The very low birthweight infant: incidence and significance of low Apgar scores, "asphyxia," and morbidity. Findings at delivery

Cord blood gas determinations were made on arterial and venous blood from 78 babies weighing less than 2000 gm at birth, including 52 weighing 1500 gm or less. Correlations were made with Apgar scores and intrapartum events as well as with birthweight (BW) and gestational age (GA). Significant differences were seen between mean BW, GA, and Apgar scores for survivors versus nonsurvivors but only BW and GA were found to affect mortality. The incidence of low Apgar scores, which was high, was inversely related to BW and GA. Correlations between cord blood gases and Apgar scores were poor, most newborns showing normal gases irrespective of Apgar scores. The authors conclude that the term "asphyxia" is an overused explanation for low Apgar scores among very low birthweight babies; they believe it should be reserved for those depressed states proved to be associated with disturbed respiratory physiology.     

The association of hypotonia and depression in the term and near-term neonate with metabolic acidemia

AIMS: To determine the association of hypotonia and depression in neonates at or near term with metabolic acidemia at birth (umbilical arterial pH<7.0 and base excess <-12 mM). METHODS: This case-control study identified 87 infants without chromosomal or congenital abnormalities born at a single university hospital between 7/91 and 10/04 with hypotonia at birth requiring resuscitation and admission to the neonatal intensive care unit that had a cord gas at delivery. Controls were the subsequent delivery with a cord gas matched by gestational age. RESULTS: Cases and controls did not differ in gestational age (38.7+/-1.9, 38.6+/-1.9 weeks) or birth weight (3,066+/-664, 3,171+/-655 g, P=0.20). Cases were more likely to have a cord pH<7.0 [17 (20%) vs. 1 (1.1%), P=0.0001] and cord pH 7.0-7.1 [13 (14.9%) vs. 2 (2.3%), P=0.003]. Among the hypotonic infants, 31 (35.6%) also were depressed at birth with a 5-min Apgar <7. In the depressed subset of hypotonic neonates 14/31 (45%) had a pH<7.0. Of the 12 hypotonic neonates with seizures, 3 (25%) had pH<7.0. Multivariate analysis showed a significant association between neonatal hypotonia and hypoglycemia, umbilical arterial pH, and nucleated red blood cell count. CONCLUSIONS: Although metabolic acidemia is significantly associated with hypotonia at the time of birth, the majority of neonates with hypotonia and depression or seizures do not have objective evidence of asphyxia as measured by a cord gas at the time of delivery.     

Routine umbilical cord blood gas determinations?

Between 1986 and 1988, 1924 term nulliparous patients with spontaneous onset of labor were studied to assess the importance of obtaining umbilical cord blood gas levels on all deliveries. The umbilical cord arterial and venous pH values (expressed as mean +/- 2 SD) were 7.24 +/- 0.14 (n = 1694) and 7.32 +/- 0.12 (n = 1820), respectively. The incidence of newborn depression (1- or 5-minute Apgar score less than 7) was 14.1%; of these depressed newborns, the incidence of normal umbilical cord arterial pH values (greater than or equal to -2 SD) was 77.8%. Of the vigorous newborns, there was a 2.1% incidence of umbilical cord arterial blood acidemia. Umbilical cord arterial blood acidemia in vigorous newborns was not highly predictive of specific morbidity in the immediate newborn period. Regression analysis demonstrated the umbilical cord arterial pH to correlate best with the Apgar scores when compared with all other arterial or venous blood gas measurements. We reached the following conclusions: (1) that obtaining cord arterial pH values in vigorous newborns should be considered since the values will provide objective documentation or normal fetal acid base balance in 98% of infants. (2) Only a cord arterial pH determination is recommended since it reflects fetal or newborn status more accurately than all other measurements. Additional measurements increase the likelihood of abnormal results and do not contribute to neonatal management. (3) An umbilical cord blood pH value is extremely useful in ruling out the diagnosis of birth asphyxia in the depressed newborn.     

