Presence Of Labor Research Articles

Immunohistochemical localization of phospholipase A 2 isoforms in human myometrium during pregnancy and parturition

OBJECTIVE: The purpose of this study was to localize secretory phospholipase A 2 and cytosolic phospholipase A 2 isoforms in pregnant human myometrium and to determine changes in expression with gestational age or parturition. STUDY DESIGN: Myometrium was collected at cesarean section at term (>37 weeks) or preterm (<37 weeks) from patients who were or were not in labor ( n = 5 each group). Frozen sections were incubated with specific monoclonal antibodies against secretory phospholipase A 2 or cytosolic phospholipase A 2 and immunostaining visualized with the Vectastain ABC method. The intensity of immunostaining in different cellular localizations was scored by an investigator blinded to tissue identity and compared among tissues with use of the Mantel-Haenszel χ 2 test. RESULTS: Secretory phospholipase A 2 immunostaining was dispersed in the perinuclear region throughout the myometrial smooth muscle fibers and in vascular smooth muscle. Cytosolic phospholipase A 2 immunostaining was predominantly localized to endothelial cells of myometrial blood vessels and weakly throughout myometrial fibers. There was no apparent change in intensity of immunostaining for either isoform with gestational age or with the absence or presence of labor. CONCLUSION: The differential localization of the two phospholipase A 2 isoforms suggests different functions. The apparent lack of change in expression during late gestation or with labor possibly suggests changes in myometrial phospholipase A 2 activity and hence local myometrial arachidonic acid mobilization and presumably prostaglandin synthesis may not be associated with the onset of or maintenance of parturition. (Am J Obstet Gynecol 1997;176:878-82.)

Cord blood thyrotrophin and foetal presentation at delivery in singleton pregnancies.

Cord blood thyrotrophin (TSH) levels of 134 patients with singleton pregnancies and breech presentation at delivery were compared with those of cephalic-presenting controls matched for mode of delivery, the presence of labour, parity, and the date of delivery. Infants delivered by vaginal breech delivery were found to have a higher incidence of elevated cord blood TSH level than either cephalic-presenting infants or breech-presenting infants delivered by Caesarean section. We conclude that vaginal breech delivery can be associated with false positive congenital hypothyroidism screening.

Prenatal and Perinatal Risk and Protective Factors for Neonatal Intracranial Hemorrhage

Objective: To identify prenatal and perinatal risk and protective factors for grade III and IV intracranial hemorrhage (ICH) in 4795 singleton infants (weight, ≤1500 g). Method: Prenatal and perinatal risk and protective factors for ICH were examined initially by univariate analysis and adjusted for year of birth, followed by multivariate logistic regression analysis that adjusted simultaneously for the effects of year of birth and prenatal and perinatal characteristics. Setting: Seven tertiary care neonatal-perinatal centers. Results: By univariate analysis, African-American race, prenatal care, older maternal age, hypertension or preeclampsia, antenatal steroid administration, cesarean section delivery, increasing birth weight, increasing gestational age, and female gender of the infant were protective prenatal or perinatal factors. Antepartum hemorrhage, the presence of labor, and breech presentation were perinatal factors that were associated with an increased risk of ICH. By using staged logistic regression, a model of combined prenatal and perinatal characteristics that influenced grade III and IV ICH was developed. Significant protective factors against ICH included a complete course of antenatal steroid therapy, African-American maternal race, female gender of the infant, hypertension or preeclampsia with no antepartum hemorrhage, increasing gestational age, and increasing birth weight. Conclusion: Antenatal steroid administration is a therapeutic intervention that is associated with a decreased risk for neonatal grade III and IV ICH. (Arch Pediatr Adolesc Med. 1996;150:491-497)

Prenatal and perinatal risk and protective factors for neonatal intracranial hemorrhage. National Institute of Child Health and Human Development Neonatal Research Network.

