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PubMed1995

Fetal fibronectin as a marker to predict the onset of term labor and delivery.

OBJECTIVE: We examined whether the presence of fetal fibronectin in cervicovaginal secretions may be a marker to predict the onset of term labor and delivery. STUDY DESIGN: A prospective study was performed in 100 primiparous and multiparous women having reached their expected date of confinement. Fetal fibronectin was assayed by taking samples of both the cervical and vaginal mucus with two different fetal fibronectin tests. The study population was divided into women delivering within 48 hours and women giving birth > 48 hours after sampling. RESULTS: Seven patients had to be excluded from evaluation. Of the remaining 93 women, 37 were delivered within 48 hours; fetal fibronectin was detected in 30. Fifty-six women were delivered later than 48 hours; 51 of them had negative results for fetal fibronectin (positive accuracy 86%, negative accuracy 88%, p < 0.0001). CONCLUSION: Fetal fibronectin in the cervicovaginal secretions of women who have reached their expected date of confinement is a useful predictor of the onset of term labor and delivery.

Biomarkers↗

PubMed1979

Qualitative study of prostaglandins in pregnant uterine tissues: effects of estradiol- 17 beta and betamethasone.

The presence of prostaglandins (PGs) E1 and F2 alpha in extracts of endometrial, myometrial and placental samples from 19 pregnant women at term, was investigated. The tissue samples were obtained from the following group of patients: untreated, A) with onset of labor, B) without onset of labor; pre-treated (without onset of labor); C) with betamethasone, D) with estradiol-17 beta. Thin-layer chromatography determinations demonstrated PGE1 presence in all tissue samples from the four groups. On the other hand, PGF2 alpha was consistently found in placenta and endometrial samples from groups A, C, and D, but it was absent in those from group B. The results suggest a physiological role of PGF2 alpha in human parturition, and a possible influence of estrogens and corticosteroids on the appearance of this prostaglandin.

Betamethasone↗

PubMed1977

[Variations of non conjugated steroids in the amniotic fluid during the last weeks of pregnancy].

Levels of cortisol, estradiol and progesterone were measured in 172 amniotic fluid samples collected by amniocentesis during late pregnancy. An increase in cortisol and estradiol levels was observed three weeks before vaginal delivery of term and premature infants; in both types of delivery, onset of labor was spontaneous. In contrast progesterone levels were only slightly decreased in these cases.

Amniotic Fluid↗

PubMed1998

Labor ward workload waxes and wanes with the lunar cycle, myth or reality?

Objective: To test the validity of the statement "We are busy because it is getting close to the full moon" often heard on labor ward, by analysis of birth statistics in relation to lunar cycles.Method: Data for births from spontaneous onset labors for 12 lunar cycles from January 1 to December 31, 1994 was analyzed. Births resulting from induced labors were excluded. Birthrate for each day of the lunar cycle from new moon to full moon (ascending lunar phase) and from full moon to new moon (descending lunar phase) were analyzed using Pearson correlation coefficient. Birthrate at full moon was compared to that at new moon and that at mid ascending lunar phase was compared with that at mid descending lunar phase using t test.Results: There were 3706 spontaneous births during the study period. The average daily birthrate was 10.58 with standard deviation (SD) of 1.27. There was no statistically significant difference in the daily birthrate between the ascending and the descending lunar phases, r = -0.21. Statistical analysis showed no significant difference in the number of births at full moon as compared to that at new moon, P =.44. No difference was found on comparison of number of births during the mid ascending phase to that at the mid descending lunar phase, P =.84.Conclusion: Scientific analysis of data does not support the belief that the number of births increases as the full moon approaches, therefore it is a myth not reality.

Journal Article↗

PubMed1993

Successful outcome of pregnancy complicated with thyroidectomy-induced hypoparathyroidism and sudden dyspnea. A case report.

