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PubMedDate not supplied

Effects of intrathecal sufentanil on plasma oxytocin and cortisol concentrations in women during the first stage of labor.

BACKGROUND AND OBJECTIVES: Intrathecal sufentanil provides analgesia comparable to epidural bupivacaine for the first stage of labor. Both epidural local anesthetics and intrathecal opioid reduce some parameters of the neuroendocrine response to labor pain and the reflex release of oxytocin in animals. In humans, epidural local anesthetics only reduce the spurt release of oxytocin. This study compared the effect of intrathecal sufentanil and epidural bupivacaine administration on the plasma concentration of oxytocin and cortisol in women with labor pain during the first stage of labor. METHODS: Thirty healthy parturients requesting analgesia were enrolled in this randomized and open-label study. Each patient was in spontaneous labor at greater than 5 cm cervical dilatation. Using a combined spinal and epidural technique, patients received either intrathecal sufentanil 10 microg (SUF = intrathecal sufentanil group) or epidural plain bupivacaine 0.25%, 12 mL (BUPIV = epidural bupivacaine group). Analgesia was assessed using a visual analog scale, and blood samples for oxytocin and cortisol plasma concentration measurements were collected immediately before analgesia and 15, 30, 60, and 90 minutes after induction of the analgesia. Plasma cortisol and oxytocin concentrations were determined by specific radioimmunoassay. The values were expressed as mean +/- SEM. RESULTS: Intrathecal sufentanil provided faster and more complete analgesia within 15 and 30 minutes of its administration, compared with epidural bupivacaine. Plasma oxytocin concentrations were similar in the 2 groups before analgesia (7.24 +/- 2.1 and 6.6 +/- 3.1 pg/mL SUF and BUPIV, respectively). It decreased significantly in the SUF and increased in the BUPIV after analgesic administration. Cortisol concentrations were elevated in both groups before analgesia (51.6 +/- 5.3 and 54.2 +/- 4.8 microg/dL SUF and BUPIV, respectively). Both analgesic treatments significantly decreased the plasma cortisol levels. CONCLUSIONS: Intrathecal sufentanil analgesia decreases plasma concentrations of oxytocin and cortisol in women with labor pain during the first stage of labor, but epidural bupivacaine only reduced the cortisol concentration.

Adult↗
PubMed2004

Mode of delivery in pregnancies with premature rupture of membranes at or before term following induction of labor with vaginal prostaglandin E2.

Our aim was to evaluate the mode of delivery in pregnancies complicated with premature rupture of the membranes (PROM) at or before term following induction of labor with vaginal application of prostaglandin E2 (PGE2), and to identify possible predictors leading to cesarean section (CS). The study sample consisted of 220 women with term-PROM who did not enter spontaneous labor after 24 hours of expectant management and 42 with preterm (P)-PROM, who underwent labor induction with vaginal PGE2. Findings were compared with 115 women admitted for elective induction of labor, and 510 women with normal spontaneous-onset labor. There were no between-group differences in gravidity, parity, nulliparity rate, or number of PGE2 tablets used. Women with P-PROM were admitted at 34.6 +/- 2.4 weeks gestation, and delivered at 36.1 +/- 1.6 weeks (mean interval, 5.0 +/- 7.9 days; range, 0.5 to 40 days). The rate of CS was different only between the term-PROM (18.6%) and spontaneous onset of labor (9%) groups (odds ratio, 2.08; 95% confidence interval, 1.4 to 3.4). The rate of low 5-minute Apgar score (< 7) was similar in all groups, but the incidence of nonreassuring fetal heart rate pattern leading to CS was significantly lower in the PROM groups. A logistic regression model and forward likelihood analysis in the PROM groups yielded parity, higher number of PGE2 tablets used, and higher birth weight as independent and significant variables associated with increased risk of CS. Using our management protocol, 36.4% and 20.4% of women with term-PROM and P-PROM, respectively, required labor induction with PGE2, which was successful in more than 80% of cases, with no apparent serious maternal or fetal complications.

Administration, Intravaginal↗
PubMed1994

Intracervical prostaglandin E2 for induction of labor in patients with premature rupture of membranes and an unripe cervix.

