The Apgar score revisited: influence of gestational age

We tested the hypothesis that Apgar scores are in part related to the newborn infant's level of maturity. Seventy-three pregnant women with normal fetuses of gestational age 22 to 42 weeks were studied. Fetal well-being was documented by a prospectively designed recording of pregnancy history, labor complications, and birth outcome, including cord blood pH and base deficit measurements. The 1- and 5-minute Apgar scores were directly related to gestational age. Respiratory efforts, muscle tone, and reflex were the major determinants for a decreasing Apgar score with declining gestational age. We conclude that the 1- and 5-minute Apgar scores are influenced by the infant's level of maturity and that our data may be useful in evaluating the true value of Apgar scores in assessing the fetal and neonatal condition of low birth weight infants.     

Evaluation of umbilical cord pH and its relationship with Apgar score in term newborn infants

The value of the Apgar score as an index of birth asphyxia has been recently questioned. The purpose of the present study is to evaluate the relationship between cord blood pH and Apgar score in term newborn infants.A cross-sectional study involving 76 term newborn infants was performed from March through September 1995 at the Obstetric Unit of Hospital de Clínicas de Porto Alegre. The blood samples were obtained from umbilical cord artery and vein at the moment of delivery. Infants were divided in three different groups according to the Apgar score: Group A (n=60): >or=7 at one and five minutes; Group B (n=13): < 7 at one minute and >or=7 at five minutes; Group C (n=3): < 7 at one and five minutes. The frequency of acidemia in Group A was 18.3% (11 newborn infants) considering arterial pH < 7.20 and 5% considering arterial pH or= 7.20 and nine (56.2%) had arterial pH > 7.10. None of the newborn infants in Group C had arterial pH > 7.10. The sensitivity and specificity values for Apgar score less than 7 at one minute for detection of fetal acidemia were, respectively, 54.1% and 94.1%. This study confirms a poor correlation between Apgar score and umbilical blood cord pH, even in a term newborn, and emphasizes the importance of obtaining umbilical cord pH to consider the diagnosis of perinatal asphyxia.     

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

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

脐动脉血pH值在新生儿窒息中的意义和价值

目的：由于Apgar评分的局限性,有可能造成新生儿窒息的误诊和漏诊,为弥补其不足,探讨脐动脉血pH值在新生儿窒息诊治中的意义和价值。方法：对经胎心电子监护异常的单胎足月新生儿140例,出生后立即采集脐动脉血进行pH值测定,同时给予生后1 min及5 min Apgar评分,对于62例1 min Apgar≤7分者,窒息复苏后立即转入儿科病房观察治疗,进行血清肌钙蛋白Ⅰ（CTnI）和脏器损伤指标的检测,并进行统计学分析。结果：脐动脉血pH值与出生后1 min和5 min Apgar评分呈正相关(r=0.513和0.478,均P＜0.01),Apgar评分愈低,脐动脉血pH值愈低,各分值组之间差异有显著性（P＜0.01）。出生后1 min及5 min Apgar评分与血清CTnI呈负相关（r=-0.614和-0.569,均P＜0.01）。脐动脉血pH值＞7.20,7.00~7.20,＜7.00相对应的血清CTnI值分别为（31.82±8.63）ng/L,（53.24±11.18）ng/L和（79.36±18.51）ng/L,随脐动脉血pH值的降低, 血清CTnI值明显升高(P＜0.01)。脏器损伤的发生率随Apgar评分的降低而升高（P＜0.05）,两者呈负相关(r=-0.548和-0.496,均P＜0.01)。脐动脉血pH值＞7.2,7.00~7.20,＜7.00相应的脏器损伤发生率分别为36.4％,60.0％及83.3％,脏器损伤的发生率随脐动脉血pH值的降低而升高（P＜0.05）, 两者呈负相关(r=-0.578,P＜0.05)。结论：①脐动脉血pH值和Apgar评分具有相关性,可作为诊断新生儿窒息的敏感指标之一,与Apgar评分相互补充。②脐动脉血pH值对于诊断新生儿窒息,判断病情轻重及预后评估具有重要临床意义。［中国当代儿科杂志,2009,11（7）：521-524］     