Total thyroidectomy is often accompanied with airway problem and hypoparathyroidism leading to infertility and pregnancy losses, and its effects are thus rarely reported on delivery. A patient with postoperative hypoparathyroidism carried a pregnancy to successful delivery, but suffered uncontrollable hypocalcemia and sudden respiratory distress at spontaneous labor onset. Both the fetal and maternal outcome were good. The acute deterioration in the hypoparathyroidism and airway problem at labor differed from the complications in previously reported cases.

Adenocarcinoma, Papillary↗

PubMed1983

Comparison of plasma oxytocin levels during spontaneous labor and labor induced by amniotomy, prostaglandin F2 alpha, and prostaglandin E2.

Plasma concentrations of oxytocin in nine spontaneous labors (group 1), nine amniotomy-induced labors (group 2), six prostaglandin F2 alpha-induced labors (group 3), and five prostaglandin E2-induced labors (group 4) were determined at the stages of 1 to 7 days preceding the onset of labor, onset of labor, and established labor, by means of unextracted radioimmunoassay. The levels of oxytocin in the stage preceding the onset of labor in group 1 were not significantly different from the levels of oxytocin in the corresponding stages in groups 2, 3, and 4. However, the levels of oxytocin in the stages of onset of labor and established labor in group 1 were significantly higher than those in the corresponding stages in groups 2, 3, and 4. These results suggest that oxytocin plays a leading role in the onset and progress of spontaneous labor, whereas something other than oxytocin might be involved in the labor induced by amniotomy alone or by prostaglandins.

Adult↗

PubMed1989

[Correlation of the coagulative properties of blood and the amount of postpartum blood loss].

The correlation of the intrapartum blood coagulability and the amount of postpartum blood was followed up. Blood coagulability was assessed with electric coagulography and the blood loss amount, with gravimetry. It was found that pathological postpartum blood loss occurred in the females whose labor onset was distinguished by the predominance of hypercoagulation with its subsequent intrapartum decrease. Therefore, insignificant (less than 9 per cent) increment in the blood coagulability during the labor can be regarded as a prognostic sign of pathological postpartum blood loss.

Adult↗

PubMed2005

A review of the role of proinflammatory cytokines in labor and noninfectious preterm labor.

The prevention of preterm labor has the potential to reduce newborn morbidity and mortality by decreasing the incidence of preterm birth. Half of all preterm births occur in women with no known clinical risk factors. Labor onset and progress is multifactorial, and we are just beginning to understand the role of cytokines in uterine activity. The purpose of this article is to review the role of cytokines in labor and preterm labor not associated with infection and to provide implications for research and practice.

Cytokines↗

PubMed2006

Feto-placental communication system with the myometrium inpregnancy and parturition: the role of hormones, neurohormones, inflammatory mediators, and locally active factors.

Pregnancy is a unique condition in which the conceptus is allowed to implant, survive, develop, and reach a considerable organ growth and maturation within the maternal body despite the fact that it is half genetically different from the mother. Moreover, it deeply influences the overall endocrine, metabolic, and immunological functions of the recipient mother. These objectives are accomplished through the establishment of several communication systems in which a large array of substances produced by the feto-placental unit reach specific maternal target organs and/or systems and modulate their function. The myometrium is a fundamental reproductive tissue involved in pregnancy maintenance as well as in labor onset and progression and is a potential target organ for such a communication system. An appropriate regulation of myometrial function is a key condition required for pregnancy to develop physiologically until full term is reached and for labor to start. Emerging experimental and clinical evidence suggests that a very complex feto-placental biomolecular communication system exists with the myometrium and is actively operative in the control of myometrial contractility in pregnancy and parturition through the production of a continuously increasing number of substances with endocrine, paracrine, and immunoregulatory actions.

Female↗

PubMed1988

Labor and infection. II. Bacterial endotoxin in amniotic fluid and its relationship to the onset of preterm labor.