To identify prenatal and perinatal risk and protective factors for grade III and IV intracranial hemorrhage (ICH) in 4795 singleton infants (weight, < or = 1500 g). Prenatal and perinatal risk and protective factors for ICH were examined initially by univariate analysis and adjusted for year of birth, followed by multivariate logistic regression analysis that adjusted simultaneously for the effects of year of birth and prenatal and perinatal characteristics. Seven tertiary care neonatal-perinatal centers. By univariate analysis, African-American race, prenatal care, older maternal age, hypertension or preeclampsia, antenatal steroid administration, cesarean section delivery, increasing birth weight, increasing gestational age, and female gender of the infant were protective prenatal or perinatal factors. Antepartum hemorrhage, the presence of labor, and breech presentation were perinatal factors that were associated with an increased risk of ICH. By using staged logistic regression, a model of combined prenatal and perinatal characteristics that influenced grade III and IV ICH was developed. Significant protective factors against ICH included a complete course of antenatal steroid therapy, African-American maternal race, female gender of the infant, hypertension or preeclampsia with no antepartum hemorrhage, increasing gestational age, and increasing birth weight. Antenatal steroid administration is a therapeutic intervention that is associated with a decreased risk for neonatal grade III and IV ICH.

The effect of manual removal of the placenta on post-cesarean endometritis

To determine if intraoperative glove change and placental delivery method affect the post-cesarean endometritis rate. After informed consent, women who required cesarean were randomly assigned to one of four study groups: 1) no glove change plus manual placental extraction, 2) no glove change plus spontaneous placental delivery, 3) glove change plus manual extraction, and 4) glove change plus spontaneous delivery. Bilateral glove change by both primary and assistant surgeons occurred immediately after delivery of the newborn and before delivery of the placenta. External uterine massage and traction on the umbilical cord were performed to assist spontaneous delivery of the placenta. A first-generation cephalosporin was routinely administered after umbilical cord clamping for prophylaxis of post-cesarean endometritis. Of 760 women entered into the study, we included 643 who did not have intrapartum chorioamnionitis or cesarean hysterectomy. The four groups were comparable with respect to selected maternal and intrapartum characteristics, including maternal and gestational age, parity, presence of labor, and the presence and duration of membrane rupture. The postoperative endometritis rate was significantly higher in women whose placentas were extracted manually (31 versus 22%, P = .01). Operator glove change did not alter the incidence of endometritis (relative risk 1.0, 95% confidence interval 0.79-1.3). Manual extraction of the placenta is associated with a significantly greater risk of post-cesarean endometritis than that observed with assisted spontaneous placental delivery. Intraoperative glove change does not decrease post-cesarean endometritis.

Umbilical plasma concentration of endothelin-1 in intrapartum fetal stress: effect of fetal heart rate abnormalities

To measure the umbilical plasma concentration of endothelin (ET)-1 in the presence of labor, fetal heart rate (FHR) abnormalities, and fetal hypoxia. Umbilical and maternal plasma concentrations of ET-1 were measured in 100 pregnant women at full-term deliveries (60 with vaginal delivery without induction and 40 with elective cesarean delivery without labor). We assessed the FHR pattern, measured umbilical blood gases and plasma concentration of vasopressin, and investigated the relationships between the umbilical vein-artery ET-1 concentration difference and these variables. The concentration of ET-1 in the umbilical vein was higher than in the umbilical artery and the maternal vein in all cases. The umbilical vein-artery ET-1 concentration difference (mean +/- standard error of the mean) was significantly greater in the vaginal delivery group (4.5 +/- 2.0 pmol/L) than in those delivered by elective cesarean (1.7 +/- 1.5 pmol/L) (P < .05). The umbilical vein-artery ET-1 concentration difference was significantly greater when more than three episodes of severe variable decelerations occurred during the 30-minute period before delivery (7.0 +/- 2.0 pmol/L) than in the absence of any decelerations (1.6 +/- 1.5 pmol/L) (P < .05). The umbilical vein-artery ET-1 concentration difference correlated positively with the umbilical arterial concentration of vasopressin (r = 0.45, P < .05) and negatively with the umbilical arterial oxygen pressure (r = -0.47, P < .05). In cases of vaginal delivery with FHR abnormalities and with fetal hypoxia, the fetoplacental concentration of ET-1 was increased.