The efficacy and safety of intracervical prostaglandin E2 (PGE2) gel for induction of labor in patients with premature rupture of the membranes (PROM) at term and with an unripe cervix were evaluated. Fifty-two patients who did not start labor 6 to 12 hours after PROM and who had an unripe cervix were randomized to one of two management protocols. Patients randomized to PGE2 received a single intracervical application of 0.5 mg PGE2. Patients randomized to the conservative protocol were managed expectantly for 24 hours. If labor was not established 6 hours after randomization in patients receiving PGE2 or 24 hours after PROM in patients managed expectantly, labor was induced with intravenous oxytocin. Of the patients receiving PGE2, 93% began labor after a single application, and the mean interval between prostaglandin application and delivery was 6.6 hours. In the conservative group, only 57% began labor within 24 hours, and more than half of them required augmentation with oxytocin. The mean latency between PROM and delivery was 15 hours in patients managed with PGE2 and 30 hours in patients managed conservatively (P < 0.01). There were no complications and pregnancy outcome was similar in the two groups. Intracervical PGE2 is safe and effective for inducing labor in patients with PROM and an unfavorable cervix.

Adult↗
PubMed1992

Induction of labor as compared with serial antenatal monitoring in post-term pregnancy. A randomized controlled trial. The Canadian Multicenter Post-term Pregnancy Trial Group.

BACKGROUND: The rates of perinatal mortality and neonatal morbidity are higher for post-term pregnancies than for term pregnancies. It is not known, however, whether the induction of labor results in better outcomes than does serial fetal monitoring while awaiting spontaneous labor. METHODS: We studied 3407 women with uncomplicated pregnancies of 41 or more weeks' duration. The women were randomly assigned to undergo induction of labor or to have serial antenatal monitoring and spontaneous labor unless there was evidence of fetal or maternal compromise, in which case labor was induced or cesarean section was performed. In the induction group, labor was induced by the intracervical application of prostaglandin E2. Serial antenatal monitoring consisted of counts of fetal kicks, nonstress tests, and assessments of amniotic-fluid volume. The outcomes we measured were the rates of perinatal mortality, neonatal morbidity, and delivery by cesarean section. RESULTS: Among the 1701 women in the induction group, 360 (21.2 percent) underwent cesarean section, as compared with 418 (24.5 percent) of the 1706 women in the monitoring group (P = 0.03). This difference resulted from a lower rate of cesarean section performed because of fetal distress among the women in the induction group (5.7 percent vs. 8.3 percent, P = 0.003). When two infants with lethal congenital anomalies were excluded, there were no perinatal deaths in the induction group and two stillbirths in the monitoring group (P not significant). The frequency of neonatal morbidity was similar in the two groups. CONCLUSIONS: In post-term pregnancy, the induction of labor results in a lower rate of cesarean section than serial antenatal monitoring; the rates of perinatal mortality and neonatal morbidity are similar with the two approaches to management.

Adult↗
PubMed1996

Induction of labor compared with expectant management for prelabor rupture of the membranes at term. TERMPROM Study Group.

BACKGROUND: As the interval between rupture of the fetal membranes at term and delivery increases, so may the risk of fetal and maternal infection. It is not known whether inducing labor will reduce this risk or whether one method of induction is better then another. METHODS: We studied 5041 women with prelabor rupture of the membranes at term. The women were randomly assigned to induction of labor with intravenous oxytocin; induction of labor with vaginal prostaglandin E2 gel; or expectant management for up to four days, with labor induced with either intravenous oxytocin or vaginal prostaglandin E2 gel if complications developed. The primary outcome was neonatal infection. Secondary outcomes were the need for cesarean section and women's evaluations of their treatment. RESULTS: The rates of neonatal infection and cesarean section were not significantly different among the study groups. The rates of neonatal infection were 2.0 percent for the induction-with-oxytocin group, 3.0 percent for the induction-with-prostaglandin group, 2.8 percent for the expectant-management (oxytocin) group, and 2.7 percent for the expectant-management (prostaglandin) group. The rates of cesarean section ranged from 9.6 to 10.9 percent. Clinical chorioamnionitis was less likely to develop in the women in the induction-with-oxytocin group than in those in the expectant-management (oxytocin) group (4.0 percent vs. 8.6 percent, P<0.001), as was postpartum fever (1.9 percent vs. 3.6 percent, P=0.008). Women in the induction groups were less likely to say they liked "nothing" about their treatment than those in the expectant-management groups. CONCLUSIONS: In women with prelabor rupture of the membranes at term, induction of labor with oxytocin or prostaglandin E2 and expectant management result in similar rates of neonatal infection and cesarean section. Induction of labor with intravenous oxytocin results in a lower risk of maternal infection than does expectant management. Women view induction of labor more positively than expectant management.