Total body water in small- and appropriate- for gestational age newborns

OBJECTIVES: To ascertain total body water in small for gestational age (SGA) and appropriate for gestational age (AGA) newborns. METHODS: SGA and AGA babies were matched by gestational age and studied from birth to term age. Criteria for exclusions were genetic syndromes, malformations, and congenital infections. Bioelectrical impedance was performed at two days of life (term infants), or at seven days of life and term age (preterm infants). Weight and length were measured by trained interviewers, and Z-score, weight/length ratio and Rohrer ponderal index was calculated. RESULTS: Of the 54 infants evaluated, 28 were SGA (17 preterm) and 26 were AGA (15 preterm). Total body water was greater in SGA preterm babies at seven days of age (P=0.058) and at term age (P<0.0001). Weight/length ratio and Rohrer ponderal index increased towards term. Weight Z-score and anthropometric measures at term were significantly smaller in SGA babies. Being SGA and variation in Rohrer ponderal index influenced the variations in total body water. CONCLUSIONS: SGA babies had greater total body water, and both groups presented insufficient increase in body solid mass, stressing the importance of nutritional support during neonatal care.     

Plasma adrenomedullin levels in pregnancies with appropriate for gestational age and small for gestational age infants.

AIMS: To evaluate whether maternal and fetal plasma adrenomedullin levels in pregnancies with small for gestational age (SGA) infants are different from those in pregnancies with appropriate for gestational age (AGA) infants. METHODS: Maternal and fetal circulating adrenomedullin levels were compared between 62 pregnancies with AGA (43 delivered vaginally and 19 delivered by elective cesarean section) and 28 pregnancies with SGA (20 delivered vaginally and 8 delivered by elective cesarean section) at birth. Plasma adrenomedullin levels were measured from maternal and cord venous blood samples using a radioimmunoassay. Umbilical artery blood pH was also measured. RESULTS: There were no significant differences for maternal total adrenomedullin levels, mature adrenomedullin levels, and its ratio among the groups. There were also no significant differences for fetal total adrenomedullin levels, mature adrenomedullin levels, and its ratio among the groups. In the AGA group delivered vaginally, fetal mature/total adrenomedullin ratio (mean +/- standard error, 16.6 +/- 0.7%) was significantly higher than the maternal ratio (13.8 +/- 0.6%) (p < 0.05). In the SGA group delivered vaginally, fetal mature/total adrenomedullin ratio (18.5 +/- 1.0%) was also significantly higher than the maternal ratio (14.5 +/- 0.6%) (p < 0.05). There was no significant difference in umbilical artery blood pH among the groups. CONCLUSIONS: These results suggest that maternal and fetal plasma circulating adrenomedullin levels may play a role in maternal and fetal cardiovascular adaptation during delivery in pregnancies with both AGA and SGA infants.     

Significance of high and normal neonatal nucleated red blood cell count in small-for-gestational-age newborns

The objective of this study was to evaluate the obstetrical and neonatal outcome in small-for-gestational age (SGA) and appropriate-for-gestational-age (AGA) fetuses with normal and elevated neonatal nucleated red blood cell counts. Therefore the nucleated red blood cell count was assessed immediately after birth in 906 neonates delivered at our institution and the perinatal and neonatal data were compared. Postnatally, infants were classified as SGA if they had a birth weight for given gestational age below the 10th percentile. Neonates were allocated to four groups according to their nucleated red blood cell count: SGA neonates with normal and high nucleated red blood cell count and appropriate-for-gestational-age newborns (AGA) with normal and high nucleated red blood cell count. Statistical analysis included the Mann-Whitney U-Test, Student's t-test, chi2 analysis of variance and stepwise regression analysis. SGA newborns with high nucleated red blood cell count had a significantly lower birth weight, a lower gestational age at delivery, lower arterial and venous pH values, lower Apgar scores at 1 min, 5 min and 10 min as well as lower base excess values compared to the other groups. They had to be transferred significantly more often and stayed longer in the neonatal intensive care unit. Three cases of intraventricular hemorrhage, four cases of necrotizing enterocolotis and two neonatal deaths occurred all in the SGA group with high neonatal nucleated red blood cell counts. Neonatal outcomes of SGA and AGA newborns with normal nucleated red blood cell counts were comparable. Our data do therefore underline the possible value of neonatal nucleated red blood cell counts to differentiate the healthy small-for-gestational age newborn from the truely growth retarded newborn.     