Glucose replacement to euglycemia causes hypoxia, acidosis, and decreased insulin secretion in fetal sheep with intrauterine growth restriction

Nutritional interventions for intrauterine growth restriction (IUGR) have raised concerns for fetal toxicity, the mechanisms of which are unknown. Most of these attempts did not aim to normalize fetal metabolic conditions. Therefore, we used a model of IUGR to determine whether normalization of fetal hypoglycemia for 2 wks would be tolerated and increase insulin concentrations and pancreatic beta-cell mass. IUGR fetuses received either a direct saline infusion (Sal, the control group) or a 30% dextrose infusion (Glu) to normalize glucose concentrations. Neither insulin concentrations (0.11 +/- 0.01 Glu vs. 0.10 +/- 0.01 ng/mL Sal) nor beta-cell mass (65.2 +/- 10.3 Glu vs. 74.7 +/- 18.4 mg Sal) changed. Glucose stimulated insulin secretion (GSIS) was lower in the Glu group. Glu fetuses became progressively more hypoxic: O2 content 1.4 +/- 0.5 Glu vs. 2.7 +/- 0.4 mM Sal, p < 0.05. Partial pressure of carbon dioxide (Paco2) (53.6 +/- 0.8 Glu vs. 51.6 +/- 0.8 Sal, p < 0.05) and lactate (7.74 +/- 3.82 Glu vs. 2.47 +/- 0.55 mM Sal, p < 0.0001) were greater and pH lower (7.275 +/- 0.071 Glu vs. 7.354 +/- 0.003 Sal, p < 0.01) in the Glu group. We conclude that correction of fetal hypoglycemia is not well tolerated and fails to increase insulin concentrations or beta-cell mass in IUGR fetuses.     

Umbilical cord blood erythroblast count as an index of intrauterine hypoxia.

The relation of umbilical cord blood arterial pH, Apgar score, leucocyte count, and erythroblast count at delivery with the diagnosis of fetal distress in labour was studied prospectively in three groups of singleton pregnancies delivering at term vaginally (55 infants), by elective caesarean section (39 infants), or by emergency caesarean section for abnormal intrapartum fetal heart rate patterns (55 infants). In the emergency caesarean section group the umbilical cord blood arterial pH was significantly lower and the leucocyte and erythroblast counts were higher than in the elective caesarean section group. Comparison of the emergency caesarean section and spontaneous vaginal delivery groups showed significant differences for pH and erythroblast count, but not for leucocyte count. In the spontaneous vaginal delivery group erythroblastosis was associated with umbilical cord blood pH, whereas leucocytosis was associated with the length of labour. The five minute Apgar score was > or = 7 in all infants. This study suggests that leucocytosis is a non-specific response of the fetus to labour, whereas erythroblastosis reflects fetal tissue hypoxia.     

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

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

Circulating S100beta protein is increased in intrauterine growth-retarded fetuses.

