Circulating peptide YY concentrations are higher in preterm than full-term infants and correlate negatively with body weight and positively with serum ghrelin concentrations

BACKGROUND: Peptide YY (PYY) and ghrelin are gastrointestinal tract-derived hormones that play roles in the regulation of food intake and energy balance. Negative energy balance often occurs in hospitalized preterm infants. METHODS: To measure serum concentrations of PYY in preterm and full-term infants and to investigate their correlations with anthropometric characteristics, food intake, and serum ghrelin concentrations, we measured serum PYY and ghrelin concentrations by RIA in 62 healthy preterm infants [mean (SD) gestational age, 32.0 (2.1) weeks; postnatal age, 40.9 (14.8) days] and 15 healthy full-term infants of comparable postnatal age. All of the infants were formula-fed every 3 h. RESULTS: PYY concentrations were significantly higher in preterm [1126.2 (215.4) ng/L] than in full-term infants [825.3 (234.4) ng/L; P < 0.001]. In the entire study population, serum PYY concentrations correlated negatively with gestational age and anthropometric measurements (birth weight, body weight, body length, body mass index, and head circumference) and positively with serum ghrelin concentrations, whereas there was no significant correlation between PYY concentration and caloric intake or weight gain. Multiple regression analysis, after correction for prematurity, revealed that serum PYY concentrations correlated independently with serum ghrelin concentrations and infant body weight or body mass index. CONCLUSIONS: Circulating concentrations of PYY may increase in preterm infants to compensate for the negative body-weight balance. The physiologic mechanisms behind the correlation between PYY and ghrelin remain to be elucidated.     

小于胎龄儿出生后血清维生素B12及脑发育水平研究

目的检测小于胎龄儿、适于胎龄儿出生后血清维生素B12(VB12)、同型半胱氨酸(Hcy)水平的差异并对足月儿进行行为神经评定,探讨VB12、Hcy对胎儿发育的影响及小于胎龄儿脑发育水平。方法根据胎龄与出生体质量的关系,将符合入选条件的研究对象分为小于胎龄儿组(早产小于胎龄儿亚组、足月小于胎龄儿亚组)、适于胎龄儿组(早产适于胎龄儿亚组、足月适于胎龄儿亚组),检测其血清中VB12、Hcy水平,分析出生时血清VB12、Hcy水平与出生体质量、胎龄的关系,比较小于胎龄儿、适于胎龄儿组出生时血清VB12、Hcy的水平差异。采用新生儿20项行为神经评定法(NBNA)对生后2~3 d的足月小于胎龄儿亚组、足月适于胎龄儿亚组进行行为神经测定并比较2组差别。结果出生时血清VB12水平与出生体质量呈正相关(r=0.564,P<0.05);血清Hcy水平与出生体质量呈负相关(r=-0.569,P<0.05)。早产适于胎龄儿亚组出生时血清VB12水平高于、Hcy水平低于早产小于胎龄儿亚组[VB12:(262.07±62.25)pg/ml vs(228.21±67.27)pg/ml;Hcy:(8.47±3.81)μmol/L vs(17.53±10.56)μmol/L],差异有统计学意义(P均<0.05);足月适于胎龄儿亚组出生时血清VB12水平高于、Hcy水平低于足月小于胎龄儿亚组[VB12:(431.03±113.82)pg/ml vs(254.80±72.35)pg/ml;Hcy:(4.61±2.88)μmol/L vs(13.60±9.29)μmol/L],差异有统计学意义(P均<0.05)。与足月适于胎龄儿亚组相比,足月小于胎龄儿亚组NBNA总分、行为能力、被动肌张力、主动肌张力评分均明显降低(P均<0.05)。结论出生时血清VB12水平与出生体质量、胎龄呈正相关;血清Hcy水平与出生体质量、胎龄呈负相关;小于胎龄儿出生时血清VB12水平较适于胎龄儿低,Hcy水平较适于胎龄儿高,提示VB12可能影响胎儿生长发育。足月小于胎龄儿早期NBNA评分较足月适于胎龄儿明显减低,说明小于胎龄儿出生时行为神经能力已受到影响。     