Blood coagulation and fibrinolysis in cord blood with reference to birth weight

To clarify the hemocoagulative and fibrinolytic dynamics of the perinatal period and also to seek the cause of SGA (small for gestational age) baby birth, the coagulation and fibrinolysis of the cord blood were examined, and moreover a comparison with the maternal blood, discussion on the difference in birth weight, and an examination of the difference due to the sex of babies were made in 68 cases with full-term, vaginal, spontaneous delivery, and the following conclusions were reached. In comparison with maternal blood, cord blood significantly showed any of the following: Prolongations of the prothrombin time, and the activated partial thromboplastin time, a decrease in fibrinogen, and a decrease in the platelet aggregation, antithrombin III, and plasminogen. In addition, high values for thromboxane B2 and 6-ketoprostaglandin F1 alpha were observed. In the SGA group, significant decreases were observed in the platelet count, antithrombin III, plasminogen, and alpha 2-plasmin inhibitor as compared with the AGA (appropriate for gestational age) and LGA (large for gestational age) baby groups. No sex difference was observed in the hemocoagulative and fibrinolytic capacities of the cord blood. These hemocoagulative and fibrinolytic capacities, particularly changes in the fibrinolytic system observed in the SGA group, seem to be attributable to chronic DIC (disseminated intravascular coagulation) and mild acidosis due to various stresses during pregnancy and at parturition, in turn due to immaturity of the liver in babies.     

The relationship among intrauterine growth, insulinlike growth factor I (IGF-I), IGF-binding protein-3, and bone mineral status in newborn infants

Insulinlike growth factors (IGFs) exert profound effects on somatic growth and cellular proliferation of many tissues and play an essential role in bone metabolism. The aim of this study was to investigate how fetal growth and bone mineralization correlate with IGF-I and IGF-binding protein-3 (IGFBP-3) levels of newborn infants and their mothers. In addition, we aimed to determine the predictive value of anthropometric measurements on variability in bone mineral status. Umbilical cord venous blood samples were obtained at delivery from 100 term newborn infants. Forty of the newborn infants had birthweights appropriate for gestational age (AGA), 30 were small for gestational age (SGA), and 30 were large for gestational age (LGA). Data were acquired using whole-body dual-energy X-ray absorptiometry scanner with a pediatric platform. Umbilical cord serum IGF-I concentrations were higher in LGA newborns ( P < 0.01), but lower in SGA newborns ( P < 0.01) than in AGA newborns. Umbilical cord serum IGFBP-3 concentrations in LGA newborns were significantly greater than in SGA and AGA newborns ( P < 0.01 and P < 0.01, respectively). Whole-body bone mineral density (WB BMD) was higher in LGA babies (0.442 +/- 0.025 g/cm2 [SD]; P < 0.01) but lower in SGA (0.381 +/- 0.027 g/cm 2; P < 0.0001) than in AGA babies (0.426 +/- 0.022 g/cm2). WB BMD and content (WB BMC) were correlated significantly with birthweight, birth height, head circumference, body mass index (BMI) of the infants; ponderal index and triceps skinfold thickness (reflecting fat stores) of the infants; cord serum IGF-I concentration, serum IGF-I concentration of the mothers; and fat mass, proportionate fat mass, weight, and BMI of the mothers. In contrast, WB BMC was also correlated positively with cord serum IGFBP-3 concentration and gestational age, and WB BMD was positively correlated with serum IGFBP-3 levels of the mothers. Umbilical cord serum IGF-I concentration of the infants was correlated significantly with the concentration of the mothers ( R = 0.232; P = 0.020). Umbilical cord serum IGF-I and IGFBP-3 concentrations were correlated significantly with the fat mass, gestational age, birthweight, birth height, head circumference, and BMI of the infants. Umbilical cord IGF-I concentration was also correlated with ponderal index and triceps skinfold thickness of the infants, maternal weight, BMI, and proportionate fat mass of the infants. Stepwise multiple regression analyses showed no significant relation between bone indices (WB BMD, WB BMC) and the infant's or mother's variations including serum IGF-I and IGFBP-3 concentrations. Birthweight and gestational age are related to bone indices. However, the present study does not provide support for the hypothesis that serum IGF-I and IGFBP-3 levels of infants and their mothers may play a major role in the regulation of bone metabolism in the developing skeleton.     

