after 5 min, gestational age (GA) 276 +/- 16 d] and 15 premature infants (umbilical arterial cord pH 7.31 +/- 0.07, GA 236 +/- 12 d). Nineteen healthy mature infants served as controls. Arterial umbilical cord samples were taken immediately after delivery and capillary blood samples were taken 2, 6, 12 and 24 h after delivery by heel stick. IMg was measured by NOVA 8. The results showed an increased umbilical cord blood IMg in infants with acidosis compared with both premature and normal infants (0.58 +/- 0.08 mmol l(-1) vs 0.51 +/- 0.03 mmol l(-1) and 0.49 +/- 0.03 mmol l(-1); p < 0.0001). In infants with acidosis IMg declined significantly 2 h after delivery to 0.49 +/- 0.05 mmol l(-1) (p < 0.0001) and did not show any further significant changes during the first day of life. In premature infants and controls IMg levels were constant during the observation period. Conclusion: These findings suggest that elevated IMg is associated with neonatal acidosis.     

Cord blood bilirubin and prediction of neonatal hyperbilirubinemia and perinatal infection in newborns at risk of hemolysis

ObjectiveTo assess the accuracy of umbilical cord bilirubin values to predict jaundice in the first 48 h of life and neonatal infection.MethodNewborn infants treated at a regional well-baby nursery born at ≥36 weeks of gestation were included in this retrospective cohort study. All infants born in a 3-year period from mothers with O blood type and/or Rh-negative were included and had the umbilical cord bilirubin levels measured. Hyperbilirubinemia in the first 48 h was defined as bilirubin levels above the phototherapy threshold. Neonatal infection was defined as any antibiotic treatment before discharge.ResultsA total of 1360 newborn infants were included. Two hundred and three (14.9%) newborn infants developed hyperbilirubinemia in the first 48 h of life. Hyperbilirubinemic infants had smaller birth weight, higher levels of umbilical cord bilirubin, a higher rate of infection and were more often direct antiglobulin test positive. Umbilical cord bilirubin had a sensitivity of 76.85% and a specificity of 69.58% in detecting hyperbilirubinemia in the first 48 h, with the cut-off value at 34 μmol/L. The area under the receiver operating characteristic curve was 0.80 (95% CI: 0.78–0.82). Umbilical cord bilirubin had a sensitivity of 27.03% and specificity of 91.31% in detecting perinatal infection. The area under the receiver operating characteristic (ROC) curve was 0.59 (95% CI: 0.57–0.63).ConclusionsA positive correlation was found between umbilical cord bilirubin and hyperbilirubinemia in the first 48 h of life. Umbilical cord bilirubin is a poor marker for predicting neonatal infection.     

Plasminogen activators and plasminogen activator inhibitors in plasma of premature and term newborns

Objective : To compare the plasminogen activators (tPA, uPA) and their inhibitors (PAI-1, PAI-2) at different gestational ages, related to levels in women at term and non-pregnant women. Methods : Blood samples were obtained by puncture of the umbilical cord vein, in gestational weeks 39–40 ( n = 21), 30–32 ( n = 15), and 27–29 ( n = 9). Analyses of PA and PAI antigen concentrations and of PAI-1 activity were performed. Results : The mean tPA antigen level in term newborn infants was 14.5 μg/l compared to the premature newborns (7.0 μg/l) women at term (7.5 μg/l) and non-pregnant women (2.3 μg/l). PAI-1 activity and PAI-2 antigen concentrations were also higher in term newborn than in premature infants. Conclusions : The plasma levels of the plasminogen activators and inhibitors are higher in term newborn compared with premature newborn infants, reflecting maturation of protein synthesis.     