Morphine clearance and effects in newborn infants in relation to gestational age

OBJECTIVE: We sought to provide a rational basis for morphine administration in preterm infants in the immediate postnatal period by determining the clearance and evaluating the efficacy and adverse effects of a continuous infusion. STUDY DESIGN: Morphine was infused for 2 to 4 days (140 microg/kg over 1 hour followed by 20 microg/kg/h) to 31 ventilator-treated newborn infants (gestational age, 24 to 41 weeks; birth weight, 765 to 4,015 g). Morphine, morphine-3-glucuronide, and morphine-6-glucuronide concentrations in serum were determined from arterial blood obtained at 2, 12, 24, 48, and 60 hours after the start of morphine infusion at a median postnatal age of 10 hours. RESULTS: The mean +/- SD steady-state morphine concentration, 167 +/- 77 ng/mL, was achieved between 24 and 48 hours of infusion, and morphine-6-glucuronide and morphine-3-glucuronide concentrations did not reach steady state within 60 hours. Morphine clearance (range, 0.8 to 6.5 mL/min/kg) correlated significantly with gestational age (r = 0.60; P < .01) and birth weight (r = 0.55; P < .01). Pain relief did not correlate with the steady-state morphine concentration. However, significantly higher morphine concentrations were found in infants with decreased gastrointestinal motility (187 +/- 82 ng/mL) compared with those without (128 +/- 51 ng/mL; P < .05). CONCLUSIONS: Morphine should be used with caution in prematurely born infants because of its low clearance, which correlates with gestational age.     

Amoxicillin pharmacokinetics in preterm infants with gestational ages of less than 32 weeks.

The multiple-dose pharmacokinetics of amoxicillin (AM [administered twice daily in a 25-mg/kg of body weight intravenous dose]) in 17 preterm infants (11 males; gestational age, 29 +/- 1.9 weeks; birth weight, 1,175 +/- 278 g) were evaluated on day 3 of life. Blood samples were collected from an arterial catheter at 0, 0.5, 1, 2, 4, 8, and 12 h after the intravenous dose. A high-performance liquid chromatography method was used to determine AM concentrations in serum. AM pharmacokinetics followed a one-compartment open model. The glomerular filtration rates of all patients were simultaneously studied by means of the 24-h continuous inulin infusion technique. The elimination half-life, apparent volume of distribution, and total body clearance of AM (mean +/- standard deviation) were 6.7 +/- 1.7 h, 584 +/- 173 ml, and 62.4 +/- 23.3 ml/h, respectively. The mean (+/- standard deviation) AM peak and trough levels were 53.6 +/- 9.1 and 16.0 +/- 4.9 mg/liter, respectively. All infants had a serum trough level above 5 mg/liter. The total body clearance and apparent volume of distribution of AM and the clearance of inulin increased significantly with increasing gestational age. The total body clearance of AM (1.0 +/- 0.4 ml/min) and the clearance of inulin (1.0 +/- 0.3 ml/min) were similar. The total body clearance of AM increased significantly with increasing clearance of inulin. We conclude that an AM dose of 25 mg/kg every 12 h given to preterm infants in the first week of life with gestational ages of less than 32 weeks results in serum levels well above the MIC for major microorganisms involved in neonatal infections.     

Magnesium, total calcium, phosphorus, copper, and zinc in plasma and erythrocytes of venous cord blood from infants of diabetic mothers: comparison with a reference group by logistic discriminant analysis.

