The relationship between abdominal aortic intima-media thickness and lipid profile in neonates born to mothers with preeclampsia

Neonates born to mothers with preeclampsia are known to be associated with lipid alterations that might increase the risk for cardiovascular disease in adult life. The aim of this study was to investigate the effect of preeclampsia on lipid metabolism, aortic intimamedia thickness (aIMT) and subsequent atherogenic risk in newborn infants. Aortic intima-media thickness was measured in 60 neonates of mothers with preeclampsia (group I; 30 neonates of mothers with preeclampsia and group II; 30 neonates of mothers with severe preeclampsia) and 30 healthy neonates (group III). Maternal and cord serum lipid profiles were determined in all groups. Mean abdominal aIMT measurements were higher in the neonates born to mothers with preeclampsia (group I; 0.36 +/- 0.03 mm and group II; 0.36 +/- 0.04 mm) compared with the control group (group III; 0.33 +/- 0.03 mm, p = 0.006). Serum triglyceride levels were significantly higher in the neonates born to mothers with preeclampsia (group I; 39.2 +/- 42.0 mg/dl and group II; 39.5 +/- 56.5 mg/dl) compared with the control group (group III; 14.9 +/- 18.8 mg/dl, p = 0,039). Serum HDL cholesterol levels were significantly lower in the neonates born to mothers with preeclampsia (group I; 17.3 +/- 12.3 mg/dl and group II; 17.1 +/- 12.8 mg/dl) compared with the control group (group III; 27.6 +/- 13.0 mg/dl, p = 0.002). In conclusion; neonates of mothers with preeclampsia have significantly higher aIMT with lipid alterations. This may play a role in the pathogenesis of atherosclerosis in adult life.     

Influence of maternal smoking on neonatal aortic intima-media thickness,serum IGF-I and IGFBP-3 levels

Epidemiological studies have reported associations between a range of cardiovascular risk factors such as smoking and intima-media thickness (IMT). Some reports indicate that the maternal tobacco smoking causes disturbances of the endocrine status of the foetus. There are several potential mechanisms by which insulin-like growth factor I (IGF-I) could modify atherosclerotic processes either locally or in a systemic manner. The aim of this study was to investigate the influence of maternal smoking on neonatal aortic IMT (aIMT), serum IGF-I and IGF-binding protein-3 (IGFBP-3) levels. Aortic intima-media thickness was measured in 28 neonates whose mothers smoked during the pregnancy and 28 control neonates. Mean and weight-adjusted aIMT were significantly greater in the neonates whose mothers smoked (0.455 ± 0.009 mm and 0.151 ± 0.005 mm/kg, respectively) than in controls (0.403 ± 0.029 mm and 0.118 ± 0.014 mm/kg, respectively). Birth-weight of newborns whose mothers smoked was less than that of the controls. The decreases in serum IGF-I and IGFBP-3 observed in the infants whose mothers smoked were non-significant. Mean aIMT was negatively associated with birth-weight and IGF-I level. In conclusion, neonates whose mothers smoked have significantly increased aIMT. It might play a role in the pathogenesis of atherosclerosis in adult life.     

Changes in serum lipid and lipoprotein concentrations and compositions at birth and after 1 month of life in macrosomic infants of insulin-dependent diabetic mothers

The aim of this study was to determine whether macrosomia related to maternal diabetes alters lipoprotein metabolism and whether these abnormalities still persist or regress after 1 month of life. Serum lipoprotein compositions and concentrations as well as serum lipid fatty acid compositions were investigated in macrosomic infants (birth weight = 4840 ± 105 g at term) of insulin-dependent diabetic mothers at birth and after 1 month of life, and were compared to those of control infants (birth weight = 3400 ± 198 g at term) of healthy mothers. Compared to controls, at birth, macrosomic newborns had higher serum lipids, apolipoprotein A-I and B-100, and lipoprotein (very low density lipoprotein, low density lipoprotein, high density lipoprotein-2 and high density lipoprotein-3) levels. Higher percentages of C18:2n-6 in serum triacylglycerols, phospholipids and cholesteryl esters were also observed. At day 30, in macrosomics, serum triacylglycerol, apo B-100, very low density lipoprotein and low density lipoprotein levels were still significantly higher. C18:2n-6 and C18:3n-3 contents in serum phospholipids, triacylglycerols and cholesteryl esters were reduced while C20:4n-6 and C22:6n-3 contents in serum phospholipids and cholesteryl esters were enhanced, compared to control values. Conclusion Macrosomia was associated with alterations in lipoprotein compositions and concentrations at birth, some of which persisted after 1 month of life, and might play a role in the pathogenesis of diabetes and atherosclerosis in adult life. Received: 31 January 1998 / Accepted: 16 October 1998     