Maternal hemodynamics and impaired fetal growth in pregnancy-induced hypertension

Twenty-one subjects with pregnancy-induced hypertension were investigated with regard to the relationship between maternal hemodynamics and fetal growth. Five of the infants were small for gestational age (SGA) (less than tenth percentile) and 16 were appropriate for gestational age (AGA) (greater than tenth percentile). Mean arterial blood pressure, cardiac output, and stroke volume were significantly lower in the group of mothers with SGA infants than in the group with AGA infants (102 +/- 3 versus 115 +/- 3 mmHg, 5.8 +/- 0.2 versus 8.2 +/- 0.3 L/minute, and 76 +/- 7 versus 100 +/- 5 mL, respectively). The results of this investigation suggest that the hemodynamic background to the blood pressure increase in pregnancy-induced hypertension ranges from a low cardiac output, high vascular resistance condition to a high-output, low-normal resistance variant. The former subtype is often associated with the birth of an SGA infant.     

Severity of Hypertension in Pregnancy and Morbidity in the Newborn

A prospective study on the effect of severity of hypertension in pregnancy on peri- and neonatal morbidity was conducted over a 22 month period in 1984 - 1986 at Kuoplo University Central Hospital. Five hundred and fifty-four babies without major anomalies were born alive to hypertensive and 3212 to normotenslve mothers. The Incidence of prematurity was highest (22%) among babies with maternal pre-eclampsia, Intrauterine growth retardation (IUGR) being the most frequent (42%) among preterms from this group.

All preterm babies born at 28 - 36 gestational weeks were included for analysis of peri- and neonatal morbidity, 36 “in the pre-eclampsia group, 17 in the pregnancy-induced hypertension group, 11 in the chronic hypertension group and 162” in the normotenslve control group. The respective numbers of babies “in the full-term sample were 49, 74 and 51″ in the hypertension subgroups and 220” in the normotenslve control group.

Among preterm babies maternal pre-eclampsia was associated with the highest neonatal morbidity and birth asphyxia, expressed as reduced optimality scores, and with the lowest birth weight and length. Among full-term babies those with chronic maternal hypertension had the highest neonatal morbidity and birth asphyxia even though babies with maternal pre-eclampsia had the lowest birth weight. When appropriate for gestational age (AGA) and small for gestational age (SGA) children were examined separately, the differences described between the hypertension subgroups and their controls were found mostly between AGA children. Maternal hypertension explained 22% of the between-group differences” in preterm children, mostly via Increased IUGR, and 12%” in full-term children, mostly via increased neonatal morbidity.     

瘦素在胎盘组织中的表达及其与新生儿体重的关系

目的探讨瘦素在胎盘组织中的表达及其与新生儿体重的关系.方法采用放射免疫法(RIA)检测100例足月孕妇静脉血及其新生儿脐血瘦素水平,根据新生儿出生体重分为大于胎龄儿(LGA)组19例,适于胎龄儿(AGA)组65例,小于胎龄儿(SGA)组16例,同时采用逆转录-聚合酶链反应(RT-PCR)技术,检测41例胎盘组织中瘦素mRNA表达水平.结果(1)胎盘组织中瘦素mRNA表达水平为0.97±0.04,与新生儿体重呈显著正相关关系(r=0.43,P＜0.01).其中LGA组(1.01±0.03)显著高于AGA组(0.97±0.02),SGA组(0.93±0.03)显著低于AGA组,差异均有极显著性(P＜0.01).(2)母血瘦素水平为(14.22±7.66)μg/L,与新生儿体重无相关关系(r=0.11,P＞0.05).(3)新生儿脐血瘦素水平为(7.58±5.15)μg/L,与新生儿体重呈显著正相关关系(r=0.57,P＜0.01),其中LGA组脐血瘦素水平为(13.38±6.75)μg/L,显著高于AGA组的(7.40±4.45)μg/L,SGA组为(2.79±1.54)μg/L,显著低于AGA组,差异有极显著性(P＜0.01).结论脐血及胎盘组织中瘦素水平与胎儿生长发育状态密切相关;母血瘦素水平与新生儿体重无关;孕期胎儿瘦素的重要来源是胎盘组织.     