Concentrations of magnesium (Mg), total calcium (Ca), phosphorus (P), copper (Cu), and zinc (Zn) were investigated in plasma (Pl) and erythrocytes (Erc) of venous cord blood of 44 infants of diabetic mothers (IDMs). These same concentrations plus total glycohemoglobin and fructosamine were determined at delivery in a subset of 15 mothers of these infants. Mineral results for IDMs were compared with those for 66 apparently healthy newborns. The duration of gestation in the two groups was significantly different (P < 0.001). After adjustment for gestational age, the mean (+/- SD) differences between groups were significant for birth weight, head circumference, Erc-Mg (1.71 +/- 0.17 for IDMs vs 1.76 +/- 0.15 mmol/L for control subjects), Pl-Ca (1.96 +/- 0.32 vs 2.48 +/- 0.22 mmol/L), Pl-P (1.99 +/- 0.40 vs 1.57 +/- 0.25 mmol/L), and Erc-Cu (10.9 +/- 2.41 vs 12.9 +/- 3.00 mumol/L), but not for Erc-Zn (33.0 +/- 18.3 vs 40.4 +/- 13.6 mumol/L). The variable that best discriminated between the two infant groups after adjustment for gestational age was Pl-Ca. In the 15 mothers, Pl-Mg (0.67 +/- 0.07 mmol/L) and Pl-Ca (1.66 +/- 0.21 mmol/L) concentrations were low, Pl-Zn (9.81 +/- 3.40 mumol/L) was normal, and Pl-Cu (33.5 +/- 10.7 mumol/L) was above normal. Correlations between total glycohemoglobin and mineral values of the mothers or paired IDM mineral values were not significant. The concentration of Pl-Ca was positively correlated with Erc-Cu (P < 0.001) and Pl-Cu (P < 0.05) in the comparison group newborns but not in the IDMs.     

Alkaline phosphatase isoenzymes in the plasma of preterm and term infants: serial measurements and clinical correlations

Serial measurements of the bone and fetal intestinal isoenzymes of alkaline phosphatase (EC 3.1.3.1) in the plasma of 43 term and 43 preterm infants, from birth to six weeks later, indicate that the bone isoenzyme gradually increases over this period in both preterm and term infants fed with unsupplemented commercial formulas. Preterm babies given formula supplemented with calcium (with or without additional phosphate) had significantly lower bone isoenzyme activities for most of the study period. The concentrations of fetal intestinal isoenzyme increased, under the stimulation of milk feeding, from generally undetectable at birth to a peak during the first two weeks postpartum, and then declined. This increase was highly significantly negatively correlated with gestational age, the preterm infants having a much higher and more prolonged increase in this isoenzyme than did term infants. Unlike the adult isoenzyme, fetal intestinal alkaline phosphatase in plasma showed no relationship with blood group status.     

Effect of gestational age and birth weight on tobramycin kinetics in newborn infants

The effects of gestational age and birth weight on tobramycin kinetics were studied in 26 newborn infants with presumed or proven bacterial sepsis during the first week of postnatal age. The infants received tobramycin, 2.5 mg/kg intravenously every 12 h. Group A consisted of nine patients 28 to 30 weeks of gestational age; group B had 11 patients greater than 30 to less than or equal to 34 weeks of gestational age; and group C had six patients greater than 34 to less than or equal to 40 weeks of gestational age. Steady-state peak serum concentrations of tobramycin averaged 6.5, 7.2 and 7.1 mg/l in groups A, B and C; the corresponding trough concentration averaged 2.0, 2.3 and 1.3 mg/l. The frequency of tobramycin trough serum concentration above 2 mg/l was 44% in group A, 45% in group B and 0% in group C. Total body clearance of tobramycin averaged 1.04, 1.13 and 1.28 ml/min/kg; apparent volume of distribution averaged 0.84, 0.81 and 0.61 l/kg; and elimination half-life averaged 9.3, 8.9 and 5.6 h in groups A, B and C. Group M consisted of seven infants with 1.0-1.25 kg birth weight; group N had six infants 1.26-1.50 kg birth weight; group O had seven infants 1.51-2.0 kg birth weight; and group P had six infants 2.1-3.5 kg birth weight. Steady-state peak serum concentration of tobramycin averaged 5.7, 7.3, 7.8 and 7.1 mg/l; and the trough serum concentration averaged 2.2, 2.4, 1.9 and 1.3 mg/l in groups M, N, O and P.(ABSTRACT TRUNCATED AT 250 WORDS)     