Aortic intima-media thickness, serum IGF-I, IGFBP-3, and leptin levels in intrauterine growth-restricted newborns of healthy mothers

Neonates with intrauterine growth restriction (IUGR) are associated with reduced concentrations of IGF-I that might contribute to arterial wall thickening. Direct atherogenic effects of leptin have been described. We aimed to investigate the relationship among abdominal aortic intima-media thickness (aIMT), serum IGF-I, IGF binding protein-3, and leptin levels in neonates with IUGR. Abdominal aIMT was measured in 40 term neonates with IUGR and in 40 controls. Mean aIMT was significantly greater in neonates with IUGR (0.45 +/- 0.03 mm) than in controls (0.39 +/- 0.04 mm, p < 0.0001). Serum IGF-I and leptin levels were lower in neonates with IUGR than in controls. There was a significant positive correlation between aIMT and gestational age, whereas a significant negative correlation was determined between aIMT and IGF-I in the IUGR neonates. For aIMT, significant associations included serum IGF-I level (beta = -0.406, p = 0.006) and gestational age (beta = 0.331, p = 0.022) in a multiple stepwise linear regression analysis. In control neonates, serum IGF-I levels were negatively related to aIMT (beta = -0.750, p < 0.001). Neonates with IUGR have significant aIMT with decreased IGF-I. IGF-I levels determine aIMT not only in neonates with IUGR but also in healthy controls.     

Troponin T and NT ProBNP Levels in Gestational,Type 1 and Type 2 Diabetic Mothers and Macrosomic Infants

This study compares NT proBNP and troponin T levels in umbilical cord arterial blood and postnatal echocardiographic findings for infants of gestational and pregestational diabetic mothers and macrosomic infants. Twenty-seven infants of pregestational diabetic mothers, 61 infants of gestational diabetic mothers and 37 macrosomic infants of nondiabetic mothers were prospectively enrolled in this study along with a control group of 58 healthy infants of mothers without any pregestational or gestational disorders as the control group. All enrollees were born after 34 weeks of gestation. For this study, umbilical cord blood was drawn during delivery to determine NT proBNP and troponin T levels. Echocardiography was performed 24–72 h after the delivery. Umbilical cord troponin T and NT proBNP levels were found to be higher in the diabetic and macrosomic groups than in the control group (all of them p < 0.001). NT proBNP levels were positively correlated with interventricular septum thickness in the pregestational and gestational infants of diabetic mothers groups (r = 0.564 and r = 0.560, respectively, p < 0.01). Both pregestational and gestational diabetic mothers were divided into two groups according to HbA1c levels in the third trimester as good (<6.1 %) and suboptimal (>6.1 %) metabolic control. In the good and suboptimal metabolic control diabetic groups, NT proBNP levels were also positively correlated with interventricular septum thickness (r = 0.536 and r = 0.576, respectively, p < 0.01). In the suboptimal metabolic control diabetic group, NT proBNP was only found to be positively correlated with the left ventricular mass index (r = 0.586, p < 0.01). While there was no correlation in the myocardial performance index between infants of diabetic mothers and the control group, the myocardial performance index of macrosomic infants was lower than that of the control group (p = 0.017). Cardiac biomarkers (NT proBNP and troponin T) were elevated in infants of diabetic mothers and macrosomic infants. While there was a positive correlation between NT proBNP levels and cardiac structure in infants of pregestational and gestational diabetic mothers, there was no relationship between NT proBNP levels and cardiac function.     