We have previously reported the detection of endotoxin in the amniotic fluid of patients with gram-negative intraamniotic infection. Endotoxin or lipopolysaccharide is a potent biologic product capable of inducing prostaglandin release from several cell types and, therefore, may be involved in the onset of human parturition in the presence of intraamniotic infection. This article describes a technique for the quantification of endotoxin in amniotic fluid. The method uses a computer-assisted quantification of the turbidimetric reaction between the Limulus amebocyte lysate and endotoxin. Serial dilutions of Escherichia coli endotoxin in culture-negative amniotic fluid were prepared, and the samples were run in the assay. Amniotic fluid was found to enhance the reaction, and a dilution of 1:20 was required for this biologic fluid to behave similarly to pyrogen-free water. The sensitivity of this kinetic turbidimetric technique in the detection of endotoxin in amniotic fluid was 40 pg/ml. This method was applied to the quantification of endotoxin concentration in amniotic fluid in 26 patients with intraamniotic infection and premature rupture of membranes. Patients in active labor had higher concentrations of endotoxin (median = 47,514 pg/ml) than nonlaboring patients (median = 635 pg/ml) (p less than 0.025). Therefore, women with preterm labor had a higher median concentration of endotoxin in amniotic fluid than patients who were not in labor.

Amniotic Fluid↗

PubMed1993

Synthesis of oxytocin in amnion, chorion, and decidua may influence the timing of human parturition.

Despite the widespread clinical use of oxytocin (OT) as a potent and specific stimulant of labor, previous research data have not supported a role for OT in the physiology of normal human parturition. We have demonstrated synthesis of OT mRNA in amnion, chorion, and decidua using Northern blot analysis, ribonuclease protection assays, and in situ hybridization. Probes directed towards both the 3' and 5' ends of the gene have been used. Levels were highest in decidua with considerably less in chorion and amnion and very low levels in placenta. The transcript size in decidua appears to be 60-80 nucleotides smaller than the transcripts in amnion and chorion. OT gene expression in chorio-decidual tissues increased three- to fourfold around the time of labor onset. Estradiol stimulated synthesis of OT mRNA during in vitro incubation. These results support the hypothesis of a paracrine system involving OT and sex steroids within intrauterine tissues wherein significant changes could occur without being reflected in the maternal circulation. Such a paracrine system could rationalize a long-sought role for oxytocin in the physiology of human labor. These data may lead to novel approaches towards prevention or treatment or preterm labor.

Amnion↗

PubMed2001

Uterine relaxant effects of cyclooxygenase-2 inhibitors in vitro.

OBJECTIVE: To compare the effects of three cyclooxygenase-2 (COX-2) inhibitors: nimesulide, meloxicam, and celecoxib, which exhibit varying COX-2 selectivity, on contractile activity in pregnant (before and after labor) and nonpregnant human myometrial tissue in vitro. METHODS: Isometric tension recording was performed under physiologic conditions in isolated myometrial strips obtained from 33 women undergoing hysterectomy or either elective or emergency cesarean section. The effects of cumulative additions of nimesulide, meloxicam, and celecoxib (between 1 nmol/L and 100 micromol/L) on myometrial contractility were measured, and values for -log(10) EC(50) and mean maximal inhibition were compared. RESULTS: Nimesulide, meloxicam, and celecoxib exerted significant relaxant effects on contractility in nonpregnant, pregnant nonlabor, and pregnant labor myometrial strips. Values for -log(10) EC(50) values (+/- standard error of the mean) were as follows: nimesulide (nonpregnant) 5.14 +/- 0.93 (n = 6), (pregnant nonlabor) 4.91 +/- 0.75 (n = 6), and (pregnant labor) 5.84 +/- 0.35 (n = 6); meloxicam (nonpregnant) 6.53 +/- 0.57 (n = 6), (pregnant nonlabor) 4.80 +/- 0.71 (n = 6), and (pregnant labor) 5.62 +/- 0.21 (n = 6); celecoxib (nonpregnant) 6.15 +/- 0.99 (n = 6), (pregnant nonlabor) 7.08 +/- 0.98 (n = 6), and (pregnant labor) 7.25 +/- 0.99 (n = 3). Celecoxib exhibited greater potency than nimesulide or meloxicam (P < .01). The range of maximal relaxation values achieved in the three tissue types were as follows: nimesulide 68-70% (n = 18; P < .01), meloxicam 69-84% (n = 18; P < .01), and celecoxib 69-77% (n = 15; P < .01). CONCLUSION: COX-2 inhibitors exert significant relaxation in human myometrium with a similar potency in nonpregnant and pregnant (before and after labor onset) tissues. Celecoxib, a COX-2 specific inhibitor, was more potent than nimesulide or meloxicam, COX-2 preferential inhibitors.