Neonatal nucleated red blood cell counts in small-for-gestational-age fetuses: relationship to fetoplacental Doppler studies

OBJECTIVE: To study the influence of pathologic umbilical and middle cerebral artery and uterine artery Doppler studies on the nucleated red blood cell count in small-for-gestational-age (SGA) fetuses. MATERIALS AND METHODS: Cord blood was prospectively collected during a 18-month period. 80 SGA fetuses (fetal abdominal circumference < 5th percentile) with Doppler ultrasound of the umbilical, the middle cerebral artery and both uterine arteries were enrolled in the study. SGA fetuses with normal Doppler flow velocity waveforms were allocated to group 1 (n = 23). Group 2 (n = 13) were fetuses with abnormal umbilical Doppler studies and group 3 (n = 44) were fetuses with both, pathologic umbilical and uterine artery Doppler studies. 2 fetuses in group 3 showed evidence of brain sparing, 3 fetuses presented absent-end-diastolic flow in the umbilical artery. Outcome measures included nucleated red blood cell count, Apgar scores, arterial pH and arterial base excess, venous pH, birth weight, gestational age at delivery, mode of delivery, rate of neonatal intensive care unit admission and length of stay in the neonatal intensive care unit. RESULTS: Highest nucleated red blood cell counts with lowest birth weight and gestational age were found in group 3. Decelerations of the fetal heart rate were more frequent in study group 3 and caesarean section for fetal indication was performed more often in this group. Those fetuses had to be transfered more often to the neonatal intensive care unit than fetuses of the other study groups. There was a tendency in group 3 towards lower arterial pH values and arterial base excess values. Fetuses with absent-end-diastolic flow in the umbilical artery presented highest nucleated red blood cell counts. CONCLUSION: In SGA fetuses increasing Doppler pathology seems to be correlated with increasing nucleated red blood cell count post-partum. Pathologic uterine artery flow results might have an additional impact on the number of nucleated red blood cells at birth.     

Apgar score, meconium and acidaemia at birth in small-for-gestational age infants born at term, and their relation to neonatal neurological morbidity

Summary. Neonatal neurological morbidity was studied in relation to Apgar score, meconium stained amniotic fluid and acidaemia at birth in 247 small-for-gestational age (SGA) maturely born infants. SGA infants, and especially the severely SGA infants and those born abdominally, showed higher rates of neurological morbidity, acidaemia and meconium stained amniotic fluid than appropriate-for-gestational age (AGA) controls. The examined indicators of asphyxia at birth showed slightly higher correlation coefficients with the 'neonatal neurological optimality score'(NNOS) in SGA, than in AGA term infants, but the percentage of explained variance was low, except in the 23 infants born abdominally. In this group poor neurological outcome was restricted to the 14 infants who showed signs of fetal hypoxaemia diagnosed by decelerative fetal heart rate (FHR) patterns. In 11 of them, FHR decelerations occurred antepartum. These FHR abnormalities appear to be better predictors for the neonatal neurological outcome than indicators of asphyxia at birth.     

A practical approach to umbilical artery pH and blood gas determinations.

The use of the Apgar score as a means of identifying birth asphyxia has been challenged. Routine umbilical cord blood pH has been recommended as a more objective measure of the condition of the newborn. The purposes of this study were to evaluate a simplified and selective method of umbilical artery pH blood sampling and to determine the effect of delay in sampling upon umbilical artery pH, carbon dioxide pressure (PCO2), and oxygen pressure (PO2). Umbilical arterial blood of 25 patients was sampled from clamped umbilical cord segments every 15 minutes for 1 hour after delivery. The clamped umbilical cord segments were left at room temperature with no special care given. The blood samples were collected in non-heparinized and non-iced plastic syringes and processed promptly after sampling. During the 60 minutes after delivery, there were no statistically significant changes in pH, PCO2, or PO2 of umbilical arterial blood. Our results indicate that umbilical arterial blood may be obtained simply and reliably from clamped umbilical cord segments for pH and gas determinations for up to an hour after delivery.     