To determine whether S100beta, an acidic calcium-binding protein previously demonstrated as a reliable indicator of a brain lesion, could be helpful in the detection of brain distress in intrauterine growth-retarded (IUGR) fetuses, we studied, by a case-control study, the correlation between S100B protein and the degree of fetoplacental blood flow impairment. Maternal and umbilical blood samples and placental tissue specimens were collected at delivery from IUGR pregnancies with normal (n = 10) or abnormal (n = 10) umbilical artery Doppler findings and from 40 uncomplicated pregnancies. S100beta protein levels were measured by means of a specific RIA, and flow velocimetry waveforms were recorded from uterine, umbilical, and fetal middle cerebral arteries. Overall mean S100beta proteins in umbilical plasma levels were higher (p < 0.05) in IUGR patients (121.8 +/- 70.4 fmol/mL) than in control patients (54.7 +/- 21.9 fmol/mL). IUGR fetuses with redistribution of blood flow showed the higher concentration of the protein (163.7 +/- 55.2 fmol/mL). Fetal S100beta concentrations correlated with middle cerebral artery pulsatility index (r = -0.536, p < 0.03) and with umbilical artery pulsatility index to middle cerebral artery pulsatility index ratio (r = 0.469, p < 0.03). No difference in the localization or intensity of S100beta staining in the placental tissues or cord between uncomplicated and IUGR pregnancies was found. This study provides evidence that circulating S100beta protein is increased in IUGR fetuses and correlates with cerebral hemodynamics, suggesting that it may represent an index of cerebral cell damage in the perinatal period.     

Correlation between Umbilical Cord pH and Apgar Score in High-Risk Pregnancy

Objective

The Apgar score as a proven useful tool for rapid assessment of the neonate is often poorly correlated with other indicators of intrapartum neonatal well-being. This study was carried out to determine the correlation between umbilical cord pH and Apgar score in high-risk pregnancies.

Methods

This is a prospective cross-sectional, analytic study performed on 96 mother-fetal pairs during 2004-2005 at Shahid Yahyanejad Hospital, which is affiliated to Babol University of Medical Sciences. Apgar score at 1 and 5 minutes after birth was taken and an umbilical cord blood gas analysis was done immediately after birth in both groups. Mothers came with a labor pain and were divided into high-risk and low risk if they have had any perinatal risk factors. Other data like gestational age, birth weight, need for resuscitation and admission to the newborn ward or Neonatal Intensive Care Unit was gathered by a questionnaire for comparison between the two groups. P-value less than 0.05 was considered being significant.

Findings

The gestational age and birth weight were the same in high-risk and low risk mothers. Mean umbilical artery blood pH in high-risk mothers was significantly lower than in low risk mothers (P=0.004). Mean Apgar scores at 1 and 5 minutes were significantly lower in high-risk mothers than in low risk mothers (P<0.05). According to the Kendal correlation coefficient there was no significant correlation between Apgar score at 1 and 5 minutes and umbilical cord pH in low risk group (r=0.212, P=0.1). But in high-risk group there was significant correlation between Apgar score at 1^st and 5^th minute and the umbilical cord pH (r=0.01, P=0.036 and r=0.176, P=0.146, respectively).

Conclusion

Combination of Apgar score and umbilical cord pH measurement in high-risk pregnant mother could better detect jeopardized baby.     

Periodic spectral components of fetal heart rate variability reflect the changes in cord arterial base deficit values: a preliminary report

Fetal distress changes the function of the autonomic nervous system. These changes are reflected in the fetal heart rate and can be quantified with power spectrum analysis of heart rate variability. The purpose of this study was to find out whether spectral components of fetal heart rate variability (FHRV) during labor are associated with fetal cord arterial base deficit values at birth. The association between FHRV and umbilical cord arterial base deficit was studied in 14 singleton fetuses with normal pregnancy at 35–40 weeks of gestation. Fetal ECG was recorded by scalp-electrode using a STAN^® Fetal ECG monitor (Cinventa Ab, Mölndal, Sweden). FHRV was quantified by computing Fast-Fourier-transformed heart rate (HR) spectra at three frequency bands: low-frequency (LF) 0.03–0.07 Hz, mid-frequency (MF) 0.07–0.13 Hz and high-frequency (HF) 0.13–1.0 Hz. We found that total FHRV and MF FHRV were lower in fetuses with cord arterial base deficit 8 to 12 mmol/L in comparison to the fetuses with normal cord arterial base deficit value (P=0.02 and P=0.01, respectively). A linear correlation was found between the spectral densities and the cord arterial base deficit values (r=0.4 and r=0.6, respectively). We conclude that the results suggest changes in the autonomic nervous cardiac control in fetuses with cord arterial base deficit between 8 to 12 mmol/L. The clinical applicability of our observations on FHRV in predicting fetal distress remains to be further studied.     

