Increased immunoreactive erythropoietin in cord serum after labor

Since several hours of hypoxemia in fetal animals is sufficient to cause an increase in the plasma erythropoietin level and since labor may be associated with fetal hypoxemia, this study was undertaken to determine if erythropoietin levels in cord blood were higher in fetuses subjected to labor. Two groups of term (37 to 41 weeks) singleton pregnancies were compared: (1) those delivered by elective repeat cesarean section without prior labor (n = 18) and (2) those delivered vaginally (n = 23). Erythropoietin was measured by a radioimmunoassay in which a highly purified human erythropoietin (70,000 U/mg of protein) was used and which has a sensitivity limit of 4 to 5 mU/ml. The mean cord serum erythropoietin level was higher in pregnancies with labor (46 +/- 34 mU/ml, mean +/- SD) compared to those without (26 +/- 10, p less than 0.02). There were no differences between the two groups for maternal age, gestational age, birth weight, infant sex, or Apgar scores. No association of erythropoietin with either gestational age or sex was found. In 11 pregnancies without labor, comparisons were made among simultaneously obtained samples of umbilical arterial plasma, umbilical venous plasma, and mixed cord serum. Although there were no differences between umbilical arterial and umbilical venous plasma erythropoietin levels (21.3 +/- 9.3 versus 19.0 +/- 7.8 mU/ml), mixed cord serum was inexplicably higher (24.4 +/- 9.5 mU/ml, p less than 0.01). We concluded that in uncomplicated pregnancies the duration and intensity of labor are sufficient to cause an increase in the fetal erythropoietin level at delivery.     

脐血胆红素对ABO溶血病足月儿高胆红素血症的预测价值

目的 研究脐血胆红素水平预测ABO溶血病足月儿发生高胆红素血症的价值.方法 回顾性分析同济大学附属第一妇婴保健院新生儿科2011年8月1日至2012年7月31日收治的292例足月ABO溶血病患儿的脐血胆红素水平.比较发生高胆红素血症(高胆组,34例)和未发生高胆红素血症(非高胆组,258例)患儿的临床特征.采用配对f检验、x2检验和Spearman相关分析对数据进行分析.构建受试者工作特性(receiver operating characteristic,ROC)曲线,分析脐血胆红素水平预测高胆红素血症的准确度及界值(cut-off point). 结果 高胆组34例患儿平均脐血胆红素水平为(52.4±13.2) μmol/L,明显高于非高胆组的(35.0±8.0) μmol/L(t=7.540,P=0.001).脐血胆红素水平与高胆红素血症发生率明显相关(x2=113.715,P＜0.001; rs=7.19,P＜0.001).新生儿脐血胆红素水平为50μmol/L时,发生黄疸的阳性预测值为0.683,阴性预测值为0.959,敏感性为0.690,特异性为0.958,ROC曲线下面积为0.882 (95％CI:0.873～0.891,P＜0.001).结论 脐血胆红素水平可作为预测ABO溶血病足月儿发生黄疸及预测黄疸程度的有效指标.     

Plasma immunoreactive erythropoietin in normal women studied sequentially during and after pregnancy

Six healthy, nonanemic women with uncomplicated singleton pregnancies were sequentially studied for plasma immunoreactive erythropoietin levels, hematologic indices, and human placental lactogen. Mean group levels of erythropoietin as well as human placental lactogen were significantly increased (p less than 0.01) after 18 weeks' gestation compared to nonpregnant values (20 to 30 weeks post partum). However, individual responses of erythropoietin during pregnancy were found to be highly variable. There was a direct correlation of both maternal plasma erythropoietin and human placental lactogen with gestational age (p less than 0.001) but no detectable relation of erythropoietin with human placental lactogen levels. We speculate that the increase in erythropoietin levels during pregnancy acts as a trophic stimulus for effecting an increase in maternal red blood cell mass presumably to meet the increased metabolic (oxygen) demands of pregnancy.     