Relationship between Aortic Intima-media Thickening,Serum IGF-I and Low-density Lipoprotein Particle Diameter in Newborns with Intrauterine Growth Restriction

Much epidemiological evidence has linked low birth weight with late cardiovascular risk. In order to investigate the effect of intrauterine growth restriction (IUGR) on early atherosclerosis in the fetus, we measured aortic wall thickness (abdominal aortic intima-media thickness: aIMT) by ultrasonography in 15 neonates with IUGR and in 31 neonates considered to be appropriate for gestational age (AGA). Furthermore, we evaluated the relationship between aIMT, serum insulin-like growth factor-I (IGF-I) and low-density lipoprotein (LDL) particle size to investigate the possible effect of these atherosclerosis-related factors on the early atherosclerosis process. The results showed that the mean aIMT was significantly greater in the IUGR neonates than in the AGA neonates (least squares mean ± SE, 537 ± 24.8 vs. 471 ± 17.0 µm, p=0.037). The serum IGF-I levels were lower in the IUGR neonates than in the AGA neonates (27.9 ± 4.3 vs. 42.7 ± 2.9 ng/ml, p=0.009). A significant negative correlation was observed between aIMT and IGF-I in the IUGR neonates (r=–0.646, p=0.009); however, a positive correlation was observed between aIMT and IGF-I (r=0.416, p=0.020) in the AGA neonates. There appeared to be no relationship between aIMT and LDL particle diameter. Atherogenic small, dense LDL was not detected in the IUGR infants. In conclusion, neonates with IUGR have significant aortic thickening with decreased IGF-I, suggesting that prenatal events might predispose them to later cardiovascular risk.     

Maternal diabetes and neonatal macrosomia. II. Neonatal anthropometric measurements

Anthropometric measurements were obtained within 12 h of birth in 52 infants of non-diabetic mothers and 61 infants of diabetic mothers. Most of the diabetic patients were under good control, only ten of 61 having postpartum hemoglobin A1c levels in excess of normal. Neonates were grouped as normally-grown or macrosomic. Birthweight, crown-heel length, head circumference and skinfold thickness were measured. In each diabetes class, macrosomic neonates had larger mean length, head circumference and skinfold thickness than their normally-grown peers. At equal birthweight, neonates of gestational diabetic mothers and of non-diabetic mothers were similar in length, head circumference and skinfold thickness. Neonates of permanently insulin-requiring diabetics were similar to their non-diabetic peers in length and head circumference but had thicker skinfold thicknesses. Anthropometric measurements do not permit differentiation of the origin of neonatal macrosomia.     

Macrosomia,top of the iceberg: The charm of underlying factors

Background: Macrosomia is associated with childhood obesity. Gestational diabetes mellitus (GDM) is a risk factor for macrosomia. The aim of this large‐scale investigation was to determine the incidence, risk factors, characteristic features, and perinatal outcome of macrosomic infants. Methods: This prospective study was carried out on 6385 newborns. Demographic data included maternal age, paternal age, type of delivery, sex, parity and gestational age at delivery. Anthropometric measurements were recorded. ABO/Rh typing was performed and GDM was diagnosed. Results: Out of 6385 term deliveries, 477 infants (7.47%) were macrosomic. Incidence of GDM was 0.6% and 4.8% in the control group and in macrosomic births, respectively. Incidence of GDM(+) cases was 4% among macrosomic infants weighing 4000–4500 g. GDM(+) cases were densely populated (11%) in macrosomic infants weighing ≥ 4500 g (P≤ 0.05). Male/female ratio was significantly higher in macrosomic infants weighing ≥ 4500 g than those weighing 4000–4500 g (P≤ 0.05). High parental age was the risk factor for GDM. Blood group A was the most frequently observed type among mothers with macrosomic infants, however, blood group O was dominant in cases with GDM. In multivariate logistic regression analysis, the male infant was the most striking infant characteristic and GDM was the most striking maternal characteristic that were significantly associated with increased odds of macrosomic birth. Conclusions: This research reports the association between blood group system and macrosomia as well as parental age and GDM simultaneously. Our study reports a prevalence of GDM in both infants with normal birth weight and macrosomic newborns at the same time.     