Adult↗
PubMed2000

Transvaginal ultrasonographic cervical measurement as a predictor of successful labor induction.

OBJECTIVE: Our purpose was to compare transvaginal cervical measurement and the Bishop score as indicators of duration of labor and successful induction of labor at term. STUDY DESIGN: This prospective observational study recruited women with singleton gestations scheduled for induction of labor at > or =37 weeks. Transvaginal ultrasonographic measurement of cervical length was performed and the Bishop score was determined, each by operators masked to the other measurement. Data were collected on parity, gestational age, mode of delivery, induction agent, induction-to-delivery interval, Bishop score, and cervical length measurement. RESULTS: A total of 77 women were analyzed. Vaginal delivery occurred in 69%. Both Bishop score and cervical length showed linear correlation with duration of labor (R(2) = 0.43, P <. 001; R(2) = 0.48, P <.001; respectively). Women with cervical length <3.0 cm had shorter labors (P <.001) and were more likely to be delivered vaginally (P <.001). Women with a Bishop score >4 also had shorter labors and were more likely to be delivered vaginally, with similar P values. A logistic regression model identified cervical length and parity as the only independent predictors of vaginal delivery. CONCLUSIONS: Both ultrasonographically measured cervical length and Bishop score predict duration of labor and likelihood of vaginal delivery. However, only cervical length and parity were independent predictors of mode of delivery.

Cervix Uteri↗
PubMed2000

Effect of vaginal pH on efficacy of misoprostol for cervical ripening and labor induction.

OBJECTIVE: We sought to evaluate whether vaginal pH has an effect on the relative efficacy of misoprostol for cervical ripening and labor induction. STUDY DESIGN: Thirty-seven gravid women with an unfavorable cervix and indication for labor induction were enrolled in this prospective, double-blind, observational study. Baseline assessments of cervicovaginal pH and Bishop score were made at the time of enrollment by an independent examiner. All patients received 50 microg misoprostol intravaginally every 6 hours for 12 hours. After the initial 12 hours of preinduction, a repeat Bishop score assessment was made by the same initial examiner. Patients not in active labor at 12 hours were placed on a standardized oxytocin induction regimen. Labor was managed by the on-call obstetric team, who remained blinded to pH assessment. Clinical outcomes were evaluated. Statistical analyses were made by the Student t test, the Fisher exact test, and linear regression analysis. RESULTS: Average initial vaginal pH was 4.8 +/- 0.5 (range, 3.5-7.0) for the study cohort. No significant differences were noted between those patients with low vaginal pH (< or =4.5) compared with those with high pH vaginal (>4.5) with respect to maternal age, parity, gestational age, or initial Bishop score. Similarly, Bishop score change over preinduction interval (5.6 vs 4.9), time to active labor (16.3 vs 17. 1 hours), time to complete dilatation (20.0 vs 19.9 hours), and time to delivery (21.0 vs 21.6 hours) were not significantly different between the low and high pH groups, respectively. Linear regression analysis revealed no significant association between vaginal pH and Bishop score change during preinduction interval, time to active labor, time to complete dilatation, or time to delivery. CONCLUSION: Vaginal pH does not appear to influence the efficacy of intravaginally administered misoprostol for cervical ripening and labor induction.

Adult↗
PubMed2000

Elevations of group II phospholipase A2 concentrations in serum and amniotic fluid in association with preterm labor.

