Complete blood count parameters for healthy,small‐for‐gestational‐age,full‐term newborns

No previous study has investigated the full range of complete blood count (CBC) parameters in small‐for‐gestational‐age (SGA) newborns. The main aim of this study was to compare CBC and peripheral smear parameters in term, healthy SGA neonates and appropriate‐for‐gestational‐age (AGA) neonates, and to establish CBC reference values for full‐term SGA newborns. One hundred thirty‐two healthy, term newborns (73 SGA and 59 AGA) were included. On day 1, we obtained 109 samples and on day 7 we obtained 77 samples. A CBC and peripheral smear were analyzed for each sample collected and group data were compared. We observed higher mean values for normoblast count, hemoglobin, hematocrit, and red blood cell (RBC) count in the SGA babies than in the AGA babies on day 1. The mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration values for the SGA babies were decreased because of the relatively high RBC count and relatively high mean corpuscular volume we observed in this group. Of the SGA newborns, 21.9% had neutropenia and 4.7% had absolute neutrophil counts lower than 1500/μl on day 1. On both day 1 and day 7, the SGA newborns had higher mean absolute metamyelocyte counts and higher mean I : T (immature : total neutrophil ratio) values than the AGA group. The SGA babies had a lower mean absolute lymphocyte count on day 7 than the AGA group. We detected thrombocytopenia in almost one‐third of the 64 SGA newborns tested on day 1. In summary, our study clearly demonstrates that CBC parameters for healthy, full‐term, SGA newborns are different from those of healthy, term AGA newborns. This is the first study that has documented different mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, metamyelocyte counts, lymphocyte counts, and I : T in SGA babies compared with AGA babies.     

Placental Expression of Peroxisome Proliferator-Activated Receptor γ (PPARγ): Relation to Placental and Fetal Growth

Background and Objective: The nuclear receptor peroxisome proliferator activated receptor γ (PPARγ) contributes to placental development and thus to the maternofetal transfer of oxygen and nutrients that allow for prenatal growth. We tested the hypothesis that placental PPARγ expression relates to placental and fetal growth. Design and Study Population: Placentas (n = 116) were collected at term delivery of singleton infants who were born small- (SGA), appropriate- (AGA), or large-for-gestational-age (LGA) (n = 32 SGA, 55 AGA, and 29 LGA). Placentas and newborns were weighed at birth. Real-time PCR was used to assess placental expression of PPARγ as compared to the housekeeping gene GAPDH. Results: PPARγ expression in placentas from AGA and LGA infants was nearly 2-fold higher than in placentas from SGA infants. Placental PPARγ expression associated positively to placental and/or fetal weight at birth, particularly within the SGA subpopulation (P = 0.001). Conclusion: PPARγ expression was found to be low in placentas of SGA fetuses and to associate positively to fetal and placental weights within this subpopulation.     

Ghrelin levels and postnatal growth in healthy infants 0-3 months of age

Objective: The effect of ghrelin on growth of the newborn has long been argued, but not fully clarified. In this study, we aimed to investigate the relationship between ghrelin levels and growth parameters in the first 3 months of life.Methods: The study included 60 babies (27 girls and 33 boys) born at gestational ages between 38-42 weeks. The newborns were divided into three groups according to the Lubchenco curves as: small for gestational age (SGA), appropriate for gestational age (AGA) and large for gestational age (LGA). The relationship between ghrelin levels and growth parameters in the third month was investigated. Results: Ghrelin concentrations were significantly higher in SGA (2.4±2.6 ng/dL) babies than in AGA (1.3±0.9 ng/dL) and LGA (1.0±0.8 ng/dL) babies. The lowest ghrelin levels were in the LGA group. In SGA infants, ghrelin concentrations were inversely correlated with change in weight (r=-0.577; p=0.001), change in length (r=-0.361; p=0.005), and change in head circumference (r=-0.387; p=0.002).Conclusion: The results show that at age 3 months, SGA infants had higher ghrelin levels than AGA and LGA infants. Our findings indicate that ghrelin may be involved in the process of catch-up growth in these infants.Conflict of interest:None declared.     