The Apgar score, acid-base equilibrium of the umbilical cord vessels and early postnatal adaptation in healthy term newborns

The aim of the study is to establish a correlation between Apgar score, acid-base status (ABS) and blood gases (bg) from cord blood and the early postnatal adaptation in healthy term newborns. The study is prospective and includes 52 babies at term born at the State University Hospital Ma?chin Dom, Sofia during a three month period--03-05, 1998 without evidence of asphyxia before and during delivery. All babies are monitored for Apgar score at minute 1 and 5, ABS and bg from umbilical artery (u.a.) and vein (u.v.) examined at birth, as well as capillary ABS and bg 1 hour after birth. Early postnatal adaptation is judged by a neonatologist in the course of two hours. RESULTS: A significant difference is found between all the examined points in the ABS and the blood gases in samples from umbilical artery and vein (p < 0.05), most significantly differ pH, pO2 and O2 Sat (p < 0.001). There is a correlation between 1 minute Apgar score and ABS and bg from umbilical vessels, babies with 1 minute Apgar score 7 having significantly lower pH from u.a. requiring wider range of resuscitation. Babies with 1 minute Apgar score 9/8 and 5 minute Apgar score 10 have definitely less early adaptational problems. CONCLUSION: The use of a combination of evaluation criteria for the condition of the newborn after birth (Apgar score, ABS and bg from cord blood and strict monitoring of early cardio-pulmonary adaptation) guarantees adequate resuscitation in term babies.     

Apgar score, meconium and acidaemia at birth in small-for-gestational age infants born at term, and their relation to neonatal neurological morbidity

Neonatal neurological morbidity was studied in relation to Apgar score, meconium stained amniotic fluid and acidaemia at birth in 247 small-for-gestational age (SGA) maturely born infants. SGA infants, and especially the severely SGA infants and those born abdominally, showed higher rates of neurological morbidity, acidaemia and meconium stained amniotic fluid than appropriate-for-gestational age (AGA) controls. The examined indicators of asphyxia at birth showed slightly higher correlation coefficients with the 'neonatal neurological optimality score' (NNOS) in SGA, than in AGA term infants, but the percentage of explained variance was low, except in the 23 infants born abdominally. In this group poor neurological outcome was restricted to the 14 infants who showed signs of fetal hypoxaemia diagnosed by decelerative fetal heart rate (FHR) patterns. In 11 of them, FHR decelerations occurred antepartum. These FHR abnormalities appear to be better predictors for the neonatal neurological outcome than indicators of asphyxia at birth.     

Adverse perinatal outcome and maternal risk factors in population versus customized defined SGA babies

Objective.?The purpose of this study was to compare population and customized-based birth weight centiles in their association with perinatal outcome and maternal risk factors, in nulliparous Caucasian women in a socio-economic disadvantaged region.

Methods.?We analyzed perinatal outcomes in births of 302 Caucasian women of which 155 were small for gestational age (SGA) and 147 were appropriate for gestational age (AGA). Out of the overall study group, two cohort studies were designed. One was classified by population centiles as either SGA (n= 133) or AGA (n?= 169) and the other was classified by customized centiles as either SGA (n?= 131) or AGA (n?= 172). Maternal risk factors and operative delivery rates for fetal distress, Apgar scores, need for resuscitation and neonatal nursery care given, were determined for both customized and population-based SGA babies.

Results.?The customized SGA only group showed more mental health problems and special nursery in comparison with the AGA group. The population SGA only group had more smoking and mental health problems than the AGA group, but no differences on neonatal outcome measures.

Conclusion.?Use of customized centiles does identify an additional group neonates with a significantly higher need for special nursery admission in a homogeneous ethnic Caucasian group.     