Percentile estimates of reference values for total protein and albumin in sera of premature infants (less than 37 weeks of gestation)

We measured the concentrations of total protein and albumin in sera of 281 well-fed premature infants, gestational ages 22-36 weeks, and calculated reference values from the 10th to 90th percentiles. The mean serum albumin concentration (27.6 +/- 4.4 g/L, mean +/- SD) and total protein concentration (49.2 +/- 6.7 g/L) at a postnatal age of 14.5 days were lower than reference values for full-term infants. We detected a significant positive correlation between albumin concentration and gestational age (r = 0.34, p less than 0.01) and total protein concentration and gestational age (r = 0.43, p less than 0.01). Even though albumin values were low, generalized edema was not present. We conclude that values for total protein and albumin in the preterm infant are lower than in the full-term infant but are an expected physiological response to premature birth.     

Assessment of copper status in pregnancy by means of determining the specific oxidase activity of ceruloplasmin

BACKGROUND: Conditions not directly related to copper nutriture, such as pregnancy, infections and inflammation, which increase serum copper concentration even during copper deprivation, may be expected to conceal changes in copper status. It has been suggested that the specific enzymatic activity of ceruloplasmin (activity per unit mass of enzyme protein) may be a sensitive indicator of copper status and is not affected by factors such as hormones or sex. In this study, we investigated the behaviour of specific oxidase activity of ceruloplasmin and the copper/ceruloplasmin ratio in pregnant women. METHODS: Copper, immunoreactive ceruloplasmin and its oxidase activity were determined in serum from 52 women in the last trimester of normal pregnancy, and in 50 control women of similar age living in the same area and who were not taking oral contraceptives. The results are expressed as mean+/-S.E.M. RESULTS: In the group of pregnant women, significantly higher serum levels of copper, ceruloplasmin and its oxidase activity were found than in the control group (p < 0.001). In both groups, a high correlation was found between these biochemical variables (r > or =0.905, p < 0.001). However, in the group of pregnant women the specific oxidase activity for ceruloplasmin (364.4+/-3.3 vs. 407.5+/-3.8 U/g) and the copper/ceruloplasmin ratio (2.82+/-0.03 vs. 3.19+/-0.04 microg/mg) were significantly lower than in the control group (p < 0.001). CONCLUSIONS: Although pregnancy accelerates the rate of ceruloplasmin protein synthesis and release with an increase of serum copper, the decrease in specific oxidase activity of circulating ceruloplasmin would be an indicator of the degree of depletion of the mother's copper deposits in order to deal with the foetus' needs.     

超声评价新生儿胼胝体发育及影响因素

目的通过颅脑超声监测胼胝体的生长率,分析新生儿胼胝体发育的影响因素,为早期评价和治疗脑发育性疾病提供依据。 方法选择2016年4月至12月就诊于兰州大学第二医院新生儿重症监护室（NICU）的97例新生儿,其中,早产儿54例（27~34周）,足月儿43例。所有新生儿于出生后0~6周每周行颅脑超声检查并测量胼胝体矢状长度,通过独立样本t检验比较早产儿、足月儿出生后0~6周胼胝体生长率。采用Spearman相关分析孕周、新生儿出生体质量与胼胝体生长率之间的关系。 结果（1）新生儿出生时胼胝体矢状长度与孕周、出生体质量成正相关（r=0.57、0.58）;（2）早产儿出生后0周、2周、3周、4周、5周、6周胼胝体长度均低于足月儿,差异均有统计学意义（t=6.22、6.51、7.81、8.87、10.25、11.64,P均<0.001）;（3）早产儿、足月儿出生后0~2周胼胝体生长率比较,差异无统计学意义（P>0.05）,出生后2~6周每周早产儿胼胝体生长率均低于足月儿,差异均有统计学意义（t=13.91、14.76、13.85、12.21,P均<0.001）。 结论新生儿胼胝体的发育与孕周、出生体质量有关;颅脑超声能实时动态监测胼胝体的生长发育。     

