Functional hypersomatotropism in small for gestational age (SGA) newborn infants

Basal plasma GH levels and the GH responses to an injection of 1 microgram/kg 1-44(NH2) GHRH were determined on day 3 postnatally in 5 small gestational age (SGA) twin newborns and their appropriate gestational age (AGA) co-twins, and in 10 SGA singleton newborns and 6 AGA singleton newborns. The mean basal plasma GH level was higher in the SGA than in the AGA infants but the difference was significant only for singleton newborns (p less than 0.01). The mean peak plasma GH level was markedly increased in SGA compared to AGA infants (p less than 0.05 for twins, p less than 0.01 for singletons). Twelve SGA infants re-tested at 1 month had lower basal and peak plasma GH levels (p less than 0.001 and p less than 0.01). In 21 SGA and 17 AGA infants, serum IGF-I, measured by RIA between 12 and 96 hours after birth, was significantly higher in SGA than in AGA (p less than 0.001). These results suggest that, whatever the mechanism, functional hypersomatotropism is present at day 3 in SGA infants. This hypersomatotropism may participate in the early catch-up growth process.     

Insulin resistance and body composition in preterm born children during prepubertal ages

Background Premature born children may show insulin resistance in childhood which may be due to intrauterine or postnatal adverse environmental factors. Objective Aim of this study was to evaluate insulin resistance and body composition in preterm born children born appropriate for gestational age (AGA) or small for gestational age (SGA) and relations with IGF‐I, IGFBP‐3 axis. Methods Ninety‐three preterm born children grouped as premature SGA (n = 30) and premature AGA (n = 63) were evaluated at age 4·6 ± 0·2 years and 4·7 ± 0·1 years with respect to their glucose, insulin, IGF‐I, IGFBP‐3, IGFBP‐1, leptin levels and body composition by dual‐energy X‐ray absorptiometry. Their data were compared to that of body mass index (BMI) matched term SGA (n = 42) and term AGA (n = 44) children of age 4·5 ± 0·2 and 3·8 ± 0·1 years. All children had height appropriate for their target height. Insulin resistance was evaluated by basal insulin and homeostasis model assessment for insulin resistance (HOMA‐IR). Results Basal insulin level was similar in preterm AGA (4·3 ± 1·4 pmol/l) and term AGA (7·9 ± 6·4 pmol/l) children at similar and normal BMI levels. Preterm SGA children had insulin levels (5·0 ± 3·6 pmol/l) similar to preterm AGA children but significantly lower than that in term SGA children (23·7 ± 20·8 pmol/l) (P = 0·001). Similar results were obtained for HOMA‐IR. Term SGA children had also significantly lower IGFBP‐1 levels. Body composition, leptin and IGFBP‐3 did not differ between the respective groups. IGF‐I was lower in preterm AGA (5·0 ± 0·6 nmol/l) than in term AGA (8·3 ± 1·2 nmol/l) (P < 0·001) children. Conclusions Premature born AGA and SGA children do not have insulin resistance when compared to term children if they have made a catch‐up growth appropriate for their target height and have normal BMI. The similar insulin levels in preterm SGA and preterm AGA children together with increased insulin levels in term SGA children points to the fact that it is the intrauterine restriction in the third trimester that has an adverse effect on future adverse metabolic outcome.     

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.     

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.     

Ontogeny of serum leptin concentrations in the human

OBJECTIVE: Serum leptin concentrations reflect the fat mass of an individual. Fetal growth is rapid and it might be expected that major changes in circulating leptin concentrations in the fetus and neonate take place. We have studied the ontogeny of serum leptin concentrations in cord blood samples obtained by cordocentesis between 14 and 32 weeks of gestation and in samples obtained at term. PATIENTS: Cordocentesis samples from 10 appropriately grown for gestational age (AGA) and 10 intrauterine growth restricted (IUGR) fetuses. The results were compared with cord serum leptin concentrations obtained in 39 term healthy pregnancies. RESULTS: In the AGA and term pregnancies serum leptin concentrations changed little up until 38 weeks of gestation when there was an increase in concentration (Pre 38 weeks 3.5 microg/l (SEM 0.3); Post 38 weeks 5. 6 microg/l (SEM 0.7): Mann Whitney P = 0.03). Serum leptin concentrations were similar in the AGA and IUGR fetuses (AGA 5.9 microg/l (SEM 3.0); IUGR 4.2 microg/l (SEM 1.5): Mann-Whitney P = ns). Serum leptin was strongly related to birth weight (r = 0.58; P < 0.001) and birth length (r = 0.32; P = 0.05) in the term babies but not in the AGA or IUGR groups. CONCLUSION: Serum leptin concentrations in the fetus appear to be independent of gestational age and only rise towards the end of gestation. This late change probably reflects the changes in the accretion of body fat. There appears to be little difference in serum leptin concentrations between AGA and IUGR fetuses.     