Urinary and plasma epidermal growth factor levels are decreased in neonates with intrauterine growth retardation and in their mothers.

Epidermal growth factor (EGF) concentrations in urine and plasma samples collected from pregnant women and neonates were measured by RIA. The EGF concentration of the first voided urine was higher in appropriate-for-date (AFD) neonates (33.9 +/- 23.0 ng/mg creatinine) than in those with intrauterine growth retardation (IUGR; 23.5 +/- 7.7 ng/mg creatinine, p less than 0.05) and heavy-for-date (19.8 +/- 5.2 ng/mg creatinine, p less than 0.05) neonates. The urinary EGF concentration of pregnant women showed no marked changes throughout pregnancy. Urinary EGF concentrations of women with AFD fetuses (45.9 +/- 31.2 ng/mg creatinine) did not differ significantly from those of women with diabetes (39.9 +/- 26.8 ng/mg creatinine) or women with multiple fetuses (44.6 +/- 30.6 ng/mg creatinine). However, women with IUGR fetuses showed lower urinary EGF concentrations (13.8 +/- 7.4 ng/mg creatinine, p less than 0.05) than women with AFD fetuses. Maternal and fetal platelet-poor plasma EGF concentrations at delivery were lower in the IUGR group (mother: 2.62 +/- 0.38 ng/ml, fetus: 2.16 +/- 0.07 ng/ml, respectively, p less than 0.05 and p less than 0.005) than in the AFD group (mother: 3.34 +/- 0.64 ng/ml, fetus: 3.24 +/- 0.93 ng/ml). In the IUGR group, the EGF concentration in fetal blood was always lower than that in maternal blood (p less than 0.05), although the AFD groups showed no such difference. These data suggest that EGF levels are closely related to fetal growth.     

新生儿脐血pH和BE影响因素的研究

目的通过大样本收集新生儿脐血血气,研究脐血血气统计学参考值范围与不同影响因素的相关关系。方法选择2012年5～11月广东省妇幼保健院和新会妇幼保健院产科出生的新生儿进行前瞻性研究,选取其中1rainApgar评分〉7分者的脐血血气结果进行统计分析,了解正常新生儿脐血血气的统计学参考值范围;重点分析影响新生儿脐血pH和BE的因素。结果2000例新生儿中,1min Apgar评分≤7分11例,〉7分1989例,低Apgar评分组pH〈7．2的比例为45．5％,正常Apgar评分组pH〈7．2的比例为3．5％,差异有统计学意义（P〈0．001）;1800例足月单胎、体重适于或大于胎龄新生儿中,1794例1min Apgar评分〉7分者脐血pH和BE的统计学参考值范围分别是7．34±0．14（X±1．96S）和-3．53±6．57（X±1．96s）。单因素分析显示,宫内窘迫组、妊娠期并发症组pH值均低于对照组,剖宫产组pH和BE值均高于阴道分娩组,脐带绕颈组pH值降低,双胎组BE值高于单胎组;羊水性状对pH、BE值均无影响。多因素分析显示,宫内窘迫、分娩方式均对脐血血气有影响。结论足月单胎、体重适于或大于胎龄新生儿中,1min Apgar评分〉7分者脐血pH值和BE值的统计学参考值范围分别是7．34±0．14和-3．53±6．57;Apgar评分与脐血血气分析具有一致性,但单独使用Apgar评分诊断早产儿窒息可能会增加窒息的误诊率;宫内窘迫可能会增加新生儿酸中毒的发生率,不同分娩方式对脐血血气pH、BE值均有影响。     