Antenatal risk factors for germinal matrix hemorrhage and intraventricular hemorrhage in preterm infants

This study was designed to evaluate the effect of antenatal risk factors on the occurrence of germinal matrix hemorrhage or intraventricular hemorrhage in preterm infants. Antenatal factors were evaluated in 302 infants delivered between 24 and 33 completed weeks gestation. Ultrasonographic screening of intracranial hemorrhage was carried out in all the infants. The association between risk factors and neonatal intracranial hemorrhage was evaluated with both univariate and multivariate models. In stepwise logistic regression analysis, birthweight was a better predictor of neonatal germinal matrix hemorrhage than gestational age. Conversely, gestational age better predicted intraventricular hemorrhage than did birthweight. Risk factors for neonatal germinal matrix hemorrhage and intraventricular hemorrhage were dissimilar. A history of heavy (> 10 cigarettes/day) maternal smoking on admission increased the risk of germinal matrix hemorrhage three-fold (odds ratio = 3.35; 95% C.I. 1.24-9.07). Antenatal corticosteroid use reduced the risk of intraventricular hemorrhage by 76% (odds ratio = 0.24; 95% C.I. 0.09-0.61). Among patients with spontaneous preterm delivery or premature rupture of fetal membranes, the presence of labor was a significant effect modifier of the gestational-age associated risk of germinal matrix hemorrhage-intraventricular hemorrhage. Risk factors for neonatal germinal matrix hemorrhage are different from those for intraventricular hemorrhage. Most antenatal factors, especially those affecting fetal maturity, could influence the progression rather than the onset of intracranial hemorrhage.

Cranial Ultrasound Prediction of Disabling and Nondisabling Cerebral Palsy at Age Two in a Low Birth Weight Population

To employ multivariate analytic techniques to assess the association between neonatal cranial ultrasound (US) abnormalities and subsequent cerebral palsy (CP), defined as disabling CP (DCP) or nondisabling CP (NDCP) depending on the level of motor dysfunction. Prospective cohort study. The Neonatal Brain Hemorrhage Study enrolled a geographically representative sample of 1105 newborns 501 to 2000 g and obtained follow-up data on 777 (86%) of the 901 survivors at age two. One hundred thirteen children (14.6%) had motor findings severe enough to classify them as having CP. The 61 (7.9%) of these children who were disabled by their motor impairment we classified as having DCP. The remaining 52 (6.7%) who had definite neurologic findings (usually mild spastic diplegia) but without evidence of interference with daily living, we classified as having NDCP. In a multivariate logistic regression model of perinatal and postnatal variables, the following factors were found to be significant risk factors for DCP: parenchymal echodensities/lucencies or ventricular enlargement (PEL/VE) on cranial US (OR = 15.4; 7.6, 31.1), germinal matrix/intraventricular hemorrhage (GM/IVH) (OR = 3.5; 1.7, 6.9) and mechanical ventilation (OR = 2.9; 1.2, 7.1). Fully 93.4% of infants were correctly classified as to presence or absence of DCP on the basis of this model. Birth weight, gestational age, length of hospital stay, gender, race, plurality, presence of labor and Apgar score were not significant independent predictors of DCP. For NDCP, the only risk factor significant in the multivariate model was PEL/VE (OR = 5.3; 2.2, 12.6). Among perinatal and postnatal factors, cranial US abnormalities are by far the most powerful predictors of disabling CP in low birth weight infants. Although PEL/VE was the strongest predictor, GM/IVH also appeared to independently contribute to the risk of DCP. NDCP in low birth weight infants appears to have a different risk profile than DCP. In particular, it is less closely related to US evidence of perinatal brain injury.

The effect of labor on the normal values of umbilical blood acid-base status.

Although several investigators have attempted to define the normal values of umbilical cord blood pH and gases, there is considerable controversy about the optimal cutoff values to diagnosis intrauterine asphyxia. A possible reason for this might be that several studies have included data from fetuses born after different duration of labor. To determine the effect of labor and the duration of second stage on labor on umbilical arterial acid-base status at birth in healthy term infants. Umbilical artery acid-base status was determined in patients (n = 356) who met the following criteria: 1) singleton term pregnancy with no significant medical, obstetric, or neonatal complications; 2) vertex presentation if delivered vaginally; 3) neither regional nor general anesthesia applied if delivered vaginally; 4) no use of oxytocin; 5) normal fetal heart rate patterns; 6) clear amniotic fluid; 7) Apgar scores at 1 and 5 min > or = 7; 8) appropriate fetal weight for gestational age. Patients were divided into three groups. A-patients delivered by cesarean section (CS) in the absence of labor (n = 135); B-patients delivered by CS during first stage of labor (n = 62); C-patients with vaginal birth (n = 159). A Kruskal-Wallis ANOVA with post-hoc procedures and stepwise multiple regression analysis were performed. 1) There were significant differences in cord arterial acid-base values between study groups (pH: no labor CS, 7.27 +/- 0.05 vs labor CS, 7.26 +/- 0.05 vs vaginal birth, 7.24 +/- 0.07, p < 0.00001). 2) There was a significant fall in cord arterial pH and bicarbonate concentrations with increased duration of second stage of labor in newborns born vaginally (pH: duration of second stage, 1-30 min, 7.25 +/- 0.07 vs 31-60 min, 7.22 +/- 0.06 vs > 61 min, 7.21 +/- 0.07, p < 0.05). 3) Analysis of confounding variables which could influence the cord pH such as parity, use of vacuum, gestational age, maternal age, and birth weight by stepwise multiple regression analysis indicated that only the duration of second stage of labor pain had a significant relationship with cord blood pH. There is a significant fall in umbilical artery pH and bicarbonate with the presence of labor and increased duration of second stage of labor in healthy term neonates. This should be taken into consideration in evaluating neonatal well-being by cord blood pH and acid-base measurements.