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.     

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.     

锌对胎儿生长发育影响的临床研究

为探讨锌与胎儿生长发育的关系,将66例新生儿按出生体重分为小于胎龄儿组（SGA组,出生体重小于同胎龄正常标准体重的第10百分位）及适于胎龄儿组（AGA组,出生体重在同胎龄正常标准体重的第10－90百分位）,分别测定两组脐血中锌含量及胰岛素生长因子－1（IGF－1）,胰岛素样生长因子结合蛋白－3（IGFBP－3）水平。结果显示,SGA组脐血锌含量及IGF－1、IGFBP－3水平均显著降低,与AGA组比较有显著差异（P均＜0．01）;锌浓度随出生体重和胎龄的增加而增加（P均＜0．01）,与IGF－1,IGFBP－3水平呈正相关（P均＜0．01）。认为胎儿发育与体内锌含量密切相关,缺锌可导致胎儿宫内发育迟缓,胎儿母亲孕期应适量补锌。     

Insulin, adiponectin, IGFBP-1 levels and body composition in small for gestational age born non-obese children during prepubertal ages

Background Being small for gestational age (SGA) at birth and postnatal growth pattern may have an impact on insulin resistance and body composition in later life. Adiponectin is a strong determinant of insulin sensitivity. Objective The aim of this study was to evaluate insulin resistance and adiponectin levels in SGA born children with catch‐up growth (CUG) in the absence of obesity in prepubertal ages and relations with body composition and insulin‐like growth factor binding protein (IGFBP)‐1. Methods Twenty‐four (15F, 9M) SGA born children with CUG but without obesity were evaluated at age 6·3 ± 0·5 years with respect to glucose, insulin, IGFBP‐1, leptin and adiponectin levels, and body composition by dual‐energy X‐ray absorptiometry (DEXA). Their data were compared to that of 62 (27F, 35M) appropriate for gestational age (AGA) children. Results SGA and AGA children had similar height standard deviation score (SDS) corrected for parental height and body mass index (BMI) SDS. Homeostasis model for insulin resistance (HOMA‐IR) was significantly high in SGA (0·7 ± 0·6) than in AGA children (0·4 ± 0·2) (P = 0·029). There were no significant differences in leptin, IGFBP‐1, adiponectin, and total and truncal fat between SGA and AGA children. However, being born SGA and having higher BMI in the upper half for the distribution in the sample, although within normal ranges, was associated with lower adiponectin levels (estimated means of log adiponectin levels 3·8 ± 0·3 vs. 4·4 ± 0·1 µg/ml, P = 0·040). Conclusions SGA children with CUG and with no obesity have higher insulin levels compared to AGA children. Both SGA birth and recent size seem to have an effect on serum adiponectin levels in childhood.     

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.     

Umbilical cord ghrelin concentrations in small- and appropriate-for-gestational age newborn infants: relationship to anthropometric markers

Ghrelin is a newly discovered orexigenic peptide originating from the stomach. Circulating ghrelin levels reflect acute and chronic energy balance in humans. However, it is not known whether ghrelin also plays a role in energy homeostasis during fetal life. Forty-one small-for-gestational age (SGA) and 34 appropriate-for-gestational age (AGA) infants were studied in order to determine whether cord blood ghrelin concentrations were different in SGA infants compared with AGA infants and the relationship to anthropometric measurements at delivery. The cord blood ghrelin concentrations of SGA infants (means+/-S.E.M.; 15.20+/-3.08 ng/ml) were significantly greater than of AGA infants (2.19+/-0.24 ng/ml) (P<0.0001). They were negatively correlated with the infants' birth weights (r=-0.481, P<0.0001) and with body mass index values (r=-0.363, P<0.001). The higher ghrelin concentrations were found in female infants (20.42+/-4.55 ng/ml) than in males (7.05+/-2.27 ng/ml) in the SGA group (P=0.042). These data provide the first evidence that cord ghrelin levels of SGA infants are greater than those of AGA infants and it is suggested that ghrelin is also affected by nutritional status in the intrauterine period.     