Umbilical cord plasma interleukin-6 concentrations in preterm infants and risk of neonatal morbidity

OBJECTIVE: This study was undertaken to evaluate the association between umbilical cord interleukin-6 (IL-6) levels and neonatal morbidity in infants born at less than 32 weeks' gestation. STUDY DESIGN: Umbilical cord plasma IL-6 levels and neonatal outcomes were assessed in 309 infants born between 24 weeks and 0 days' and 31 weeks and 6 days' gestation. RESULTS: Mean IL-6 levels were higher in spontaneous (n = 193, 355 +/- 1822 pg/mL) compared with indicated preterm births (n = 116, 37 +/- 223 pg/mL, P < .0001). Adjusting for gestational age, a progressive relationship was noted between increasing IL-6 levels and increased risk of neonatal systemic inflammatory response syndrome (SIRS). IL-6 levels beyond the 90th percentile (> or =516.6 pg/mL) were also significantly associated with periventricular leukomalacia (PVL; odds ratio [OR] 15, 95% CI 2-149) and necrotizing enterocolitis (NEC; OR 6, 95% CI 1.1-33). In the multivariate analysis, an IL-6 level 107.7 pg/mL or greater (determined by receiver operating curve analysis) remained a significant independent risk factor for PVL (OR 30.3, 95% CI 4.5-203.6). CONCLUSION: Umbilical cord IL-6 levels are higher in preterm infants born after spontaneous preterm labor or premature rupture of membranes. Elevated IL-6 levels are associated with an increased risk for SIRS, PVL, and NEC in infants born at less than 32 weeks' gestation.     

Changes in serum immunoreactive erythropoietin during the menstrual cycle and normal pregnancy

Immunoreactive erythropoietin was estimated in samples of serum collected during the follicular and luteal phases of the menstrual cycle in seven women and in sera collected sequentially throughout normal pregnancy in these and three other women. Estimates of serum erythropoietin during the follicular and luteal phases of the menstrual cycle were almost identical. During pregnancy in all 10 subjects serum erythropoietin increased at some time after 8 weeks gestation. These changes were not related to other endocrine values, to indicators of haematological and renal function or to infant birthweight except that changes in serum erythropoietin and placental lactogen were related (P less than 0.00001). In one other woman treated over 17 weeks of pregnancy with continuous intravenous infusion of salbutamol, erythropoietin levels were within the range found in normal pregnancies.     

Changes in serum immunoreactive erythropoietin during the menstrual cycle and normal pregnancy

Summary. Immunoreactive erythropoietin was estimated in samples of serum collected during the follicular and luteal phases of the menstrual cycle in seven women and in sera collected sequentially throughout normal pregnancy in these and three other women. Estimates of serum erythropoietin during the follicular and luteal phases of the menstrual cycle were almost identical. During pregnancy in all 10 subjects serum erythropoietin increased at some time after 8 weeks gestation. These changes were not related to other endocrine values, to indicators of haematological and renal function or to infant birthweight except that changes in serum erythropoietin and placental lactogen were related ( P < 0.00001). In one other woman treated over 17 weeks of pregnancy with continuous intravenous infusion of salbutamol, erythropoietin levels were within the range found in normal pregnancies.     

Obstetric analgesia and immunoreactive endorphin peptides in maternal plasma during labor

We studied the effect of obstetric analgesia on maternal plasma levels of immunoreactive endorphin peptides (ir-EP) during labor and the postpartum period in three groups of parturients: group I (n = 22) had no analgesia, group II (n = 20) received pethidine intramuscularly, and group III (n = 10) had continuous epidural analgesia. Initial levels of ir-EP were similar in all three groups. Patients without any medication and patients on pethidine showed a significant rise in ir-EP in late labor and at delivery. Epidural analgesia was characterized by constant levels of ir-EP during labor and an insignificant rise at delivery.     

Amniotic fluid erythropoietin correlates with umbilical plasma erythropoietin in normal and abnormal pregnancy

In the human fetus, elevated plasma erythropoietin levels have been found in high-risk pregnancies at delivery. We examined the relationship of amniotic fluid erythropoietin and umbilical plasma erythropoietin at delivery in 17 normal pregnancies, 41 hypertensive pregnancies, and 37 insulin-treated diabetic pregnancies terminated by elective cesarean section without labor. An additional 27 insulin-treated diabetic patients were studied after undergoing variable durations (86-1184 minutes) of labor. Erythropoietin was analyzed using a highly sensitive and specific radioimmunoassay technique. Fetal plasma erythropoietin concentrations were elevated above the control upper range (50.3 mU/mL) in 59% of the hypertensives and in 38% of the diabetics. The amniotic fluid erythropoietin values were significantly lower than the umbilical plasma erythropoietin values in each study group. Although the umbilical plasma erythropoietin values in the abnormal pregnancy groups differed considerably from the corresponding levels in the controls, the ratio of amniotic fluid erythropoietin to umbilical plasma erythropoietin was approximately the same in controls, hypertensives, and diabetics. Furthermore, the plasma and amniotic fluid levels (In transformed) correlated highly significantly in all three individual groups in absence of labor. In the diabetic labor group, this relationship was nonsignificant. We conclude that in the absence of labor, amniotic fluid erythropoietin reflects fetal plasma erythropoietin. We speculate that amniotic fluid erythropoietin may be an antepartum indicator of fetal hypoxemia.     