Prolonged QT Dispersion in the Infants of Diabetic Mothers

Myocardial hypertrophy and cardiac dysfunction frequently occur in newborns of diabetic mothers. The authors hypothesized that wall hypertrophy or disproportionate left ventricular wall thickness in newborns of diabetic mothers may affect both QT and QTc dispersion. This study aimed to assess whether left ventricular hypertrophy affects the QT variables of infants born to diabetic mothers. This prospective cross-sectional study was conducted with 47 consecutively selected neonates of gestational diabetic mothers and 30 healthy neonates born to healthy mothers. All the subjects were evaluated during the neonatal period. Electrocardiography with echocardiography was performed for the patients and the control subjects. The newborns of the diabetic mothers were classified according to septal thickness as group 1 (16 newborns with septal hypertrophy) or group 2 (31 newborns without septal hypertrophy). The study group consisted of three cohorts: groups 1, 2, and 3 (control group). Both QT and QTc dispersion were computed from a randomly selected beat as well as from an average beat derived from 12 beats included in a 10-s electrocardiography. A total of 16 infants (34 %) had a septal thickness of 6 mm or greater. The left ventricular end-systolic diameter in group 1 was smaller (p = 0.0029) than in groups 2 and 3 (p = 0.003). The interventricular septal thickness at end diastole (IVSTd) and the left ventricular posterior wall thickness at end diastole in group 1 were higher than in of groups 2 and 3. The QT and QTc dispersion intervals were longer in group 1 than in groups 2 and 3 (p < 0.001), and a highly significant positive correlation was detected between IVSTd and QT dispersion (r = 0.514, p = 0.042). Elevated QT and QTc dispersions may be risk factors for the development of arrhythmias in newborns of diabetic mothers. These patients may critically need systematic cardiac screening.     

Aortic intima–media thickness in nicotine-exposed rat pups during gestation and lactation period

There have been several studies confirming an association between maternal smoking during pregnancy and low birth weight. The detrimental effect of nicotine exposure beginning in fetal life continues during lactation, in infancy and in the early childhood period. In our previous studies, we found increased aortic intima–media thickness (aIMT) as a preatherosclerotic lesion in neonates with intrauterine growth restriction and in infants of smoking mothers. We aimed to evaluate histopathologically the effect of nicotine exposure during pregnancy and lactation period on fetal growth and aIMT at postnatal 45 days of age (end of the mid-adolescent period) in rat pups living in the same conditions. Gravid rats were assigned into three groups. In nicotine A, pregnant rats received 6 mg/kg/day nicotine intraperitoneally during pregnancy from 1 to 21 days of gestation and lactation (until postnatal day 21). Nicotine B received 3 mg/kg/day nicotine for the same period. Control pregnant rats received only saline intraperitoneally. Abdominal aIMT was studied histopathologically at postnatal 45 days of age. Nicotine exposure resulted in decreased birth weight and pregnancy weight gain. The mean aIMT values of the rat pups exposed to nicotine in both nicotine A and B groups were higher than those of the control group (103.78 ± 21.33 μm, 99.11 ± 30.12 μm, and 62.56 ± 7.18 μm, respectively). In conclusion, the detrimental effect on birth weight of nicotine exposure that began in fetal life is dose dependent. Nicotine exposure during intrauterine life and the lactation period causes increased aIMT in rat pups.     