Plasma ionized magnesium levels in neonatal respiratory distress syndrome

Measurement of ionized magnesium (IMg) provides an accurate assessment of the free form of Mg, which is the physiologically active form and is most reflective of the biologically active and not easily measurable intracellular Mg fraction. Plasma levels of IMg were measured by ion-selective electrode method in premature newborns with respiratory distress syndrome (RDS), and relationships and correlations between IMg levels and various demographic, prognostic and laboratory characteristics were investigated by comparing the premature newborns with (study group; n = 19) and without RDS (control group; n = 20) in the present study. The values of the postnatal arterial pH and base excess and plasma IMg levels were significantly different between the study and control groups, and the number of newborns with any morbidity was significantly higher in the study group. Within the study group there were significant negative correlations between the plasma IMg levels and the values of the umbilical cord arterial pH (r = -0.621, p = 0.005) and base excess (r = -0.746, p = 0.001), and the value of the postnatal arterial base excess (r = -0.585, p = 0.008). The newborns who died later had higher plasma IMg levels than those who survived (0.89 +/- 0.45 vs. 0.63 +/- 0.24 mmol/l, p = 0.026). These findings suggest that increase of plasma IMg may be due to extracellular movement of Mg, which is a principally intracellular ion, as a result of acidosis, hypoxia and probable cellular injury during the early course of RDS. The exact pathophysiological mechanism responsible for IMg increase, and whether determination of plasma IMg level, including umbilical cord blood IMg measurement, can be used as an early or predictive indicator of RDS in the diagnosis remain to be determined in further large-scale studies.     

Effect of maternal oxygen inhalation on the fetus with growth retardation

Decreased nutrient and oxygen transfer to the fetus accounts for fetal growth retardation in pregnancies complicated by severe uteroplacental insufficiency. A model of uteroplacental insufficiency was produced by ligation of the uterine artery of one horn in pregnant rats at 17 days of gestation. The pregnant rats were assigned to environmental chambers containing a gas mixture of either an increased fractional inspired oxygen concentration of 0.40 (O2) or room air from day 17 through 21 of gestation. Supplemental oxygen inhalation resulted in increased survival of the fetuses from the ligated horn [34 +/- 6% in intrauterine growth retardation (IUGR)-room air versus 57 +/- 8% in IUGR-O2] and an increase in fetal weight, expressed as a percentage of nonligated appropriate for gestational age control littermates (67 +/- 2% in IUGR-room air versus 74 +/- 2% in IUGR-O2). A role for hypoxia in the suppression of fatty acid synthesis in IUGR fetal tissues had been postulated; however, maternal oxygen inhalation did not result in any increase in fatty acid content or specific activity in liver, lung, or carcass of IUGR fetuses. These data indicate that supplemental maternal oxygen inhalation improves survival and growth of fetuses compromised by uteroplacental insufficiency, but it has no apparent effect on lipogenesis at term.     

The effect of umbilical venous constriction on placental development, cord length and perinatal outcome

BACKGROUND: Umbilical vein constriction at the fetal abdominal inlet is a common finding after week 13, when the period of umbilical herniation is brought to an end. AIMS: To test the hypothesis that a constricting umbilical ring within physiological ranges affects fetal hemodynamics by either pooling blood in the placenta or restricting nutrient transfer to the fetus and thus shift the birthweight/placental weight (BW/PW) ratio. A constriction could also cause pressure changes and elongation of the cord and possibly be a disadvantage during labour. STUDY DESIGN: Cross-sectional. SUBJECTS: 359 Low-risk singleton pregnancies at 13-40 weeks of gestation. OUTCOME MEASURES: Standard deviation score (z-score) and regression analysis were used to determine the effect of umbilical vein constriction (expressed by increased blood velocity) on birthweight/placental weight ratio (BW/PW), cord length, Apgar score and emergency delivery due to fetal distress. RESULTS: Umbilical venous constriction had a mild but significant effect on BW/PW in male (p=0.018) but not in female fetuses. Increased constriction was also associated with increased length of the cord but only in female fetuses (p=0.019). Cord length was positively related to birthweight and placental weight, but an increased length of the cord was also associated with decreasing BW/PW ratio for the male fetuses only (p=0.044). Increasing degree of venous constriction was associated with Apgar score < or =7 at 1 (p=0.009) but not at 5 min after birth and was not associated with emergency delivery. CONCLUSION: Physiological umbilical venous constriction exerts a mild but significant gender-specific hemodynamic impact on intrauterine development.     