Hypoxic-ischemic encephalopathy and plasma beta-endorphin

In an attempt to determine whether hypoxic-ischemic encephalopathy in and of itself or its associated pathologic conditions lead to increased concentrations of plasma beta-endorphin (beta-ED), measurements were made in three groups of term infants. Group 1 (control) consisted of 8 infants with a mean gestation of 38.6 +/- (SE) 0.4 weeks, a mean birth weight of 3,420 +/- 150 g, and a mean postnatal age of 1.4 +/- 0.7 days. Group 2 consisted of 10 infants with a mean gestational age, birth weight and postnatal age of 40.1 +/- 0.5 weeks, 3,310 +/- 80 g and 3,9 +/- 1.1 days, and group 3 included 6 infants with a mean gestational age, birth weight and postnatal age of 40.4 +/- 1 weeks, 3,650 +/- 310 g, and 2.8 +/- 1 days, respectively. The group 2 and 3 infants suffered clinical and neurological evidence of hypoxic-ischemic brain injury from perinatal asphyxia; however, the infants in group 2 suffered additional problems such as meconium aspiration, persistent fetal circulation with ongoing hypoxemia as measured by transcutaneous or umbilical arterial oxygen monitoring. The group 3 infants were normoxemic after resuscitation. The mean plasma beta-ED concentrations were 19 +/- (SE) 2.7, 103 +/- 35.7 and 25 +/- 4.5 pg/ml in groups 1, 2 and 3, respectively. A significant elevation of plasma beta-ED concentration was observed in group 2 when compared to groups 1 and 3. The association of increased plasma beta-ED concentration in infants with hypoxic-ischemic encephalopathy associated with ongoing hypoxemia suggests that hypoxemia may act as a strong stimulus for plasma beta-ED release in term infants.     

Plasma beta-endorphin concentrations in neonates associated with acute stress

Plasma beta-endorphin concentrations were measured in two groups of neonates. The control group (group 1) consisted of 20 infants with a mean gestational age of 31.5 +/- 0.6 weeks and a mean birth weight of 1,720 +/- 135 g. Blood samples were collected at a mean postnatal age of 1.0 +/- 0.3 days. Group 2 consisted of 23 infants with clinical evidence of acute illness and associated significant stress who had a mean gestational age of 33.2 +/- 1.1 weeks and a mean birth weight of 2,075 +/- 225 g. Their blood samples were collected at a mean postnatal age of 3.4 +/- 1.3 days. The mean beta-endorphin concentration in group 1 was 27.8 +/- 6 pg/ml and 63.9 +/- 4.2 pg/ml in group 2 (p less than 0.05). No correlation was observed for gestation or birth weight and beta-endorphin concentrations in group 1; however, in group 2 a positive correlation was seen for gestational age and plasma beta-endorphin concentrations (r = 0.4411) suggesting an increased release of plasma beta-endorphin with increasing gestation when faced with significant clinical stress.     

Activities of copper,zinc-superoxide dismutase in erythrocytes and ceruloplasmin in serum in chronic ischemia of lower limbs

Cu,Zn-superoxide dismutase is an endogenous scavanger of superoxide radicals (O(2)(*-)) which also induce the synthesis of this enzyme. Ceruloplasmin is an antioxidant and acute-phase reactant. Changes in the synthesis of both enzymes are related to the metabolism of copper and zinc. Concentrations of copper and zinc were previously found to be increased in the serum and arterial wall of atherosclerotic subjects. The aim of this study was to investigate the Cu,Zn-superoxide dismutase activity in erythrocytes and ceruloplasmin activity in serum, and to measure serum concentrations of copper, zinc, and malonyldialdehyde in patients with moderate and critical chronic ischemia of the lower limbs. A group of 26 patients with chronic arterial occlusion of the lower limbs was divided into two groups depending on the degree of ischemia: moderate and critical. Cu,Zn-superoxide dismutase activity in erythrocytes was measured using the RANSOD kit, the serum ceruloplasmin oxidase activity was determined with o-dianisidine as a substrate. Copper and zinc concentrations in serum were determined by atomic absorption spectrometry. There was an increase in the ceruloplasmin activity and serum copper concentration in critical ischemia (194.4+/-51.94 U/l and 23.5+/-4.2 micromol/l, respectively) compared with moderate ischemia (139.1+/-34.9 U/l and 18.5+/-2.0 micromol/l, respectively). The Cu,Zn-superoxide dismutase activity in erythrocytes was higher in moderate ischemia (2,657+/-1,564 U/g hemoglobin) than in controls (1,205+/- 353 U/g hemoglobin), but not different from critical ischemia. There was a negative correlation for Cu,Zn-superoxide dismutase and ceruloplasmin (r=-0.60, P相似文献   