Complete blood count parameters for healthy, small-for-gestational-age, full-term newborns

No previous study has investigated the full range of complete blood count (CBC) parameters in small-for-gestational-age (SGA) newborns. The main aim of this study was to compare CBC and peripheral smear parameters in term, healthy SGA neonates and appropriate-for-gestational-age (AGA) neonates, and to establish CBC reference values for full-term SGA newborns. One hundred thirty-two healthy, term newborns (73 SGA and 59 AGA) were included. On day 1, we obtained 109 samples and on day 7 we obtained 77 samples. A CBC and peripheral smear were analyzed for each sample collected and group data were compared. We observed higher mean values for normoblast count, hemoglobin, hematocrit, and red blood cell (RBC) count in the SGA babies than in the AGA babies on day 1. The mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration values for the SGA babies were decreased because of the relatively high RBC count and relatively high mean corpuscular volume we observed in this group. Of the SGA newborns, 21.9% had neutropenia and 4.7% had absolute neutrophil counts lower than 1500/microl on day 1. On both day 1 and day 7, the SGA newborns had higher mean absolute metamyelocyte counts and higher mean I : T (immature : total neutrophil ratio) values than the AGA group. The SGA babies had a lower mean absolute lymphocyte count on day 7 than the AGA group. We detected thrombocytopenia in almost one-third of the 64 SGA newborns tested on day 1. In summary, our study clearly demonstrates that CBC parameters for healthy, full-term, SGA newborns are different from those of healthy, term AGA newborns. This is the first study that has documented different mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, metamyelocyte counts, lymphocyte counts, and I : T in SGA babies compared with AGA babies.     

Haemoglobin Concentrations and Erythropoietin Levels in Appropriate and Small for Gestational Age Infants

Capillary Hb concentration on the first day of life was registered in 201 infants with weight appropriate for gestational age (AGA) and in 99 infants small for gestational age (SGA). In both groups Hb increased towards term (P < 0.01), while the SGA infants reached higher Hb concentration at term (21.5 ± 1.9 g/dl; mean ± SD) than the AGA infants (17.9 ± 1.5 g/dl) (P < 0.001). The cord serum erythro-poietin (EP) level increased towards term equally in both groups. Delivery did not seem to influence the EP level as same values were obtained in cord serum from infants delivered by elective cesarean section as after uncomplicated vaginal delivery. No correlation was found between cord serum EP and first day capillary PCV. Postnatally a rapid fall in the EP level occurred. In healthy adults no serum EP activity was detected. It is suggested that increasing hypoxia, rapid growth, and shift from hepatic to myeloid erythropoiesis may be related to the increasing Hb concentration and serum EP level towards term. Improvement of oxygenation during air breathing may cause the decreasing serum EP level after birth.     

Fasting and post-glucose ghrelin levels in SGA infants: relationships with size and weight gain at one year of age

Wide ranges in postnatal weight gain are seen in infants born small for gestational age (SGA); most show some catch-up growth and this may be driven by increased appetite. Ghrelin, the natural ligand of the GH secretagogue receptor, has potent orexigenic effects. In adults circulating ghrelin levels are increased in anorexia, decreased in obesity and show post prandial suppression. The aim of the present study was to test the hypothesis that rate of weight gain over the first year in SGA infants may relate to variable suppression of circulating ghrelin levels. Serum ghrelin levels were measured in 1 y old infants born SGA (n = 85) and in control infants born adequate for gestatitional age (AGA) (n = 22) fasting and 10 minutes after intravenous (iv) glucose (0.5 g/Kg of 25% dextrose). Sex- and gestational age-adjusted SD scores (SDS) for body weight were calculated at birth and at 1 y, and delta weight SDS between 0-1 y was calculated as an index of postnatal weight gain. In both SGA and AGA groups, ghrelin levels reduced from fasting (mean +/- SE: 104.4 +/- 6.4 fmol/ml) to 10 minutes post-iv glucose (82.7 +/- 5.3, p < 0.005). There were no differences in ghrelin levels between SGA and AGA infants (fasting or post-iv glucose). However, in SGA infants ghrelin levels post-glucose, but not fasting, were psitively related to current length (r = 0.28, p < 0.05), weight (r = 0.23, p < 0.05) and to change in weight SDS 0-1 y (r = 0.22, p < 0.05). SGA infants who showed poor catch-up growth showed a larger decline in ghrelin concentrations post-iv glucose. In conclusion, circulating ghrelin levels rapidly decreased after iv glucose. Higher ghrelin levels or lower reductions in circulating levels following iv glucose were seen in SGA infants who showed greater infancy weight gain, suggesting that sustained orexigenic drive could contribute to postnatal catch-up growth.     