OBJECTIVE: The purpose of this study was to determine whether the elevation of secretory group II phospholipase A(2) concentration in the serum and amniotic fluid in preterm labor is associated with intrauterine inflammation. STUDY DESIGN: Serum and amniotic fluid were collected from women with preterm delivery (<37 weeks' gestation; n = 38) and term delivery (n = 20). Phospholipase activity was measured with a highly sensitive system that was based on reverse-phase high-performance liquid chromatographic separation of 9-anthracenylmethyl derivatives of fatty acids released by phospholipase A(2). The concentrations of immunoreactive isozymes (group I or II) of secretory phospholipase A(2) were assayed with a radioimmunoassay kit with a monoclonal antibody against human pancreatic phospholipase A(2) and splenic IIA phospholipase A(2). Localization of immunoreactive group II phospholipase A(2) in the amniotic membrane was determined by immunostaining visualized with the Vectastain ABC (Vector Laboratories, Inc, Burlingame, Calif) method. RESULTS: Enzymatic activities of phospholipase A(2) in the serum and amniotic fluid specimens obtained from patients in preterm labor with chorioamnionitis were significantly higher than those in specimens from patients in term labor. Significant elevations of phospholipase A(2) activities were observed in patients with preterm labor without histologically evident chorioamnionitis. The activity of phospholipase A(2) was clearly correlated with the concentration of the immunoreactive group II phospholipase A(2). Group II phospholipase A(2) was localized in amniotic cells obtained from patients with a pathologically determined diagnosis of chorioamnionitis. The predictive value for chorioamnionitis of the group II phospholipase A(2) concentration was relatively higher than the predictive values of the concentrations of C-reactive protein and interleukins 6 and 8. CONCLUSION: Significant elevations of group II phospholipase A(2) concentrations were detected in the serum and amniotic fluid of women with preterm labor. Group II phospholipase A(2) concentration may be a useful indicator for preterm labor, and phospholipid metabolism is certainly activated both in preterm labor and in apparent inflammatory diseases.

Amniotic Fluid↗
PubMed2001

Phenotypic and metabolic characteristics of maternal monocytes and granulocytes in preterm labor with intact membranes.

OBJECTIVE: Experimental and clinical studies support a role for the fetus in the control of the onset of labor. Fetal systemic inflammation, but not a maternal inflammatory response, has been linked to the onset of preterm labor and delivery on the basis of the determination of inflammatory cytokines in fetal and maternal blood. We propose that parturition requires fetomaternal cooperation and that inflammation is an integral part of the parturitional process. This study used flow cytometry, a sensitive technique for the detection of intravascular inflammation, to assess whether maternal inflammation is present in preterm labor. STUDY DESIGN: A prospective cross-sectional study was performed including patients with preterm labor (n = 55) and women with normal pregnancy (n = 50). Intravascular inflammation was studied by using flow cytometry. Maternal blood was assayed to determine granulocyte and monocyte phenotype by using monoclonal antibodies, which included the following cluster of differentiation (CD) markers: CD11b, CD14, CD15, CD16, CD18, CD49d, CD62L, CD64, CD66b, and HLA-DR. Oxidative burst and generation of basal intracellular oxygen radical species were assessed. Statistical analysis was conducted with the use of nonparametric methods. A P value of <.01 was considered statistically significant. RESULTS: Preterm labor was associated with a significant increase in the median mean channel brightness of CD11b, CD15, and CD66b on granulocytes and median mean channel brightness of CD11b and CD15 on monocytes. The ratio of oxidative burst over basal intracellular oxygen radical species in both granulocytes and monocytes was increased in preterm labor (P <. 01). CONCLUSION: Preterm labor with intact membranes is associated with phenotypic and metabolic changes of maternal granulocytes and monocytes.

Adult↗
PubMed2002

Pharmacokinetics of ionized versus total magnesium in subjects with preterm labor and preeclampsia.

OBJECTIVE: Intravenous magnesium sulfate is widely used in obstetrics for the treatment of both preterm labor and preeclampsia. Although therapeutic levels of total magnesium have been proposed, the levels remain controversial. Because the active form of magnesium is the free or ionized form, it is essential to determine whether ionized magnesium and total magnesium levels are highly correlated in vivo. We sought to examine the correlation between ionized magnesium and total magnesium under basal and therapeutic conditions and to define the initiation and elimination pharmacokinetics of both forms during intravenous magnesium sulfate infusion. STUDY DESIGN: Twenty-four singleton pregnant patients who were candidates for magnesium sulfate were studied (preterm labor, 15; preeclampsia, 9). Serial blood samples were taken before the magnesium sulfate infusion, during the first 4 hours after the initiation of magnesium sulfate infusion and for 4 hours after the discontinuation of the infusion. RESULTS: Baseline levels of total magnesium and ionized magnesium were not different between patients with preterm labor and with preeclampsia. Among patients with preeclampsia, although not patients with preterm labor, the initial apparent volume of distribution was significantly smaller for total magnesium than for ionized magnesium (16,397 +/- 1441 vs 23,856 +/- 2745 mL, respectively; P =.03), and the elimination half-life was greater for total magnesium as compared to ionized magnesium (707 +/- 160 vs 313 +/- 29 minutes;P <.05). Linear regression analysis demonstrated a lack of correlation between ionized magnesium and total magnesium during the pretreatment period and during the steady state infusion for both preterm labor and preeclampsia. CONCLUSION: The measurement of total magnesium may not be adequate for the titration of therapeutic magnesium infusions in patients with preeclampsia or preterm labor because of the lack of correlation between total magnesium and the physiologically active ionized magnesium. Further studies may determine whether the measurement of ionized magnesium is a superior method for following the adequacy and safety of the treatment of preeclampsia and preterm labor.