Neonatal hypertriglyceridemia: a new index of antepartum-intrapartum fetal stress?

The 95th percentile value of cord serum triglyceride concentration in 82 consecutively live born infants was found to be 0.79 mmol/l. This level was arbitrarily used to define neonatal hypertriglyceridemia. A comparison between 78 normotriglyceridemic and 61 hypertriglyceridemic newborn infants showed a significant association between elevated cord serum triglyceride concentration and insufficiency of the placenta, fetal bradycardia, meconium-stained amniotic fluid and one-minute Apgar score less than or equal to 7. A significantly (p less than 0.001) greater number of infants with one or several of these four factors, indicating antepartum and/or intrapartum fetal stress were found to be hypertriglyceridemic at birth. This finding suggests that estimation of cord serum triglyceride which is easy and inexpensive might be of value for a more complete evaluation of the newborn infant, and can serve as a supplement to the Apgar Score system.     

Early postnatal changes in the perfusion index in term newborns with subclinical chorioamnionitis

BACKGROUND: Chorioamnionitis (HCA) in term newborns is often subclinical and associated with neonatal morbidity and mortality. OBJECTIVE: To assess the value of the pulse oximetry perfusion index (PI) in the early prediction of subclinical HCA in term newborns. METHODS: PI cut-off values were first identified in 51 term newborns with HCA and 115 matched controls, retrospectively categorised on the basis of placental histology (study phase 1). The PI thresholds obtained were subsequently tested on an unselected case series of 329 prospectively recruited, term newborns (study phase 2). PI was evaluated during the first five minutes after delivery. Initial illness severity and short term clinical outcomes were determined. RESULTS: In study phase 1, newborns with HCA had lower PI one and five minutes (p<0.0001) after delivery, lower one minute Apgar score (p = 0.017), lower cord blood base excess (p = 0.0001), together with higher rates of admission to neonatal intensive care unit (p = 0.0001) and endotracheal intubation (p = 0.017), and higher SNAP-PE (p<0.0001) and NTISS (p<0.0001) scores than those without HCA. In the prospective validation phase of the study, the PI cut-off values generated (one minute < or =1.74, five minutes < or =2.18) showed 100% sensitivity, 99.4% specificity, 93.7% positive predictive value, and 100% negative predictive value in identifying subclinical HCA. Early identification of HCA was associated with a decreased rate of admission to intensive care (p = 0.012), as well as lower initial illness severity (p< or =0.0001) and therapeutic intensity (p = 0.0006) than the newborns with HCA in phase 1. CONCLUSION: These findings suggest that early PI monitoring is helpful in identifying HCA in term newborns.     

Fetal plasma leptin concentrations: relationship with different intrauterine growth patterns from 19 weeks to term