Sonographic morphology and hyaluronan content of umbilical cords of healthy and Down syndrome fetuses in early gestation

OBJECTIVE: To explore the sonographic vascular architecture and the hyaluronan amount and distribution of umbilical cords of healthy and trisomy 21 fetuses in early gestation. MATERIAL AND METHODS: Umbilical cord sonographic morphology and morphometry of 112 consecutive normal fetuses and 11 trisomy 21 fetuses were assessed between 10 and 15 weeks of gestation. The umbilical coiling index was defined as the reciprocal of the length of one complete coil measured in a longitudinal section of the umbilical cord. The umbilical coiling angle was defined as the maximum angle between the long axis of the umbilical cord and that of the umbilical arteries. Three umbilical cord samples obtained from Down syndrome fetuses and one from a healthy fetus after voluntary termination of pregnancy at 13 weeks of gestation were used for biochemical analysis. Quantitative hyualuronan content and tissue distribution was studied using fluorophore-assisted carbohydrate electrophoresis (FACE) analysis and staining methods using biotin-labeled hyaluronan-binding protein (bHABP), respectively. RESULTS: A significant correlation was present between gestational age and both the umbilical coiling index (r=-0.56, p<0.001) and the umbilical coiling angle (r=-0.43, p<0.001). The proportion of uncoiled umbilical cords was significantly higher in Down syndrome fetuses than in healthy fetuses [8/112 (7.1%) vs. 4/11 (36.4%), p<0.05]. Biochemical analysis demonstrated a higher amount and a different distribution of hyaluronan in trisomy 21 umbilical cords compared to healthy fetuses. CONCLUSION: The umbilical cord of Down syndrome fetuses in early gestation shows peculiar sonographic vascular features and quantitative alterations of the Wharton's jelly hyaluronan.     

Placental transfer and decay of varicella-zoster virus antibodies in preterm infants

OBJECTIVES: To compare the placental transfer of maternal varicella-zoster (VZV) antibodies to preterm and term infants and to investigate antibody decay during the first 6 months of life in the preterm infants.Study design: Maternal and umbilical cord blood samples were taken from 113 healthy mother-newborn pairs: 64 term (gestational age > or =37 weeks) and 49 preterm (gestational age < or =35 weeks). Premature infants were further tested at 1, 2, and 6 months. Anti-VZV antibody to membrane antigen was measured with the immunofluorescent technique. RESULTS: Preterm infants of gestational age < or =28 weeks had positive cord antibody and a geometric mean titer significantly lower than those in preterm infants of gestational age 29 to 35 weeks and term infants (25% vs 95% and 95%, respectively, P <.001 for each, and 2.5 +/- 2.2 vs 10.5 +/- 2.4 and 12.6 +/- 2.4, respectively, P <.001 for each). There was no difference between the preterm 29 to 35 weeks of gestation and term groups. Fetal-maternal ratios for both preterm groups were <1 and were significantly less than the fetal-maternal ratio in the term infants. The transfer of maternal antibodies to term infants was significantly greater than to the 29- to 35-week preterm infants (P =.01). At 2 months of age, 25% of 29- to 35-week preterm infants and no preterm infant < or =28 weeks had a positive titer. At 6 months of age, all preterm infants were seronegative, and the geometric mean titer in both groups declined to undetectable levels. CONCLUSION: Transplacental transfer of maternal VZV antibodies is diminished in preterm infants. VZV antibody levels are significantly lower in preterm infants born at < or =28 weeks' gestational age compared with those in preterm infants 29 to 35 weeks' gestational age and term infants. Anti-VZV titers decrease to undetectable levels in preterm infants by 6 months of age or earlier; thus these infants appear to be susceptible to chickenpox before the scheduled 12-month vaccination.     