Adult↗
PubMed2003

Prediction of successful induction of labor at term: role of clinical history, digital examination, ultrasound assessment of the cervix, and fetal fibronectin assay.

OBJECTIVE: The purpose of this study was to evaluate whether biochemical (fetal fibronectin assay) or biophysical (cervical assessment by transvaginal ultrasound) tests may have more value than digital examination in predicting successful induction of labor at term. STUDY DESIGN: The study enrolled prospectively 134 women undergoing labor induction at term caused by several obstetric conditions. All participants submitted to digital examination, fetal fibronectin assay, and transvaginal ultrasound for measurement of the cervical length and detection of funneling. The performance of each test in predicting delivery within 24 hours of labor induction was evaluated. Cox multiple regression analysis was performed to identify, among clinical and laboratory tests, which variables were independently associated with the duration of the latent phase and with the total duration of induced labor. RESULTS: The likelihood ratios for positive results (predicting that delivery would occur within 24 hours) were 6.61 (95% CI, 1.7-25.8) for a positive obstetric history (previous vaginal delivery), 2.61 (95% CI, 1.6-4.3) for a "favorable" digital examination, 1.41 (95% CI, 0.9-2.2) for a positive fetal fibronectin test, 1.61 (95% CI, 0.9-3.0) for cervical length, and 2.20 (95% CI, 1.1-4.4) for the presence of funneling at transvaginal ultrasound. The likelihood ratios for negative results were 1.81 (1.3-2.5) for obstetric history, 4.34 (2.5-7.7) for digital examination, 1.41 (0.9-2.1) for fetal fibronectin, 1.29 (1.0-1.7) for cervical length, and 1.48 (1.1-2.0) for funneling. On multiple regression, the only variables independently associated with the duration of the latent phase and with the total duration of induced labor were obstetric history and digital examination. CONCLUSION: Only obstetric history and digital examination predicted accurately vaginal delivery within 24 hours and were independently associated with labor duration. Fetal fibronectin and ultrasound measurements failed to predict accurately the outcome of induced labor.

Adult↗
PubMed2006

The need for a new outlook on labor monitoring.

Fetal heart rate monitors, including the newer pulse-oximetry and STAN monitors, are designed to detect fetal distress that affects less than 1% of women in labor. Non-progressive labor is a much more common disorder than fetal distress, with approximately 50% of women in labor requiring oxytocin. Current technology assessing labor progress is subjective and inaccurate. There is a need for objective and accurate technology to measure labor progress and the effect it may have on managing labor and, specifically, non-progressive labor.

Female↗
PubMed2002

Post-term pregnancy: should induction of labor be considered before 42 weeks?

OBJECTIVE: To determine the occurrence of maternal and fetal complications in low-risk pregnancies beyond 39 weeks and to re-evaluate the acceptable cut-off (42 weeks) for induction of labor. STUDY DESIGN: A total of 36 160 low-risk pregnancies with reliable dating of gestational age (last menstrual period and early ultrasound examination) were evaluated retrospectively for fetal and maternal complications, including non-progressive labor, cervical tear, retained placenta, postpartum hemorrhage, vacuum delivery, Cesarean section, macrosomia, meconium-stained amniotic fluid, non-reassuring fetal heart rate monitoring and ante-, intra- and postpartum death. Pregnancy outcomes at different gestational ages were compared using univariate and multivariate analysis and receiver operator curves. RESULTS: The rates of non-progressive labor stage I and II, retained placenta, vacuum delivery, Cesarean section, macrosomia, meconium-stained amniotic fluid and non-reassuring fetal heart rate monitoring were found to be significantly higher with increasing gestational age in the univariate analysis. These parameters were evaluated using multivariate analysis and the following were found to be significantly higher: non-progressive labor stage I and II, macrosomia, meconium-stained amniotic fluid and Cesarean section. Statistical analysis (receiver operator curves) showed that the most significant rise in the risk for non-progressive labor occurred after 42 completed weeks of gestation, and after 41 completed weeks for macrosomia, meconium-stained amniotic fluid and Cesarean section. CONCLUSIONS: The rates of non-progressive labor stage I and II, meconium-stained amniotic fluid, macrosomia and Cesarean section were significantly higher with increasing gestational age. In order to decrease the rate of macrosomia, meconium-stained amniotic fluid and Cesarean section, we suggest that induction of labor should be considered before 42 weeks.