Umbilical cord and maternal blood leptin concentrations in intrauterine growth retardation.

Leptin, the ob gene product, plays an important role in the regulation of body fat mass and weight. In previous studies, it was demonstrated that leptin is detectable in human fetal cord blood as early as at 18 weeks of gestation and that serum leptin concentrations are significantly reduced in small gestational age newborns. In the present study, we investigated whether umbilical and maternal serum leptin concentrations correlate with intrauterine growth retardation (IUGR). In addition, we aimed to determine the relationships between leptin concentration in the maternal and cord blood. We studied 40 newborn infants (21 female and 19 male; gestational age, 38-42 weeks) and their mothers. Of the infants studied, 10 had IUGR. Serum leptin concentrations were measured by radioimmunoassay. All newborns had detectable leptin concentrations. Leptin concentrations were significantly lower in newborns with IUGR and in their mothers (n = 10; 3.53 +/- 1.42 ng/ml, 6.75 +/- 1.47 ng/ml, respectively) than in infants experiencing normal growth and their mothers (n = 30; 5.58 +/- 2.98 ng/ml, 9.85 +/- 6.50 ng/ml, respectively) (p < 0.01 for newborns, p < 0.05 for mothers). There was no significant correlation between umbilical leptin concentration and maternal leptin concentration (r = 0.229; p = 0.155) in all study groups but, significantly, a correlation was observed in the group with IUGR (r = 0.736; p = 0.015). There were no significant correlations between both umbilical and maternal leptin concentrations and parity, delivery type and gestational age. There was a correlation between umbilical leptin concentration and birth weight of newborns (r = 0.383; p = 0.015) but no correlation with body mass index (BMI) of the newborns (r = 0.034; p = 0.834). Maternal leptin concentrations correlated with maternal weight and BMI (r=0.606; p=0.000, r=0.535; p=0.000, respectively). There was no correlation between maternal leptin concentrations and birth weight of the newborns (r=0.179; p=0.269) and with BMI of the newborns (r = 0.146; p = 0.367). There was no gender difference in leptin concentrations in the newborns (n=21; 5.50 +/- 3.37 ng/ml, for females; n = 19; 4.58 +/- 1.98 ng/ml for males) (p = 0.296). In summary, we have shown that IUGR is associated with a decreased leptin concentration in newborns and their mothers. The association between umbilical serum leptin and birth weight in this and other studies suggests a pivotal role of fetal leptin in regulating fetal growth and development.     

Plasma brain natriuretic peptide as a predictor of haemodynamically significant patent ductus arteriosus in preterm infants

Patent ductus arteriosus (PDA) is an important cause of morbidity in extremely preterm infants. As increased plasma brain natriuretic peptide (BNP) is a common feature of adult cardiac disease, we investigated the value of plasma BNP concentration as a predictor of haemodynamically significant PDA in very preterm infants. We studied 18 preterm infants (12 male) of median gestational age 30 weeks (range 24-34), median birth weight 1.46 kg (0.54-2.13) and 11 healthy term controls. Plasma BNP levels were measured by double-antibody radioimmunoassay on days 3, 5 and 7 of life, and an echocardiogram was performed on day 7. Six infants of median gestation 26 weeks (26-30), median birth weight 0.92 kg (0.54-1.04) had PDA proven by echocardiography on day 7. BNP concentrations (pg/ml) on day 3 were significantly higher in these infants than in the remaining twelve [median 2012 (786-2759) versus 42 (7-704), P<0.001]. In four infants PDA was treated successfully (one surgically, three with non-steroidal anti-inflammatory drugs). Two had haemodynamically insignificant closing ducts. In these infants with therapeutic or spontaneous resolution of a PDA, plasma BNP fell to normal values [median after treatment 9 pg/ml (8-27)]. Early measurement of plasma BNP in the first few days of life is a useful method for predicting those preterm infants who may require intervention for PDA.     