Longitudinal changes in insulin-like growth factor-I, insulin sensitivity, and secretion from birth to age three years in small-for-gestational-age children

INTRODUCTION: Insulin resistance (IR) develops as early as age 1 to 3 yr in small for gestational age (SGA) infants who show rapid catch-up postnatal weight gain. In contrast, greater insulin secretion is related to infancy height gains. We hypothesized that IGF-I levels could be differentially related to gains in length and weight and also differentially related to IR and insulin secretion. METHODS: In a prospective study of 50 SGA (birth weight < 5th percentile) and 14 normal birth weight [appropriate for gestational age (AGA)] newborns, we measured serum IGF-I levels at birth, 1 yr, and 3 yr. IR (by homeostasis model assessment) and insulin secretion (by short iv glucose tolerance test) were also measured at 1 yr and 3 yr. RESULTS: SGA infants had similar mean length and weight at 3 yr compared with AGA infants. SGA infants had lower IGF-I levels at birth (P < 0.0001), but conversely they had higher IGF-I levels at 3 yr (P = 0.003) than AGA infants. Within the SGA group, at 1 yr IGF-I was associated with length gain from birth and insulin secretion (P < 0.0001); in contrast at 3 yr IGF-I was positively related to weight, body mass index, and IR. CONCLUSIONS: IGF-I levels increased rapidly from birth in SGA, but not AGA children. During the key first-year growth period, IGF-I levels were related to beta-cell function and longitudinal growth. In contrast, by 3 yr, when catch-up growth was completed, IGF-I levels were related to body mass index and IR, and these higher IGF-I levels in SGA infants might indicate the presence of relative IGF-I resistance.     

Puberty in growth hormone-treated children born small for gestational age (SGA)

Seventy-five small for gestational age (SGA) children were studied in a randomized, double-blind, dose-response GH trial with either 1 or 2 mg GH/m(2).d. Mean (SD) age at the start of GH therapy was 7.3 (2.2) yr. Data were compared with Dutch reference data. In SGA boys, mean (SD) age at onset of puberty was 12.0 (1.0) and 11.6 (0.7) yr, and in SGA girls it was 10.9 (1.1) and 10.6 (1.2) yr when treated with 1 and 2 mg GH/m(2).d, respectively. SGA boys treated with the lower GH dose started puberty later than the appropriate for gestational age (AGA) controls; for the other GH-dosage groups there was no significant difference in age at onset of puberty compared to AGA controls. The age at menarche and the interval between breast stage M2 and menarche were not significantly different for GH-treated SGA girls compared to their peers. The duration of puberty and pubertal height gain of GH-treated SGA boys and girls were not significantly different between the two GH-dosage groups and were comparable with untreated short children born SGA. In conclusion, long-term GH therapy in short SGA children has no influence on the age at onset and progression of puberty compared to AGA controls, regardless of treatment with a dose of 1 or 2 mg GH/m(2).d. Duration of puberty and pubertal height gain were not significantly different between the GH-dosage groups.     

Insulin sensitivity and secretion are related to catch-up growth in small-for-gestational-age infants at age 1 year: results from a prospective cohort