Effect of intravenous β-sympathomimetic tocolysis on human fetal serum erythropoietin levels

The major stimulus for erythropoietin production is tissue hypoxia. We sought to investigate the relationship of beta-sympathomimetic administration for tocolysis and fetal serum erythropoietin. Umbilical cord blood was obtained from infants whose mothers received intravenous beta-sympathomimetic tocolysis and who were delivered at < or = 34 weeks' gestation. Serum erythropoietin was measured by radioimmunoassay. On the basis of the presumed 2- to 4-hour half-life of fetal erythropoietin, the infants were divided into two groups. In group 1 (n = 16) beta-sympathomimetic therapy was discontinued < 24 hours before delivery; in group 2 (n = 11) it was discontinued > or = 24 hours before delivery. Group 1 fetuses had significantly higher erythropoietin levels than did group 2 fetuses (37.3 vs 13.9 mU/ml, p = 0.02). The duration of beta-sympathomimetic tocolysis and the maximum infusion rate were not different. The two groups did not differ in gestational age, birth weight, route of delivery, presence of labor, or duration of first or second stage of labor. We speculate that intravenous beta-sympathomimetic tocolytic therapy stimulates fetal erythropoietin production by decreasing fetal oxygenation as a result of the reversible fetal metabolic effects of the tocolysis. These data suggest that beta-sympathomimetic tocolysis should be undertaken cautiously if fetal compromise is suspected, fetal well-being should be assessed carefully if tocolysis is undertaken, and treatment should be discontinued promptly if a clear benefit is not realized.

Maternal toxemia is associated with reduced incidence of germinal matrix hemorrhage in premature babies.

To evaluate prenatal and perinatal risk factors for development of germinal matrix hemorrhage-intraventricular hemorrhage (GMH-IVH), we conducted a prospective epidemiologic study of 449 babies whose birth weight was less than 1501 grams. This study permitted us to test our previously generated hypothesis that babies born to mothers with preeclampsia were at substantially reduced risk of developing GMH-IVH. Seventy-two (16%) of the babies in this population developed GMH-IVH. One (2.5%) of the 40 mothers with a diagnosis of preeclampsia and 71 (17.4%) of 409 mothers without preeclampsia gave birth to babies who developed GMH-IVH. GMH-IVH was seen in 6/107 (5.6%) of babies born to women with hypertension including 4/69 (5.8%) of babies born to women with pregnancy-induced hypertension, compared to 66/352 (18.8%) of babies born to mothers who did not have hypertension. Only 7.3% (8/108) of babies born to women who had proteinuria had GMH-IVH, compared to 18.3% (64/350) of babies whose mothers did not have proteinuria. GMH-IVH was seen in 5/89 (5.6%) of babies whose mothers had both hypertension and proteinuria, whereas 63/332 (19%) of babies born to mothers who lacked both factors, developed GMH-IVH. In stepwise logistic regression analysis, these significant findings were not explained by the presence of labor, postnatal acidemia, need for intubation, antenatal administration of steroids, birth weight, or gestational age. In addition, we found that maternal receipt of magnesium sulfate was associated with diminished risk of GMH-IVH even in those babies born to mothers who apparently did not have preeclampsia.(ABSTRACT TRUNCATED AT 250 WORDS)