胎盘肥胖基因表达与胎儿宫内生长发育相关性研究

目的　探讨胎盘肥胖基因表达与脐血瘦素水平和胎儿宫内生长发育的关系。　方法　采用逆转录定量聚合酶链反应 (RT- PCR)检测 40例胎盘肥胖基因 m RNA相对表达水平 ,采用放射免疫法检测脐血肥胖基因蛋白 (瘦素 )水平 ,采用 Ponderal指数 [PI=10 0×体重 (g) /身长 (cm) 3 ]估测新生儿营养状态。　结果　胎盘组织肥胖基因呈现高效表达 ,表达水平与孕母脂肪组织肥胖基因表达水平相似 ;13例小于胎龄儿胎盘组织瘦素 - m RNA相对表达水平为 0 .44 9± 0 .0 2 6 ,显著低于 15例适于胎龄儿的表达水平 [0 .487± 0 .0 42 (P<0 .0 5 ) ];12例大于胎龄儿胎盘组织瘦素 - m RNA相对表达水平为 0 .5 2 5± 0 .0 2 9,显著高于适于胎龄儿 (P<0 .0 5 )。胎盘肥胖基因 m RNA相对表达水平与脐血瘦素水平显著相关 (r=0 .6 1,P<0 .0 5 ) ,与新生儿出生体重和 Ponderal指数显著相关 (r=0 .6 0和0 .5 6 ,P<0 .0 5 )。　结论　胎盘是脐血瘦素重要来源 ,胎盘瘦素可能对胎儿宫内生长发育有促进作用     

Reference curves of symphysis-fundus height in twin pregnancies

OBJECTIVE: To generate reliable new reference ranges for symphysis-fundus height (SFH) in twin pregnancies using modern statistical methods and to evaluate whether small-for-gestational age (SGA) babies of women who had a SFH measurement after the 25th gestational week could be predicted by the SFH measurement in the reference curves and other maternal data. STUDY DESIGN: In a retrospective cross-sectional study at the obstetric outpatient clinic, Zurich University Hospital, SFH was determined in 257 twin-pregnant women with accurately dateable twin pregnancies (Caucasians: N=217, Asians: N=15, Blacks: N=10, and 15 others). Exclusion criteria were intrauterine fetal death, and known fetal and maternal diseases, which influence SFH. Pregnant women with twins were divided in three groups according to the birth weight of the babies. Group I: both babies were appropriate for gestational age (AGA), group II: one baby was AGA and one SGA, and group III: both babies were SGA. RESULTS: SFH measurements increased linearly with gestational age (GA). The following rule of thumb is suggested for the 50th centile of SFH (cm)=gestational week+10% of gestational week. Age, height, weight and body mass index (BMI) before pregnancy, parity and ethnic group were insignificant determinants in SFH measurement. A prognostic score for identification of group III was created for a GA> or =25 weeks and BMI<30 kg/m2. CONCLUSIONS: Measuring SFH is simple, inexpensive and non-invasive and may be of some use for identifying twin mothers with SGA twin pairs.     

Iron status at birth and at 4 weeks in term small-for-gestation infants in comparison with appropriate-for-gestation infants

Objective.?To determine body iron stores at birth in term small-for-gestational age (SGA) infants as compared to appropriate-for-gestational age (AGA) infants.

Methods.?In this prospective study, mother–infant pairs with gestation of?≥37 weeks and birth weight of at least 1.5?kg were enrolled. Asymmetric SGA infants were taken as cases and term AGA infants as controls. Maternal, cord blood, and infant blood samples at 4 weeks were obtained for measurement of various iron indices – cord serum ferritin, serum ferritin at 4 weeks, and correlation among maternal and neonatal iron indices – Hb, serum iron, ferritin, and total iron binding capacity (TIBC).

Results.?There were 50 SGA and 50 AGA mother–infant pairs. Cord serum ferritin levels were low in SGA group as compared to AGA [median (IQR): 68 (30,136) vs. 141 (63,259), p?=?0.007]. The proportion of infants with ‘low’ cord ferritin (<40?μg/l) were more in SGA [p?=?0.05]. There was no correlation among various maternal and neonatal cord iron parameters. The serum ferritin levels at 4 weeks were similar in both the groups (p?=?0.16).

Conclusions.?Term SGA infants have lesser total iron stores as compared to AGA infants at birth. Future studies can be designed to look at long-term neurodevelopmental outcome of the SGA babies with low as well as normal ferritin and also the role of early iron supplementation in term SGA neonates.