Neonatal hypoglycaemia in infants of diabetic mothers

OBJECTIVE: To determine whether umbilical cord blood glucose correlates with subsequent hypoglycaemia after birth in infants of well-controlled diabetic mothers. METHODOLOGY: Thirty-eight term infants of well-controlled diabetic mothers were enrolled. Five mothers had pre-existing diabetes. Of the 33 gestational diabetic mothers, 16 were managed on insulin and 17 on diet. Maternal blood glucose was maintained between 4 and 8 mmol/L during labour and delivery. Infants' plasma glucose levels were measured from venous cord blood and serially, at less than 30 min, 1 h and 2 h of life by glucose hexokinase method. Blood glucose levels were further monitored by bedside Dextrostix for 24 h. RESULTS: Eighteen (47%) infants developed hypoglycaemia (blood glucose level less than 2 mmol/L) during the first 2 h of life. There was no difference in the cord blood glucose levels between infants with or without hypoglycaemia (3.7 +/- 1.1 vs 4.5 +/- 1.1 mmol/L, respectively). Infants of mothers with diabetes diagnosed prior to 28 weeks gestation were at a higher risk of developing hypoglycaemia (8 of 10 vs 10 of 28, OR 7.2, 95%CI 1.3-40.7). Hypoglycaemic infants were of significantly higher birthweight, and were more likely to be born to Caucasian mothers and by Caesarean section. Raised maternal fructosamine blood level, the need for insulin treatment or the infant's haematocrit were not different between infants with or without hypoglycaemia. CONCLUSIONS: In well-controlled diabetic mothers, the incidence of early hypoglycaemia in infants is still high, particularly in those mothers who had a longer duration of diabetes. Cord blood glucose level did not identify the infants with hypoglycaemia.     

The association of nuchal cord with cerebral palsy is influenced by recording bias

OBJECTIVES: To determine if the association of cerebral palsy (CP) with umbilical cord around the fetal neck (nuchal cord) is the result of recording bias. STUDY DESIGN: Population-based case control study. RESULTS: There were 68 cases with cerebral palsy and 157 controls (singleton term infants matched for gestational age and hospital of birth). CP was associated with tight nuchal cord overall (OR=2.8, 95% CI 1.1-6.8). Where cord around the neck is recorded at the discretion of the accoucheur (37 cases, 97 controls), there was an association between tight nuchal cord and CP (OR=5.4, 95% CI 1.4-20.4) and, in controls only, between Apgar score <7 at 1 min (OR=16.9, 95% CI 1.4-456.3). In the hospital where records included a tick box for nuchal cord (31 cases, 60 controls), an association between CP and tight nuchal cord could not be demonstrated (OR=1.4, 95% CI 0.4-4.9). Nor was there an apparent association between nuchal cord and Apgar score <7 at 1 min (OR=2.6, 95% CI 0.4-15.9) in controls. CONCLUSIONS: The presence of nuchal cord is subject to recording bias. In a retrospective study, this can lead to an association of CP with nuchal cord that is not evident where documentation is systematic.     

Cord and placenta arterial gas analysis: the accuracy of delayed sampling

AIM: To determine the accuracy of delayed arterial gas sampling (1) from the umbilical cord and (2) from the placental surface at room temperature. METHODS: Term deliveries were classified a priori into three groups: normal vaginal deliveries, elective caesarean sections and high risk deliveries. The cord was double clamped and paired arterial samples were taken from the cord and the placenta at 0, 30, 60 and 90 min. RESULTS: 90 placentas were sampled with 30 cases per group. At time 0 the mean cord pH 7.207 (+/-0.08) was significantly lower than the placenta pH 7.240 (+/-0.08). The cord pH dropped significantly: by 0.050 (95% CI 0.036 to 0.063) at 30 min, 0.087 (95% CI 0.069 to 0.105) at 60 min, and 0.112 (95% CI 0.086 to 0.138) at 90 min. The placenta pH fell at twice the rate of the cord pH over 90 min. At time 0 the mean cord base excess -7.0 mmol/l (+/-4.1) was significantly lower than the placenta base excess -6.3 mmol/l (+/-3.6). The cord base excess fell at 30 min by 4.1 mmol/l (95% CI 3.4 to 4.7), at 60 min by 7.1 mmol/l (95% CI 6.1 to 8.0), and at 90 min by 9.0 mmol/l (95% CI 7.9 to 10.0). The pH and base excess rate of fall was similar for each of the three delivery groups despite differing starting values. CONCLUSION: Arterial blood gases should be taken as soon as possible after delivery from the umbilical cord. However, when this is not possible, the arterial pH and base excess from a delayed sample from a clamped cord at room temperature can be used to estimate the values at birth.