Transverse Lie

To assess the impact of transverse lie on fetal and neonatal outcome, 14 mother and infant pairs with transverse lie were matched to 28 pairs with a vertex and 28 with a breech presentation. The control groups were matched for gestational age, route of delivery, type of anesthesia, and presence of labor. Infants in transverse lie were found to have a lower absolute arterial pH (7.21 versus 7.27, p less than 0.05) as well as more frequent severe acidosis (pH less than 7.1, 3 of 14 versus 0 of 56, p less than 0.04). Their birthweight was also less (2798 gm versus 3251 gm, p less than 0.05) and they sustained more birth trauma and long-term residual effects than either the breech (5 of 14 versus 1 of 28, p = 0.01) or vertex control groups (5 of 14 versus 2 of 28, p = 0.03). Based on these results, we recommend active intervention at 38 weeks' gestational age, via external version followed by labor induction, or failing this, cesarean delivery.

Umbilical cord cortisol and prolactin levels in preterm infants. Relation to labor and delivery.

The influence of labor and route of delivery upon the umbilical cord serum levels of cortisol and prolactin in ninety-nine preterm infants not exposed prenatally to corticosteroids was studied. Vaginally born infants (group A) presented a higher mean cord cortisol concentration than those delivered by cesarean section (group B); mean prolactin values, however, were not different between both groups. Although there was no difference in cortisol and prolactin levels between infants delivered by cesarean section after spontaneous onset of labor (group B-I) and those without labor (group B-II), the mean cortisol concentration was significantly higher in group A than in group B-I. The mean prolactin levels did not differ among all the studied groups. It is concluded that there is no association between presence of labor or route of delivery and cord serum levels of prolactin, there is no association between spontaneous preterm labor and cord cortisol values and there is an association between vaginal delivery and high cord cortisol levels in preterm infants. It is suggested that the increase in serum cortisol levels does not precede the initiation of preterm parturition but it is secondary to the stress caused by vaginal delivery.

Les trois fonctions indo-européennes, l'histoire et l'Europe féodale

The three Indo-European functions, the historian and feudal Europe Jacques Le Goff Historians, and especially mediaevalists, are taking a growing interest in the tri-functional model (the functions of religion force and fertility) in Indo-European culture as demonstrated by Georges Dumézil. In Les trois Ordres ou l'imaginaire du féodalisme, Georges Duby, studying the appearance, eclipse and re-emergence of the model between the year 1000 and the beginning of the 12th century between the Loire and the Meuse reconstructs around it an entire model of mediaeval society and sheds light on the relations between actual social structures and society's ideological models. In a bibliographical review of the subject, Gerhard Oexle examines the conceptual historical problems surrounding Adalberon of Laon's Carmen ad Rotbertum regem, recently published and translated, with commentary, by Claude Carozzi, reviving the significance of this work. In I sacerdoti, i guerrieri, i contadini, Ottavia Niccoli traces the fate of this model, through iconography, from the Middles Ages to the French Revolution. Aaron Gurevic compares the pagan Scandinavian tripartition with the Christian mediaeval tripartition. The main point concerns not the problem of the origins of this model but why, how, and for whose benefit it operated. The logic of the model suggests that the nodal points of the historical problem are : the transition from two categories to three, the relations between the first two orders and the third (promoted then demoted), the presence of labourers and work in the model, the role of kingship the transformation of tri-functionalism into quadri- functionalism. The trifunctional model is a useful tool for the study of feudal society between the 10th and the 19th centuries

On the Symmetry of Robinson Elasticities of Substitution: A Three-Factor Case

1. Along with growing public concern in environmental and urban problems, the keen attention of economists has been paid to studies of production activities which employ three (or more) factors, say, capital, labour and natural resources such as land or energy. Here again, as well as in the aggregate two-factor model of production, various formulae of elasticities of factor substitution (ES) are proved to be useful for the analysis of the internal structure of production in the works of Hicks [5], Binswanger [3], Berndt and Wood [2] and others. However, a question of symmetry of ES seems to have been totally overlooked in the literature. For example, we ask: is the ES of capital for resources always identical with the ES of resources for capital in the presence of labour as a third factor? As long as we follow Joan Robinson's original definition of ES, there is no ready-made answer to this type of question. The purpose of this note is to prove a fact that for a linearhomogeneous, three-factor production function, Morishima's elasticities of substitution (MES) as a special case of Robinson's are symmetric, i.e. cij = cji (i ] j) if and only if a given function is of the constant-elasticity-of-substitution (CES) type.