Strong associations between low birth weight and insulin resistance have been described. However, most of these studies have been retrospective. We aimed to determine whether infants born small for gestational age (SGA: birth weight <5th percentile for gestational age) have decreased insulin sensitivity, compared with appropriate for gestational age (AGA: birth weight >10th percentile) at 1 yr of age. We studied blood lipids, fasting insulin levels, other markers of insulin sensitivity, and insulin secretion during an iv glucose tolerance test in a cohort of 85 SGA and 23 AGA 1-yr-old infants. In addition, SGA infants were stratified according to catch-up growth (CUG) in weight (WCUG) or length (LCUG) during the first year of life. At 1 yr, SGA infants had a clear tendency to higher triglycerides. Fasting insulin was significantly higher in SGA infants with WCUG, compared with those who did not catch up and AGA infants (mean +/- SEM, 32.6 +/- 4.6 vs. 14.9 +/- 2.3 vs. 21.4 +/- 3.3 pM, respectively; P < 0.05). Length increment (in SD score) was the principal determinant of postload insulin secretion (R(2) = 0.1, P < 0.01). We conclude that insulin secretion and sensitivity are closely linked to patterns of rapid WCUG and LCUG during early postnatal life. Fasting insulin sensitivity is more related to WCUG and current body mass index, whereas insulin secretion seems to be directly related to LCUG.     

Cord blood lipoprotein-cholesterol: relationship birth weight and gestational age of newborns

Umbilical plasma levels of lipoproteins-cholesterol were measured in 60 premature (less than 37 weeks), 60 small for gestational age (SGA, greater than 37 weeks), and 60 full term newborns (greater than 37 weeks) to ascertain the relationship between gestational age, infant's weight and concentration of plasma lipoprotein cholesterol. Umbilical levels of total cholesterol (TC), unesterified cholesterol (UC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) in premature newborns were significantly higher (P less than .001) than in term infants. The levels of TC, UC, HDL-C and very low density lipoprotein cholesterol (VLDL-C) were substantially higher (P less than .05) in umbilical cord plasma of SGA newborns than in cord plasma of full term newborns. Lecithin:cholesterol acyltransferase activity in cord plasma was indirectly assessed by measuring the ratio of esterified cholesterol to unesterified cholesterol (CE/UC). This ratio was significantly lower (P less than .01) in preterm and SGA than in full term newborns. In addition, plasma TC, UC, LDL-C and HDL-C levels were inversely correlated with gestational age of newborns. By contrast, CE/UC ratio had an inverse correlation with gestational age and HDL-C of the newborns. These findings suggest that the levels of TC in newborns are regulated by the uptake of LDL-C by the fetal adrenal and, additionally, by the lecithin:cholesterol acyltransferase (LCAT) activity of newborn plasma. Only by careful follow-up of hyperlipidemic neonates can the true incidence of familial hyperlipoproteinemia and the value of early diagnosis be assessed.     

Influence of nutritional status and oestradiol-17 beta on plasma growth hormone, insulin-like growth factors-I and -II and the response to exogenous growth hormone in young steers

Plasma GH profiles and circulating concentrations of plasma insulin-like growth factors-I and -II (IGF-I and -II) were examined in 20 steers on either high (3% dry matter of body weight per day) or low (1% dry matter of body weight per day) planes of nutrition with or without an implant of oestradiol-17 beta. The response of plasma IGF-I and -II to a bolus injection of bovine GH (bGH) was also investigated. Reduced feeding significantly (P less than 0.01) increased the mean concentration, peak height and integrated area of plasma GH. Treatment of steers with oestradiol at low nutrition significantly increased baseline GH concentrations. Treatment of steers with oestradiol at high nutrition significantly (P less than 0.05) increased mean, baseline, peak height, and integrated area of plasma GH. GH pulse frequency was not changed by either nutritional plane or oestradiol treatment. Basal concentrations of plasma IGF-I were significantly (P less than 0.01) decreased by reduced feeding in both the oestradiol-treated and the control group. Treatment with oestradiol increased (P less than 0.01) basal plasma concentrations of IGF-I at both high and low levels of nutrition. After i.v. injection of bGH (0.1 mg/kg body weight), an increase in plasma IGF-I was observed only in steers at high nutrition. Basal concentrations of plasma IGF-II were not altered by nutritional manipulations but were significantly (P less than 0.001) increased by oestradiol treatment. After bGH infusion only steers at high nutrition showed an increase in plasma IGF-II.(ABSTRACT TRUNCATED AT 250 WORDS)     

Elevated umbilical cord ghrelin concentrations in small for gestational age neonates