The relationship between in utero fetal growth and fetal leptin concentrations was investigated between 19 and 41 wk in 40 normal (appropriate for gestational age, AGA) fetuses, in 25 intrauterine growth-restricted (IUGR) fetuses, and in 18 fetuses from gestational diabetic mothers (GDM), representing different intrauterine growth patterns. Umbilical venous plasma leptin concentrations were determined at the time of either in utero fetal blood sampling or delivery. Plasma leptin was measurable as early as 19 wk of gestation. A significant difference was observed between umbilical venous and arterial plasma leptin concentrations (0.6+/-0.6 ng/mL; p<0.01). In AGA and in IUGR fetuses, significant positive relationships were found between fetal leptin concentrations and both gestational age (p<0.001) and fetal weight (p<0.001). Leptin concentrations were significantly higher in AGA than IUGR only after 34 wk (p<0.05), but leptin per kilogram fetal weight (leptin/kg) was not significantly different. In IUGR with abnormal umbilical arterial Doppler velocimetry and fetal heart rate, leptin/kg significantly higher than in IUGR with normal biophysical and biochemical parameters was found (p<0.05). Both circulating plasma leptin and leptin/kg were significantly higher in GDM than in normal fetuses (p<0.001) and correlated with abdominal fat mass measured by ultrasound. No gender differences were observed in any group of fetuses. These findings indicate a clear relationship between fetal leptin concentrations and fetal fat mass. Data in severe IUGR suggest the presence of increased leptin concentrations associated with in utero signs of fetal distress.     

重度新生儿呼吸窘迫综合征死亡危险因素分析

目的探讨重度新生儿呼吸窘迫综合征（respiratory distress syndrome,RDS）导致死亡的主要危险因素。方法回顾性分析2010年1月至2011年12月我院NICU诊断为重度RDS的66例早产儿的病例资料。按患儿结局分为死亡组和存活组进行分析。结果重度RDS死亡24例,病死率36．36％。死亡组患儿机械通气时间、碱剩余中位数、pH最小值、PaO2／FiO2最小值、平均胎龄、平均出生体重、1min Apgar评分、5min Apgar评分均低于存活组（P均〈0．05）。死亡组机械通气FiO2〉60％时间中位数、合并宫内窘迫比例、多胎比例、新生儿急性生理学评分围生期补充-Ⅱ（sore for neonatal acute physiology perinatal extension versionⅡ,SNAPPE-Ⅱ）均高于存活组（P均〈0．05）,两组机械通气并发症比较差异无统计学意义（P〉0．05）。对相关变量行Logistic回归分析,重度RDS死亡独立危险因素为出生体重、1minApgar评分和SNAPPE-Ⅱ评分,OR值为0．990、0．141和1．240。对SNAPPE—II评分进行受试者工作特征曲线分析,曲线下面积为0．86,与0．5相比差异有统计学意义（P=0．000）。分界点SNAPPE-Ⅱ评分=24．50时对应的正确预测指数最大（Youden指数=0．70）。结论重度RDS死亡独立危险因素为出生体重、1minApgar评分和SNAPPE—Ⅱ评分;SNAPPE-Ⅱ评分对重度RDS死亡风险预测准确性中等,其为24．50时预测准确性最大。     

Fetal internal carotid and umbilical artery blood flow velocity waveforms as a measure of fetal well-being in intrauterine growth retardation

Maximal flow velocity waveforms were recorded on one occasion from the umbilical artery (UA) and fetal internal carotid artery (ICA) in 240 normal pregnancies and 44 cases of intrauterine growth retardation between 26 and 39 wk of gestation. In normal pregnancy the mean UA pulsatility index (PI) decreased from 1.14 (SD: +/- 0.13) at 26-27 wk of gestation to 0.78 (SD: +/- 0.15) at 38-39 wk. The corresponding decrease in ICA PI was from 1.63 (SD: +/- 0.19) to 1.31 (SD: +/- 0.21). Mean values of UA PI for normal pregnancies were linearly related to gestational age; for ICA PI this relation appeared to be quadratic. Normal limits according to age were constructed by estimated means +/- 2 SD. In intrauterine growth retardation, the UA PI was increased (greater than 2 SD) in 80% of cases, ICA PI was reduced (greater than 2 SD) in only 45%. The outcome of fetuses with intrauterine growth retardation, as expressed by fetal heart rate abnormality, Apgar score at 1 min, and umbilical cord pH, was significantly related to the UA PI but not to the ICA PI.