Maternal diabetes and neonatal macrosomia. III. Neonatal body water estimates

Body water estimates were obtained within 12 h of birth in 52 infants of non-diabetic mothers and 61 infants of diabetic mothers. Neonates were grouped as normally-grown or macrosomic. Total body water and extracellular water were estimated from antipyrine space and corrected bromide space, respectively. Intracellular water was assumed to be the difference between total and extracellular water. Infants of diabetic mothers, whether normally-grown or macrosomic, had markedly less mean total body water than normally-grown neonates of non-diabetic mothers. No effect of neonatal macrosomia or maternal diabetes on extracellular and intracellular water estimates could be detected with the techniques used. It is suggested that changes in total body water occur as a result of excessive fat accretion during fetal life.     

Impaired serum lipids and lipoproteins in fetal macrosomia related to maternal obesity

The aim of this work was to determine lipoprotein metabolism alterations in macrosomic newborns and to see whether these lipoprotein abnormalities are parallel or not to those found in their obese or nonobese mothers. Serum lipids, apo A-I, apo B100, lipoproteins (VLDL, LDL, HDL2, and HDL3), and LCAT activity were investigated in obese and nonobese mothers and cord blood of their macrosomic or appropriate-for-gestational-age (AGA) newborns. Serum and VLDL triglyceride concentrations were higher in obese mothers of AGA newborns than in nonobese mothers. Serum triglyceride, VLDL, and apo B100 levels were higher, while serum apo A-I and HDL2 cholesterol concentrations were lower in obese mothers of macrosomic newborns than in the other groups. In their macrosomic newborns, serum lipid, lipoprotein, apo B100, and apo A-I levels were higher as compared with those of other newborns. Macrosomic newborns of nonobese mothers had lipoprotein profiles similar to those in AGA newborns. LCAT activity was similar in both mother groups and in both newborn groups. In conclusion, maternal obesity and fetal macrosomia were associated with lipoprotein abnormalities consistent with high atherogenic risk.     

Evaluation of carotid intima-media thickness, a marker of subclinical atherosclerosis, in children with cerebral palsy

Background

Respiratory and cardiovascular diseases are the most common causes of death in children with cerebral palsy.

Objective

To evaluate sonographic carotid intima-media thickness, an early marker of atherosclerosis, in children with cerebral palsy and in healthy controls.

Materials and methods

One hundred children with cerebral palsy (65 boys), mean age 6.2 (SD, 2.1) years, and 35 age-matched and sex-matched healthy controls were included. Common carotid artery intima-media thickness was measured sonographically. Differences between patients and controls were evaluated with an independent samples t-test.

Results

Age, sex distribution and levels of serum lipids were comparable between patients and controls. Average, right and left carotid artery intima-media were thicker in patients compared with controls (mean ± SD, 0.61?±?0.13 mm vs 0.40?±?0.03 mm; 0.61?±?0.14 mm vs 0.40?±?0.03 mm; 0.61?±?0.13 mm vs 0.40?±?0.03 mm, respectively; all P?Conclusion Carotid intima-media is sonographically thicker in children with cerebral palsy compared with healthy controls, which may express an increased risk of atherosclerotic diseases.     

Cardiac troponin I levels and its relation to echocardiographic findings in infants of diabetic mothers

ABSTRACT: BACKGROUND: Cardiomyopathy is noted in up to 40% of infants of diabetic mothers, and the exact mechanisms responsible for it are unknown. The aim of this study was to compare between infants of diabetic mothers (IDM) and infants of non- diabetic mothers (INDM) as regards cardiac troponin I (cTnI) levels (as a marker of cardiac dysfunction) and to examine the relationship between this marker and neonatal echocardiographic changes (cardiac structure and function). METHODS: A prospective, comparative study included eighty full term neonates during the first three days of life, during the period from April 2008 to June 2011. They were divided into 2 groups, group I: included 40 infants of diabetic mothers (IDMs)and group II: included 40 infants of non diabetic healthy mothers as a control group. RESULTS: 37.5% of the IDMs were large for gestational age and demonstrated a significantly lower blood glucose level than the control group (34.6 +/- 11.3mg/dl Vs 77.2 +/- 19.8 mg/dl respectively) , respiratory distress and cyanosis were the presenting signs in 67.5% of IDMs. Cardiac TnI on the second day of life increased significantly in infants of diabetic mothers in comparison to INDM (p < 0.006) . IDMs had a significant increase in left atrial thickness ( 11.5 +/- 1.8mm in IDM Vs 10.5 +/- 0.9mm in INDM P < 0.002*) and a significant increase in septal thickness (5.0 +/- 1.2mm in IDM Vs 4.0 +/- 0.5mm in INDM P < 0.001*). CTnI correlated positively with interventricular septum thickness (P-value = 0.002*). Cardiac TnI was significantly increased in IDMs with respiratory distress (P -value < 0.05). CONCLUSIONS: This study demonstrated a highly significant positive correlation between cTnI level on the second day of life and the left ventricular end diastolic diameter (LVED) and interventricular septum diameter (IVSD). Cardiac troponin I (cTnI) is a useful biochemical marker for monitoring myocardial injury in infants of diabetic mothers. An elevated cTnI concentration in infants of diabetic mothers with respiratory distress was a good predictor for hypertrophic cardiomyopathy and/or left ventricular dysfunction.     