Ghrelin has orexigenic effects. It is present in umbilical cord plasma in full-term neonates, raising the prospect that ghrelin plays a role in fetal and neonatal energy balance. We measured ghrelin in small (SGA), appropriate (AGA), and large (LGA) for gestational age neonates and evaluated whether ghrelin levels are modulated by neonatal insulin and glucose concentrations. Plasma concentrations of ghrelin, insulin, and glucose were measured in cord blood sampled at birth in 123 SGA, AGA, and LGA neonates (gestational age, 24-41 wk) born to mothers with and without diabetes. Ghrelin was detected in samples from all infants. Its concentration was 40% higher in SGA neonates (mean +/- SD, 2436 +/- 657 pg/ml) compared with AGA (1738 +/- 380) and LGA (1723 +/- 269) neonates. There was a positive correlation between ghrelin and gestational age in AGA/LGA (r = 0.23; P < 0.05) and a negative correlation in SGA (r = -0.67; P < 0.005) neonates. Therefore, the difference in ghrelin between SGA and AGA/LGA neonates decreases with advancing gestational age. Birth weight z-score, maternal hypertension, and glucose concentrations were significant determinants of ghrelin concentrations. In conclusion, SGA neonates present with higher umbilical cord ghrelin plasma concentrations than AGA/LGA neonates. Ghrelin may play a physiological role in fetal adaptation to intrauterine malnutrition.     

The association between birthweight, sex, and airway function in infants of nonsmoking mothers.

The risk of respiratory illness and death is increased in infants of low birthweight for gestational age, but the underlying physiologic mechanisms remain unclear. We examined the hypothesis that airway function is diminished in infants of low birthweight for gestational age, independent of exposure to maternal smoking. Respiratory function was measured using partial and raised volume forced expiratory maneuvers in 103 infants (> 35 wk gestation; 56 boys) not exposed pre- or postnatally to maternal smoking who, according to birthweight, were either small (SGA; n = 38) or appropriate (AGA; n = 65) for gestational age. At testing, SGA infants were of similar postnatal age (mean [SD]: SGA 6.8 [2.4] wk, AGA 5.9 [2.3] wk), but remained shorter and lighter than AGA infants. In univariate analyses, FVC, forced expired volume in 0.4 s (FEV(0.4)), and FEF(75) were significantly diminished in SGA compared with AGA infants (mean [95% CI of difference]: FVC: 127 versus 143 ml [-29, -2]; FEV(0.4): 112 versus 125 ml [-24, -2]; and FEF(75): 173 versus 203 ml s(-1) [-57, -3], respectively), but these differences were no longer significant after allowing for sex and body size. Furthermore, FEF(75) was on average 35 ml s(-1) lower in boys than girls (95% CI: -61, -8). We conclude that diminished airway function in SGA infants shortly after birth appears to be primarily mediated through impaired somatic growth.     

Adiponectin levels in the first two years of life in a prospective cohort: relations with weight gain, leptin levels and insulin sensitivity

Adiponectin, a novel adipocytokine with insulin sensitizing properties, is inversely related to obesity and insulin resistance in adults. We recently reported large variations in weight gain and insulin sensitivity during the first year in infants born small for gestational age (SGA) or appropriate for gestational age (AGA). We now determined whether adiponectin levels were related to postnatal growth and insulin sensitivity in a prospective cohort followed from birth to two years old (n = 85) (55 female/30 male, 65 SGA/20 AGA). Serum adiponectin levels at one year and two years were higher compared to reported levels in adults and older children, and decreased from one year (21.6 +/- 0.6 microg/ml) to two years (15.7 +/- 0.7 microg/ml) (p < 0.05). At two years adiponectin levels were lower in females (15.3 +/- 0.4 microg/ml) than males (16.4 +/- 0.6 microg/ml) (p < 0.05), but no gender difference was seen in leptin or insulin levels. No differences in adiponectin levels were seen between SGA and AGA infants at one or two years. However, in SGA infants changes in adiponectin between one to two years old were inversely related to weight gain (r = -0.310, p < 0.05). Changes in leptin levels between one to two years were positively related to weight gain in both SGA and AGA infants (r = 0.450 and r = 0.500 respectively, both p < 0.05). Adiponectin levels were unrelated to insulin levels at one or two years, nor to change in insulin levels between one to two years. In multiple regression analysis, adiponectin levels were related only to postnatal age; omitting age from the model, the determinants of higher adiponectin levels were male gender (p = 0.03), lower postnatal body weight (p < 0.001), and higher birth weight SD score (p = 0.004). In conclusion, fall in serum adiponectin levels during the first two years of life were related to increasing age and greater weight gain SGA infants, but were unrelated to insulin sensitivity.     