Growth retardation in fetuses with gastroschisis

This study was designed to determine the prevalence of intrauterine growth restriction in neonates with gastroschisis and to evaluate the accuracy of the ultrasonographic diagnosis of intrauterine growth restriction. Birth weight and gestational age were determined for 46 infants diagnosed prenatally as having gastroschisis. Biometric data were analysed for the 30 pregnancies in which an examination was conducted within 1 week of delivery. Fetal growth parameters were compared with norms for gestational age. The prevalence of intrauterine growth restriction in the entire study group was 24% with a mean birth weight of 2401 +/- 508 g. Ultrasonographic estimated fetal weight was significantly less than birth weight (mean, 2079 +/- 508 g versus 2331 +/- 512 g, respectively; P < 0.0001). Intrauterine growth restriction was predicted in 43% of infants but was present in only 23%. The percentage difference between measured abdominal circumference and gestational age norm was significantly more than for biparietal diameter and for femur length (P < 0.001). Of the three biometric measures, only the difference between measured abdominal circumference and gestational age norms and the difference between estimated fetal weight and birth weight showed a significant correlation. Both abdominal circumference and femur length correlated with the difference between estimated fetal weight and birth weight. We conclude that the prevalence of intrauterine growth restriction is increased in infants with gastroschisis but is overestimated with prenatal ultrasonography, primarily because of smaller than average abdominal circumference measurements.     

Free thyroxin measured in dried blood spots from normal, low-birth-weight, and hypothyroid neonates.

We have adapted a new radioimmunoassay for free thyroxin (FT4) measurement in dried blood spots for use in neonatal screening for hypothyroidism. The method is easy, fast, and cheap. Within-assay and between-assay CVs are respectively 9.6% and 13.2%. In 997 neonates three days postpartum with normal thyrotropin concentrations, the mean FT4 concentration was 27.2 pmol/L (SD 7.3 pmol/L). There was no significant difference in mean FT4 concentration between boys and girls. FT4 concentrations increased linearly with birth weight or with gestational age, as expressed by multiple linear regression: FT4 (pmol/L) = 0.0016 birth weight (g) + 0.6931 gestational age (weeks) - 4.8772. Only gestational age significantly affected the FT4 value. For five hypothyroid infants tested on day three postpartum, FT4 values were all below the 1st percentile of values from healthy neonates. Thus, when the neonatal concentration of thyrotropin is above normal, FT4 measured in the same sample can provide a reliable earlier diagnosis of hypothyroidism.     

Gestational weight gain and pregnancy outcomes in 481 obese glucose-tolerant women

OBJECTIVE: To investigate the effect of gestational weight gain in obese glucose-tolerant women. RESEARCH DESIGN AND METHODS: We performed a historical cohort study of 481 women with prepregnancy BMI > or = 30 kg/m2 and a normal 2-h 75-g oral glucose tolerance test (OGTT) during the third trimester (according to World Health Organization criteria). Data on OGTT results and clinical outcomes were collected from medical records. Four groups were defined according to weight gain: group 1, <5.0 kg (n = 93); group 2, 5.0-9.9 kg (n = 134); group 3, 10.0-14.9 kg (n = 132); and group 4, > or = 15.0 kg (n = 122). RESULTS: Birth weight increased significantly with increasing weight gain (mean grams +/- SD): group 1, 3,456 +/- 620; group 2, 3,624 +/- 675; group 3, 3,757 +/- 582; and group 4, 3,784 +/- 597 (P < 0.001). The birth weight in group 1 was similar to that of the background population of primarily normal-weight women (3,478 g). In multivariate analyses, increasing weight gain was associated with significantly higher rates of hypertension (OR 4.8 [95% CI for group 4 vs. group 1: 1.7-13.1]), cesarean section (3.5 [1.6-7.8]), induction of labor (3.7 [1.7-8.0]), and large-for-gestational-age infants (4.7 [2.0-11.0]). There was no difference in rates of small-for-gestational-age infants. Significant predictors for birth weight (determined by multiple linear regression) were gestational weight gain, 2-h OGTT result, pre-gestational BMI, maternal age, gestational age, and smoking. CONCLUSIONS: Increasing weight gain in obese women is associated with increasing pregnancy complications. Our data suggest that minimal gestational weight gain might normalize birth weight. Prospective studies should be performed to clarify the safety of recommending limited gestational weight gain.     