Amniotic Fluid↗
PubMed1995

Maternal asthma and idiopathic preterm labor.

Previous studies suggest that women with asthma are at increased risk of preterm birth. Moreover, drugs (especially beta-agonists) used to treat asthma are also used to treat preterm labor. The authors carried out a case-control study of 555 women from three hospital centers with idiopathic preterm labor (< 37 weeks), including two overlapping (i.e., non-mutually exclusive) subsamples: cases with early idiopathic preterm labor (< 34 weeks) and cases with idiopathic recurrent preterm labor (< 37 weeks plus a previous history of preterm delivery or second-trimester miscarriage). Controls were matched to cases according to race and smoking history prior to and during pregnancy. All subjects responded in person to questions about atopic, respiratory, obstetric, and sociodemographic histories. Subjects in the early and recurrent preterm labor subsamples were also asked to undergo spirometric testing with methacholine challenge 6-12 weeks after delivery. Cases were significantly more likely to report histories of asthma symptoms and physician-diagnosed asthma (matched odds ratios of 2-3) than controls, particularly those cases with recurrent preterm labor. No significant associations were observed, however, with methacholine responsiveness. These results could not be explained by residual confounding by smoking or other variables, nor by selective recall of asthma symptoms and histories by cases. Women with asthma are at increased risk of idiopathic preterm labor. The fact that no such association was seen with methacholine responsiveness suggests that nonatopic, noncholinergic mechanisms may link bronchial and uterine smooth muscle lability.

Adult↗
PubMed2005

Expression of alpha5 integrin (Itga5) is elevated in the rat myometrium during late pregnancy and labor: implications for development of a mechanical syncytium.

The underlying mechanisms controlling uterine contractions during labor are still poorly understood. Integrins are heterodimeric, transmembrane receptors composed of alpha and beta subunits that can be found in focal adhesions. Because these structures play an important role in the regulation of smooth muscle contractility and cell adhesion, we hypothesized that alpha5 integrin mRNA (Itga5) and protein (ITGA5) expression would be induced in the rat myometrium during late pregnancy and labor. Itga5 mRNA expression was significantly increased (P < 0.05) from Day 17 to labor, noticeably decreasing 1 day postpartum (PP). Immunoblot analysis illustrated a continual increase in ITGA5 levels during pregnancy, labor, and PP, with levels reaching significance at labor (P < 0.05). Analysis of ITGA5 expression by immunocytochemistry demonstrated that it is primarily localized to myometrial cell membranes in the longitudinal muscle layer of the myometrium from before pregnancy to Day 6, and in both the longitudinal and circular muscle layers from Day 15 to PP. Treatment of late-pregnant rats with progesterone blocked labor and resulted in sustained expression of Itga5 mRNA expression to Day 24. In addition, immunocytochemistry experiments showed ITGA5 was detectable at higher levels in cell membranes of both myometrial layers in progesterone-treated animals on Days 23 and 24, compared with vehicle controls. We propose that ITGA5, with its sole known partner, ITGB1, may be important in promoting cellular cohesion during late pregnancy. This process may aid the development of a mechanical syncytium for efficient force transduction during the sustained, coordinated, and powerful contractions of labor.

Animals↗
PubMed1998

Thrombospondin-1 expression in human myometrium before and during pregnancy, before and during labor, and in human myometrial cells in culture.