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.     

Gender specificity of body adiposity and circulating adiponectin, visfatin, insulin, and insulin growth factor-I at term birth: relation to prenatal growth

CONTEXT: Fetal development is thought to be gender specific for adiposity and circulating insulin and IGF-I but not adipokinemia, as judged by serum visfatin and adiponectin at term birth. We studied the potential relationship between these gender specificities and fetal growth. SETTING: The study was conducted at a university hospital. STUDY POPULATION: Subjects included 96 strictly matched neonates born appropriate for gestational age (AGA; 24 girls, 24 boys) or small for gestational age (SGA; 24 girls, 24 boys). MAIN OUTCOMES: Outcomes included serum insulin, IGF-I, visfatin, total and high-molecular-weight (HMW) adiponectin, osteocalcin at term birth, and neonatal body composition by absorptiometry. RESULTS: Cord insulin and IGF-I levels were higher in girls than boys (P < or = 0.01), in both the AGA and SGA subpopulation. In AGA newborns, fat and lean mass were each gender specific (P < 0.0001), whereas visfatin and total and HMW adiponectin were not. Conversely, in SGA newborns, visfatin and HMW adiponectin were gender specific (higher levels in girls), whereas body adiposity was not. In SGA fetuses, the distribution of adiponectin isoforms was in both genders shifted toward HMW (P < 0.005 vs. AGA). Cord osteocalcin did not differ by either gender or birth weight. CONCLUSION: At term birth, the gender specificity of adiposity and circulating visfatin and HMW adiponectin appeared to depend on prenatal growth, whereas the gender specificity of insulin and IGF-I levels did not. The fetal shift in adiponectin isoforms may contribute to explain why SGA newborns tend to be hypersensitive to insulin.     

Phosphoisoforms of insulin-like growth factor binding protein-1 in appropriate-for-gestational-age and small-for-gestational-age fetuses

We analysed phosphoisoforms of insulin-like growth factor binding protein-1 (IGFBP-1) in maternal and cord sera from preterm and term fetus with different growth status. Phosphoisoforms were separated by non-SDS-polyacrylamide gel electrophoresis and detected by immunoblot. Phosphoisoforms were also analysed by anion exchange chromatography on HPLC. The proportion of non-phosphorylated IGFBP-1 to total IGFBP-1 was significantly higher in preterm fetus than in their mothers, however, the relative amounts of each IGFBP-1 isoforms were similar between preterm and term fetus. The levels of non-phosphorylated IGFBP-1 were similar between appropriate for gestational age (AGA) and small for gestational age (SGA) fetus at term, however, phosphorylated isoforms of IGFBP-1 were increased in SGA fetus compared to those of AGA fetus and the proportion of non-phosphorylated IGFBP-1 to total IGFBP-1 was lower in SGA fetus than those in AGA fetus. Thus, the profiles of non-phosphorylated and phosphorylated IGFBP-1 in the fetus varies corresponding to fetal growth suggesting that not only total amounts of IGFBP-1 but also the proportion of phosphoisoforms of IGFBP-1 is important for fetal growth.     

Cord blood leptin concentrations in relation to intrauterine growth

OBJECTIVE: Leptin, a hormone that signals the amount of energy stores to the brain, has recently been shown to play a role in the regulation of several hypothalamic pituitary axes, including the growth hormone axis. To investigate a potential association between cord blood leptin concentrations and intrauterine growth we measured leptin concentrations in the cord blood of small for gestational age (SGA), appropriate for gestational age (AGA) and large for gestational age (LGA) healthy newborns. PATIENTS AND MEASUREMENTS: Cord blood leptin concentrations were evaluated in 25 SGA, 100 AGA, and 45 LGA, neonates. RESULTS: Leptin was detectable in all newborns in concentrations comparable with those found in adults. Moreover, SGA newborns had lower leptin concentrations (3.70 +/- 1.81 micrograms/l) than AGA (5.65 +/- 4.98 micrograms/l) and LGA newborns (11.99 +/- 7.06 micrograms/ l)(P < 0.01). Cord blood leptin concentrations were significantly associated with ponderal index, cord blood insulin concentrations, placental weight and maternal serum leptin concentrations. Importantly, the association between cord blood leptin concentrations and intrauterine growth status persisted after adjusting for adiposity, placental weight, maternal serum leptin concentrations and cord blood insulin concentrations. CONCLUSIONS: Cord blood leptin concentrations are independently associated with intrauterine growth. Future studies are needed to elucidate the underlying mechanism and clarify the role of leptin in regulating growth and controlling appetite in newborns.     