Accuracy of sonographically estimated fetal weight in 840 women with different pregnancy complications prior to induction of labor.

OBJECTIVES: To evaluate the accuracy of sonographically estimated fetal weight (EFW) shortly before induction of labor in the presence of different pregnancy complications, and to define possible variables affecting it. METHODS: The study sample consisted of 840 women with singleton pregnancies and cephalic presentation who were admitted to our unit for induction of labor between January 1999 and December 2000. All underwent detailed ultrasound assessment for EFW, amniotic fluid index, biophysical profile and placental location. Indications included previous Cesarean section, postdate pregnancy, pregnancy-induced hypertension, diabetic pregnancy, suspected large-for-gestational age (LGA) infants, suspected fetal growth restriction (FGR), oligohydramnios, decreased fetal movements, premature rupture of membranes at or before term. EFW was calculated after measuring fetal abdominal circumference and femur length. The EFW was compared with the weight at delivery, 1-3 days later. RESULTS: There was a high correlation between EFW and birth weight (R(2) = 0.775, P < 0.001). The mean birth weight was 3207 +/- 561 g, and mean absolute weight difference was 227 +/- 197 g; (absolute range, 0-1700 g; actual range, - 986 to + 1700 g). The mean weight difference was significantly different between the patients with LGA infants, FGR infants and preterm premature rupture of membranes (PPROM) (- 110 +/- 281 g, + 113 +/- 195 g and + 115 +/- 307 g, respectively, P < 0.01). Stepwise linear regression analysis of the effects of maternal and pregnancy characteristics on the weight difference yielded lower gestational age, higher birth weight, anterior placenta, higher gravidity, and younger maternal age as independent and significant variables associated with greater actual weight difference inaccuracy (R(2) = 0.099, P < 0.001), and higher birth weight as the only independent and significant variable associated with greater absolute weight difference (R(2) = 0.09, P = 0.018). CONCLUSIONS: The sonographic EFW is highly correlated with birth weight. However, clinicians should be aware of the risk of overestimation in pregnancies with suspected LGA and underestimation in pregnancies with PPROM and suspected FGR.     

早产儿血小板参数动态变化及其与并发症的关系

目的探讨早产儿血小板参数的动态变化及其与早产儿并发症的关系。方法对96例早产儿于出生24h内和生后1周进行血小板参数检测。结果早产儿胎龄越小、出生体重越低,出生24h内PLT越低、MPV和PDW越大。无窒息及无并发症早产儿PLT、MPV及PDW生后1周较出生24h内有不同程度升高(P<0.05或0·01)。出生24h内,IVH和RDS组PLT明显低于无并发症组(P<0.01和0·05),IVH组MPV明显大于无并发症组(P<0.01);生后1周,窒息组PLT明显低于无窒息组(P<0.01),MPV、PDW明显大于无窒息组(P<0.01和0·05),低体温和感染组PLT明显低于无并发症组(P<0.05和0·01),感染组MPV明显大于无并发症组(P<0.05)。结论早产儿血小板参数与胎龄、出生体重及日龄有关;出生时合并窒息及早产儿并发症与血小板参数密切相关。