The activation of latent transforming growth factor beta (L-TGFbeta) is essential for the action of TGFbeta, which, in turn, is involved in the regulation of expression of some progesterone-responsive genes. One mechanism by which TGFbeta is activated involves thrombospondin (TSP), a protein that binds extracellular proteins. Immunoreactive TSP (irTSP) protein and TSP-1 mRNA in myometrial tissues of ovulatory and pregnant women were localized by immunohistochemistry and in situ hybridization. IrTSP and TSP-1 mRNA were randomly distributed in myometrial smooth muscle cells of some, but not all, tissues of pregnant women at term before labor; but in some areas of most of these tissues, irTSP was intense and commonly localized extracellularly. Intense irTSP and TSP-1 mRNA in myocytes were more common in myometrium during labor. In myometrium from ovulatory women (n = 26), irTSP was localized primarily in vascular smooth muscle cells and was detected occasionally in scattered myocytes. Little TSP-1 mRNA was demonstrable by in situ hybridization in vessels or myocytes of myometrial tissue from ovulatory women (n = 7). By Northern analysis of total RNA, TSP-1 mRNA was detected in myometrial tissue of pregnant women and in human myometrial smooth muscle cells in culture. The levels of TSP-1 mRNA in myometrial tissues of pregnant women during labor (n = 18) were greater than those in myometrium at > 37 wk gestation before labor began (n = 25, p < 0.001). The ratios of TSP-1 to glyceraldehyde 3-phosphate dehydrogenase mRNAs in 3 myometrial tissues during oxytocin-induced labor were not statistically different from those in myometrium during spontaneous labor but were greater than those in myometrium before labor (p < 0.05). The level of TSP-1 mRNA in confluent human myometrial cells in culture was relatively high, was increased by treatment with fetal bovine serum, and was decreased by treatment with platelet-derived growth factor or activators of adenylyl cyclase or protein kinase C. Myometrial cells in culture constitute a useful model for studying the regulation of TSP-1 gene expression in human myometrium.

Adult↗
PubMed2001

Intensity of labor pain and cesarean delivery.

Some authors have suggested that the intensity of labor pain may be related to labor dystocia. We performed a secondary analysis of a previously published randomized investigation of the effects of epidural analgesia during labor compared with patient-controlled IV meperidine on cesarean delivery. Two-hundred-fifty-nine women who received patient-controlled IV meperidine were identified for analysis. All women were in spontaneous labor with a singleton, term gestation. Women requiring 50 mg or more of meperidine per hour during labor were compared with those who required <50 mg/h. In addition, their pain scores (visual analog scale) were compared before and after analgesia administration. Pain scores were significantly higher in women requiring 50 mg/h of meperidine (8.7 vs 8.0, P = 0.05), and their labors tended to be longer (9 vs 5 h, P = 0.09). More cesarean deliveries for obstructed labor were performed in women requiring >50 mg/h of meperidine (14% vs 1.4%, P = 0.001). Neonatal outcomes were similar in the two groups.

Adult↗
PubMed1983

Effects of epidural anesthesia during labor on maternal plasma beta-endorphin levels.

Plasma beta-endorphin (beta-EP) was measured in 48 women. Twenty-three were in labor. In 13 of the 23 patients in labor, beta-EP was determined prior to and after complete onset of epidural anesthesia, and in 10 women, who served as controls, prior to and after injection of saline into the epidural space as part of the loss of resistance technique, but before injection of the local anesthetic. Venous blood also was obtained for plasma beta-EP determinations from 10 healthy non-pregnant women and from 15 patients scheduled for elective repeat cesarean section and who were not in labor. Human beta-EP was determined by radioimmunoassay following silicic acid extraction of plasma samples and separation of the beta-EP fraction by gel chromatography. In the 10 non-pregnant volunteers, plasma beta-EP averaged 11.3 +/- 1.5 fmol/ml (mean +/- SE) as compared with 43.7 +/- 6.5 fmol/ml observed in the 15 women with term pregnancies who were not in labor (P less than 0.005). In the 13 patients in labor who underwent epidural anesthesia, plasma beta-EP concentrations decreased (P less than 0.005) from 54.5 +/- 9.0 to 28.2 +/- 3.5 fmol/ml, whereas there was no significant change in plasma beta-EP levels in the 10 controls who averaged 64 +/- 20.5 and 55.8 +/- 13.6 fmol/ml prior to and following saline injection. These data confirm that plasma beta-EP levels are significantly higher in women with term pregnancies in labor than in non-pregnant women and also demonstrate that epidural anesthesia during labor is accompanied by a significant decrease in maternal plasma beta-EP concentrations.

Adult↗