Hypersecretion of FSH in infant boys and girls born small for gestational age

Prenatal growth restraint, as reflected in a low birthweight for gestational age, is a risk factor for postpubertal FSH hypersecretion and for reduced gonadal size. The ontogeny of the low-birthweight effect on the FSH-inhibin B feedback loop is unknown. Infancy is an episode of choice to study the possibility of an early low-birthweight effect on the FSH-inhibin B loop because this phase is characterized by high activity within the gonadal axis. We assessed serum concentrations of FSH and inhibin B in 46 infants [26 girls and 20 boys; mean age, 4 months; range, 3-6 months; 17 appropriate for gestational age (AGA), 29 small for gestational age (SGA); mean birthweight, 3.2 kg for AGA vs. 2.3 kg for SGA], together with circulating levels of LH, E2, and free androgen index. In SGA girls and boys, serum FSH levels were 2- and 4-fold higher (P < 0.001), respectively, than in AGA controls of the same gender (7.3 +/- 0.9 vs. 3.8 +/- 0.4 IU/ml and 2.9 +/- 0.5 vs. 0.7 +/- 0.2 IU/ml). Serum LH, inhibin B, and free androgen index/E2 concentrations were similar in AGA and SGA infants. In conclusion, prenatal growth restraint was found to be followed by elevated serum FSH concentrations in infant girls and boys. SGA infants seem to need an augmented FSH drive to fulfill inhibin B requirements on the afferent side of the feedback loop. The late-endocrine correlates of early growth restraint are herewith extended to include the main axis of reproduction in both genders. It remains to be studied whether FSH hypersecretion in infancy is a marker of subsequent subfertility.     

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.     

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.     

Effect of intraamniotic fluid thyroxine injection on fetal serum and amniotic fluid iodothyronine concentrations.

Seven hundred micrograms of T4 were injected into the amniotic cavity 24 h before delivery of five pregnant women scheduled for elective cesarean section at term. T4, T3, and rT3 concentrations were measured by RIA in amniotic fluid obtained at the time of the injection and in amniotic fluid and cord serum samples collected at delivery. Iodothyronine concentrations also were determined on cord samples from 24 full term control infants. The geometric mean serum T4 concentration in the experimental infants was 27.2 micrograms/dl, almost 3 times that of the control population (10.3 micrograms/dl); serum rT3 concentrations were markedly elevated to a mean of 657 ng/dl, compared to 254 ng/dl in control infants. The mean serum T3 concentration was slightly but significantly increased to 61.3 ng/dl (control, 48.3 ng/dl; P less than 0.02). Amniotic fluid T4, T3, and rT3 concentrations all increased significantly. T4 injection into the amniotic fluid is an effective method of increasing fetal serum T4 concentrations. The preferential pathway of monodeiodination of the injected T4 in the human fetus is to rT3 rather than T3.     

新生儿脐血血脂水平及胎心率检测分析

目的探讨新生儿脐血血脂水平及胎心率的变化。方法选取头胎顺产新生儿87例,测定小于胎龄儿(SGA)14例、适于胎龄儿(AGA)63例、大于胎龄儿(LGA)10例脐血血脂水平,记录胎儿娩出前5 min胎心率。并使用全自动生化分析仪测定脐血甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)和载脂蛋白AI(ApoAI)和载脂蛋白B(ApoB)水平。结果SGA组脐血TG、TC、LDL-C、ApoB水平均高于AGA组和LGA组,HDL-C、ApoAI水平低于AGA组和LGA组,差异有统计学意义(P<0.05);新生儿血脂指标与胎心率回归分析未发现明显相关性(P>0.05)。结论不同的宫内环境引起胎儿代谢的改变,胚胎生长受限的新生儿存在血脂代谢障碍。