Increased myometrial responsiveness to oxytocin during term and preterm labor

The contractile effects of oxytocin on the longitudinal and circular muscle of rat uteri from animals undergoing term and preterm labor were studied in vitro to define the action of the hormone. The maximal tension and slopes of oxytocin dose contractile-response curves, but not the pD2 values (-log ED50), were higher in both muscle layers at term delivery and also during preterm delivery induced with antiprogesterones compared with responses from tissues of nondelivering animals. These data indicate that the myometrium is hyperresponsive and hyperreactive to oxytocin during term and preterm birth but not hypersensitive. The increase in oxytocin responsiveness of the myometrium may be fundamental to the initiation of labor and regulated by the increases in oxytocin receptors and postreceptor events, including gap junctions.     

Antecedents and outcome of very early neonatal seizures in infants born at or after term

Recent experimentally derived evidence has confirmed earlier suggestions that seizures which occur within 48 h of birth in babies born at or later than 37 completed weeks gestation are particularly likely to reflect intrapartum asphyxia. We have compared 54 cases of such seizures with 41,090 controls in a geographically defined population. Nulliparity, hydramnios, post-term pregnancy, oxytocin augmentation of labour, abnormalities of fetal heart rate and/or meconium-stained amniotic fluid, prolonged second stage of labour, emergency caesarean section, assisted vaginal delivery, low Apgar score and resuscitation at delivery and subsequent ventilatory support were all statistically significantly more common among cases than among controls. Five of the 54 babies who developed seizures died within 28 days of birth and 11 of the 49 survivors had an impairment diagnosed by 3 years of age which was usually associated with some degree of cerebral palsy. Comparison of the frequency of antecedent perinatal risk factors in the seizure babies who died, those who survived with disabilities and normal survivors failed to reveal any clear pattern.     

Decreased neonatal tibial bone ultrasound velocity in term infants born after breech presentation.

OBJECTIVE: Fetuses found to be in the breech presentation have limited motion of their lower limbs. The aim of this study was to test the hypothesis that bone speed of sound (SOS) would be lower in infants born after breech presentation than in those born after vertex presentation. STUDY DESIGN: We studied 127 singleton, appropriate for gestational age, term infants delivered by a scheduled cesarean delivery at approximately 38 weeks of gestation because of breech presentation or repeat elective cesarean section with vertex presentation. We used the Sunlight Omnisense 7000p device to measure axially transmitted SOS of the right tibia within the first 96 h of life. RESULT: Fifty-three infants studied (42%) were born by cesarean section after breech presentation compared to 74 vertex controls. Bone SOS was significantly lower in the breech presentation group, even after taking into account the effect of gender and parity (as well as gestational age at birth and birth weight). CONCLUSION: Bone SOS is lower in infants born after breech presentation than in those born after vertex presentation. We speculate that limited motion of lower limbs in fetuses found to be in the breech presentation leads to a decrease in bone mineralization and strength.     

Pulmonary excretion of carbon monoxide in the human infant as an index of bilirubin production. IIc. Evidence for the possible association of cord blood erythropoietin levels and postnatal bilirubin production in infants of mothers with abnormalities of gestational glucose metabolism

A total of 20 infants who had levels of erythropoietin (Ep), the major hormone regulating erythropoiesis, measured in their cord blood also had determinations of the pulmonary excretion rate of CO (VECO) performed, as an index of total bilirubin production. They were either infants of normal mothers or those of mothers with diabetes, gestational diabetes, and missed abnormalities of gestational glucose metabolism. The mean VECO (13.0 +/- 3.5 mu 1/kg/hr) and the mean Ep (20.0 +/- 9.7 SD mU/ml) of the infants with normal mothers (n = 9) were not different from the means previously established by our laboratories (13.9 +/- 3.5 SD mu 1/kg/hr, n = 20; and 23.7 +/- 12.8 SD mU/ml, n = 30, respectively); they were significantly lower than those of the infants of the abnormal mothers in this study. The 5 infants who had a cord blood Ep level greater than 50 mU/ml had a higher mean VECO, 27.8 +/- 7.1 mu 1/kg/hr, compared with 17.2 +/- 4.9 SD mu 1/kg/hr, of the six infants with cord blood Ep levels that were within 2 SD of the previously established normal mean cord blood Ep level (p less than .025). These data suggest that increased cord blood Ep levels and postnatal bilirubin production in infants whose mothers had abnormalities of gestational glucose metabolism are associated phenomena. Since polycythemia did not occur in these infants, ineffective erythropoiesis or mild, compensated hemolysis remains a likely cause of the increased total bilirubin production. In some cases, perinatal hypoxic stress may have affected the Ep response.(ABSTRACT TRUNCATED AT 250 WORDS)     

Phototherapy increases hemoglobin degradation and bilirubin production in preterm infants.