Longitudinal changes in insulin sensitivity and secretion from birth to age three years in small- and appropriate-for-gestational-age children

Aims/hypothesis Insulin resistance and type 2 diabetes risk in human subjects who were small-for-gestational-age (SGA) at birth may be a consequence of rapid early postnatal weight gain. Materials and methods We prospectively studied early changes in fasting insulin sensitivity and insulin secretion, assessed by a short intravenous glucose tolerance test that was conducted several times from birth to 3 years of age in 55 SGA (birthweight below fifth percentile) newborns and in 13 newborns with a birthweight appropriate for gestational age (AGA). Results Most SGA infants showed postnatal upward weight centile crossing and by 3 years were similar in size to AGA infants. SGA infants had lower pre-feed insulin levels at postnatal age 48 h than AGA infants (median 34.4 vs 59.7 pmol/l, p<0.05), but by the age of 3 years they had higher fasting insulin levels (median 38.9 vs 23.8 pmol/l, p<0.005), which were related to rate of weight gain between 0 and 3 years (r=0.47, p=0.0003). First-phase insulin secretion did not differ between SGA and AGA infants, but SGA infants had a lower glucose disposition index (beta cell compensation) (median 235 vs 501 min mmol⁻¹ l⁻¹, p=0.02), which persisted after allowing for postnatal weight gain (p=0.009). Conclusions/interpretation SGA infants showed a marked transition from lower pre-feed insulin and increased insulin sensitivity at birth to insulin resistance over the first 3 years of life. This transition was related to rapid postnatal weight gain, which could indicate a propensity to central fat deposition. The additional observation of reduced compensatory beta cell secretion underlines the need for long-term surveillance of glucose homeostasis in all SGA subjects, whether or not they show postnatal catch-up growth.     

The GH-releasing hormone (GHRH) test in acromegaly before and after adenomectomy

The GHRH test may represent a new tool in the study of GH dynamics in acromegaly. GH responsiveness to GHRH 1-40 (50 micrograms iv) has been studied in 21 acromegalic patients. Nineteen out of 21 had active disease. Five patients were also studied 1-12 months after neurosurgery. Two apparently cured acromegalics were studied 1-2 yr after surgery. GH secretion has been evaluated in all patients by means of TRH, bromocriptine and insulin hypoglycemia tests, too. GH response to GHRH has also been performed in 14 normal subjects. In acromegaly, GH responses after GHRH (p less than 0.01 vs placebo) were variable. The GH peak ranged from 8 to 445 ng/ml in patients with active disease. Maximum GH increase after GHRH (calculated as peak/basal value ratio) was significantly reduced in acromegaly (2.9 +/- 0.5 ng/ml; mean +/- SE) in comparison to controls (34.1 +/- 10.9 ng/ml; p less than 0.01). No significant differences in GH pattern after GHRH were found between untreated and previously treated patients with active disease. A significant correlation was found between GH basal levels and GH incremental area (p less than 0.05) and between GH basal and peak levels (p less than 0.01) after GHRH. A significant increase in PRL secretion was observed in acromegalic patients after GHRH (p less than 0.01 vs placebo). No discernable variation was found in the other pituitary hormones pattern after the peptide administration. A positive correlation was observed between GH increase after GHRH and insulin hypoglycemia (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Relationship of intracellular magnesium of cord blood platelets to birth weight