Serum lipid and lipoprotein composition in infants of diabetic mothers

Diabetes mellitus (DM) alters carbohydrate and lipid metabolism to a great extent. This study was planned to determine whether infants of insulin dependent and gestational diabetic mothers have abnormal lipid metabolism. Three groups of newborns were included in the study; group I consisted of 7 infants of diabetic mothers (IDM) with insulin dependent DM (Type 1 DM), group Il of 18 infants of gestational diabetic mothers and group III of 20 control neonates whose mothers had no history of DM. Total cholesterol (TC), triglyceride (TG) and high density lipoprotein-cholesterol (HDL-C) values in groups I and II were no different compared to those in group III (p>0.05). However, low density lipoprotein-cholesterol (LDL-C) and LDL-C/HDL-C ratio were similar between groups I and II (p>0.05) but significantly higher in both infants of type I diabetic mothers and gestational diabetic mothers compared to control infants (p<0.05). Apolipoprotein A-I (Apo A-1) and apolipoprotein B (Apo B) levels, Apo A-I/Apo B and HDL-C/Apo A-I ratios were similar in between groups. However, Apo B/LDL-C ratio was significantly lower in groups I and II compared to control group (p<0.05). In conclusion, diabetes in pregnant women causes a tendency to LDL hypercholesterolemia in the offspring. These infants should be longitudinally followed up to assess whether this observation imposes an increased risk for atherosclerosis for advanced ages.     

Quantitative Ultrasound Measurement of Intima–Media Thickness of Abdominal Aorta and Common Carotid Arteries in Normal Term Newborns

The objective of this study was to measure intima–media thickness (IMT) of the abdominal aortic (aIMT) and common carotid (cIMT) arteries in normal term newborns. We measured aIMT and cIMT using high-resolution ultrasonography in 100 normal term newborns during the first 4 days of life. Mean abdominal aIMT and cIMT values of term newborns were 0.51 ± 0.041 mm (n = 100) and 0.37 ± 0.054 mm (n = 100), respectively. Maximum and minimum aIMT and cIMT values of term newborns were 0.58 and 0.42 mm and 0.47 and 0.32 mm, respectively. The intraobserver intrasubject correlation coefficients for aIMT, right cIMT, and left cIMT were 0.89, 0.91, and 0.92, respectively (coefficient of variation = 5 %). The study provides data for normal aIMT and cIMT values in normal term newborns. By establishing normal values, we can further study the aetiopathogenesis of various possible intrauterine risk factors in premature atherosclerosis in normal or intrauterine growth–retarded newborns.     