OBJECTIVE: To compare hemoglobin degradation and bilirubin production before and during phototherapy in preterm infants. BACKGROUND: Hemoglobin is catabolized into globin and heme, which is degraded by microsomal heme oxygenase into equimolar carbon monoxide and biliverdin. Biliverdin is then reduced into bilirubin. CO is excreted exclusively by the lungs; therefore, end-tidal carbon monoxide, corrected for inhaled CO (ETCOc), reflects hemoglobin degradation and total bilirubin production. METHOD: A prospective study design was used, including a study group of 24 preterm infants requiring phototherapy. Infants with hemolytic diseases, sepsis, recent blood transfusion, and infants on mechanical ventilation were excluded. ETCOc was measured in preterm infants before and during phototherapy. Hemoglobin degradation and bilirubin production were calculated by measuring ETCOc. RESULTS: The (mean +/- SD) birth weight of 24 preterm neonates was 1975 +/- 613 gm, gestational age was 32.7 +/- 2.3 weeks, hematocrit was 47.5 +/- 6.2 volume%, and peak bilirubin was 13.1 +/- 3.2 mg/dl. First ETCOc measurements were done at 59.6 +/- 22.2 hours of age immediately before starting phototherapy. The second ETCOc measurements were taken at 13.7 +/- 7.9 hours after starting phototherapy. The second measurement of 2.6 +/- 0.6 ppm (mean +/- SD) was significantly higher than the first ETCOc of 2.1 +/- 0.6 ppm (p < 0.05). CONCLUSION: Phototherapy increases hemoglobin degradation and bilirubin production in preterm infants.     

Maternal and neonatal outcomes after uterine rupture in labor

OBJECTIVE: There is significant controversy about the risks related to attempted vaginal birth after cesarean and the implications for informed consent of the patient. Recent data suggest that women who deliver in hospitals with high attempted vaginal birth after cesarean rates are more likely to experience successful vaginal birth after cesarean, as well as uterine ruptures. We conducted a study to evaluate maternal and neonatal morbidity and mortality after uterine rupture at a tertiary care center. STUDY DESIGN: We performed a retrospective chart review of cases of uterine rupture from 1976 to 1998. All women who had a history of uterine rupture were identified with International Classification of Diseases, Ninth Revision, identifiers with hospital discharge data cross-referenced with a separate obstetric database. We abstracted demographic information, fetal heart rate patterns, maternal pain and bleeding patterns, umbilical cord gas values, and Apgar scores from the medical record. Outcome variables were uterine rupture events and major and minor maternal and neonatal complications. RESULTS: During the study period there were 38,027 deliveries. The attempted vaginal birth after cesarean rate was 61.3%, of which 65.3% were successful. We identified 21 cases of uterine rupture or scar dehiscence. Seventeen women had prior cesarean deliveries (10 with primary low transverse cesarean delivery, 3 with unknown scars, 1 with classic cesarean delivery, 2 with two prior cesarean deliveries, and 1 with four prior cesarean deliveries). Of the 4 women who had no history of previous uterine surgery, one had a bicornuate uterus whereas the others had no factors increasing the risk for uterine rupture. We confirmed uterine rupture and scar dehiscence in 19 women. Specific details were not available for 2 patients. Uterine rupture or scar dehiscence was clinically suspected in 16 women with 3 cases identified at delivery or after delivery. Sixteen women had symptoms of increased abdominal pain, vaginal bleeding, or altered hemodynamic status. There were 2 patients who required hysterectomies and 3 women who received blood transfusions; there were no maternal deaths related to uterine rupture. The fetal heart rate pattern in 13 cases showed bradycardia and repetitive variable or late decelerations. Thirteen neonates had umbilical artery pH >7.0. Two cases of fetal or neonatal death occurred, one in a 23-week-old fetus whose mother had presented to an outlying hospital and the second in a 25-week-old fetus with Potter's syndrome. All live-born infants were without evidence of neurologic abnormalities at the time of discharge. CONCLUSION: Our data confirm the relatively small risk of uterine rupture during vaginal birth after cesarean that has been demonstrated in previous studies. In an institution that has in-house obstetric, anesthesia, and surgical staff in which close monitoring of fetal and maternal well-being is available, uterine rupture does not result in major maternal morbidity and mortality or in neonatal mortality.