Magnesium (Mg(2+)) has an important role in insulin action, and insulin stimulates Mg(2+) uptake in insulin-sensitive tissues. Impaired biologic responses to insulin are referred to as insulin resistance. Diabetic patients and obese subjects are reported to have intracellular magnesium ([Mg(2+)](i)) deficiency. Many epidemiologic studies have disclosed that restricted fetal growth has been associated with increased risk of insulin resistance in adult life. We studied the relationship of [Mg(2+)](i) in cord blood platelets to birth weight. The subjects were 19 infants who were small for gestational age (SGA) and 45 who were appropriate for gestational age (AGA). By using a fluorescent probe, mag-fura-2, we examined the basal and insulin-stimulated [Mg(2+)](i) of platelets in the cord blood. Cord plasma insulin-like growth factor-1 (IGF-1)and leptin levels were determined with the use of enzyme-linked immunosorbent assay (ELISA). Birth weight was correlated with cord plasma IGF-1 (P < .001) and leptin (P < .005). Mean basal [Mg(2+)](i), but not plasma Mg(2+), was lower in the SGA than in the AGA group (291 +/- 149 micromol/L v 468 +/- 132 micromol/L, P < .001). The basal [Mg(2+)](i) was significantly correlated with the birth weight (P < .001) as well as birth length (P < .001). At 60 seconds after stimulation with insulin, there was no significant difference in stimulated [Mg(2+)](i) between the SGA and AGA groups. Although the SGA group had low [Mg(2+)](i), the platelets had good potentiality to compensate for low [Mg(2+)](i). [Mg(2+)](i) reflects the extent of fetal growth. Decreased [Mg(2+)](i) in SGA might underlie the initial pathophysiologic events leading to insulin resistance.     

Transient cholestasis in newborn infants with perinatal asphyxia.

In asphyxiated newborn infants, cholestasis often leads to extensive investigations and a cause can rarely be found. OBJECTIVE: To assess the frequency of transient neonatal cholestasis in an unselected group of asphyxiated newborn infants in a mother-child centre. METHOD: Charts of 181 asphyxiated newborn infants born with appropriate birth weight for gestational age (AGA) or small weight for gestational age (SGA) at Sainte-Justine Hospital, Montreal, Quebec between 1989 and 1993 were reviewed. RESULTS: Transient neonatal cholestasis was found in 8.5% of asphyxiated AGA and 33% of SGA newborn infants, compared with 3.94% cholestasis of any etiology in nonasphyxiated SGA infants. Asphyxiated neonates born before the age of 35 weeks had an increased risk for transient neonatal cholestasis (odds ratio 2.84, CI 1.0-8.1) CONCLUSION: Transient neonatal cholestasis is associated with several contributing factors related to the severity of the neonatal distress. Asphyxia is frequently accompanied by cholestasis in this group of newborns and without symptoms other than uncomplicated cholestasis. Investigations should be focussed on conditions requiring immediate therapy.     

Thymulin deficiency and low 3,5,3'-triiodothyronine syndrome in infants with low birth weight syndromes

Experimental and clinical evidence indicates that thymic endocrine function is under neuroendocrine control. Recently, a positive correlation was found between plasma thymulin (a major endocrine product of thymus) and serum thyroid hormone concentrations. Low serum thyroid hormone concentrations are frequently found in premature newborn infants. In this study we measured plasma thymulin by bioassay and serum T3 and T4 in a series of healthy fullterm newborns and in premature infants with various disorders. The study subjects were 26 healthy fullterm infants, 23 fullterm small for gestational age infants, 30 preterm appropriate for gestational age (AGA) infants, 22 preterm small for gestational age infants and 30 infants with respiratory distress syndrome, of whom 15 were fullterm and 15 were preterm AGA. Blood samples were obtained 3, 5, 10, 20, and 40 days after delivery. In the healthy fullterm infants plasma thymulin concentrations were low during the first days of life and subsequently increased, reaching normal values for children aged 1-12 months by the 10th day after birth. Persistently low plasma thymulin and serum T3 levels were found in the majority of infants with pathological conditions; the lowest values for both hormones were found in infants with respiratory distress syndrome. A highly significant positive correlation was present in all groups between mean plasma thymulin and serum T3, but not T4. Short term T3 administration in 6 additional preterm AGA infants caused a significant increase in plasma thymulin titers compared to those in 6 untreated infants. We conclude that plasma thymulin is decreased in premature newborns with the low T3 syndrome and that this abnormality may be reversed by administration of T3. These findings indicate that thymic endocrine activity is modulated by thyroid function in early postnatal life.