Macrosomic newborns: a 3-year review

The objective of this study was to determine the incidence, perinatal complications and the outcome of macrosomic infants. A retrospective analysis was made of macrosomic deliveries and of those admitted into the Neonatology Unit. A control group of 854 deliveries weighing between 2500-4000 g was randomly composed. The incidence of macrosomic deliveries, stillbirth rates, sex, parity, maternal age, mode of delivery, perinatal complications like birth traumas, hypoglycemia, polycythemia, asphyxia, admission rate into the neonatal intensive care unit (NICU), and outcome were analyzed. Among a total of 11,827 deliveries, 829 (7%) were macrosomic neonates. Statistical analysis showed male predominance (p = 0.0001), a significant increase in cesarean section (p = 0.0001), and higher parity for the macrosomic group (p = 0.0001). The mothers of macrosomic newborns were older (p = 0.0001). The admission frequency of macrosomic deliveries into the NICU was almost two-fold. Birth injuries were found in 53 (6.4%) macrosomic infants, and macrosomic deliveries had a two-fold risk for birth injuries. Statistical analysis showed a significant difference between macrosomics and the control group for the frequency of birth traumas (p = 0.0007), hypoglycemia (p = 0.0001) and polycythemia (p = 0.0006). There were two deaths in macrosomic group versus one among control cases. Regarding the high birth trauma and NICU admission rates of macrosomic infants, it is important to emphasize the significance of prenatal diagnosis of fetal macrosomia and of management of these high-risk pregnancies in tertiary level hospitals.     

Beta-Cell Hyperplasia in Macrosomic Infants and Fetuses of Nondiabetic Mothers

The objective of this study was to test the hypothesis that macrosomic infants of nondiabetic mothers have beta-cell hyperplasia in their pancreases. Pancreatic tissues were examined from 10 macrosomic fetuses and liveborn infants and from 10 comparison cases matched for gestational age and gender. None of the mothers had a history of diabetes and all had normal glucose screening during pregnancy. Tissues were stained with hematoxylin and eosin and a monoclonal antibody against beta cells and were analyzed using an image analysis program to evaluate the size and surface area of beta-cell clusters. Brain/liver weight ratios were calculated and compared. The total surface area and cluster size of beta cells in the pancreases of macrosomic subjects were significantly larger than in the comparison pancreases. The study subjects lacked macroscopic and histopathologic findings expected in infants of diabetic mothers. We conclude that some macrosomic fetuses and infants of nondiabetic mothers manifest beta-cell hyperplasia. This corresponds to the higher insulin levels in macrosomic infants of nondiabetic mothers described in previous clinical studies. In macrosomic fetuses the stimulus for beta-cell hyperplasia may not involve aberrant maternal glucose levels.     

Echocardiographic assessment of infants born to diabetic mothers.

Echocardiography was carried out in 31 neonates (group 1) born to diabetic mothers and 37 control infants (group 2) matched for weight and gestational age. The interventricular septum was significantly thicker in group 1 babies (mean (SD) 4.77 (1.4) mm) compared with those in group 2 (2.5 (0.7) mm); in eight it was more than 5 mm, but had regressed in six over a period of three months. There was no significant difference between the two groups in the left ventricular internal dimension, right ventricular outflow tract, or size of the left atrium or the aorta. The left ventricular mass was significantly greater in infants born to diabetic mothers. The left ventricular contractility (judged by the percentage of shortening of the internal dimension and the ejection fraction) was significantly greater in group 1. No evidence of left ventricular outflow obstruction was found on pulse Doppler echocardiography in group 1.     

High incidence of Down's syndrome in infants of diabetic mothers

The incidence of Down''s syndrome was studied in 1870 infants of diabetic mothers out of 22 300 neonates born between January 1987 and April 1994 in our institution. All pregnancies were screened for diabetes and all cases of Down''s syndrome were confirmed by chromosome analysis.
Down''s syndrome (all trisomy 21) was diagnosed in 35 infants: seven were born to mothers with gestational diabetes and 28to non-diabetic mothers. The incidence of Down''s syndrome was higher in infants of diabetic mothers (3.75 per 1000 v 1.36 per 1000) (p= 0.02) with a relative risk of 2.75. No significant difference was found in maternal age between both groups (p= 0.67) and the rate of Down''s syndrome was higher in infants of diabetic mothers when compared with infants of non-diabetic mothers of similar age.
Down''s syndrome should be added to the congenital malformations already known to occur more frequently in infants of diabetic mothers.