Adult↗

PubMed2004

Intracrine control of estrogen action in human gestational tissues at parturition.

OBJECTIVE: We examined whether estrogen action in human parturition is regulated by an intracrine mechanism mediated by target tissue expression of specific 17beta-hydroxysteroid dehydrogenase (17betaHSD) isozymes that interconvert estrone (E1) and estradiol (E2), such that the onset of labor is associated with an increase in local E2 bioavailability. METHODS: The extent of 17betaHSD-1, -2, -3, -4, -5, and -7 expression (measured by quantitative reverse transcriptase polymerase chain reaction) and the capacity to interconvert E1 and E2 were compared in amnion, chorion, placenta, decidua, and myometrium obtained from women at term before (n = 6) and after (n = 6) the onset of labor. RESULTS: In chorion, abundance of 17betaHSD-1 (converts E1 to E2) mRNA decreased 2.7-fold (P <.05) in association with labor onset. In myometrium, 17betaHSD-1 and 17betaHSD-4 (converts E2 to E1) mRNAs increased two-fold and five-fold, respectively, with the onset of labor (P <.05 for each). No other statistically significant labor-associated change in 17betaHSD expression was observed. In chorion, 17betaHSD oxidative (E2 to E1) and reductive (E1 to E2) activities and the net E2 synthetic capacity increased with labor. In decidua, both activities decreased with the onset of labor, but there was no change in net E2 synthetic capacity. The capacity to interconvert E1 and E2 did not change in the other tissues. CONCLUSION: The increase in E2 synthetic capacity in the chorion might contribute to an increase in local estrogen bioactivity in association with the onset of labor. However, it cannot be explained by changes in 17betaHSD isozyme expression and is unlikely to account for the increased estrogen action at parturition. These data show that intracrine mechanisms based on 17betaHSD isozyme expression play a minor role, if any, in controlling estrogen action in gestational tissues during human parturition.

17-Hydroxysteroid Dehydrogenases↗

PubMed2004

Maternal serum interleukin-1 beta, -6 and -8 levels and potential determinants in pregnancy and peripartum.

AIMS: To measure maternal serum interleukins (IL) in pregnancy, delivery and early puerperium, and to identify their potential determinants. METHODS: Prospective longitudinal measures of serum IL-1 beta, IL-6 and IL-8 in 38 healthy pregnant women at antenatal visits, through labor and delivery, with clinical correlates (infection, vaginal hemorrhage and anemia) recorded by questionnaire. RESULTS: Pregnancy IL levels remained consistently low. IL-1 beta increased shortly before delivery, then returned to pregnant levels, except where blood loss exceeded 500 ml. IL-6 and IL-8 rose at labor onset and exceeded pregnancy levels through postpartum day three. Postpartum IL-6 was higher after non-elective cesarean section than after spontaneous delivery (P < 0.0001), and where blood loss exceeded 500 ml. IL-6 and IL-8 were higher with systemic infection during delivery (P < 0.0001) and on postpartum day one (P < 0.05); IL-8 was higher in anemia (delivery: P < 0.005; postpartum day 1: P < 0.05). Differences due to delivery mode and systemic infection remained significant after correction for other conditions. CONCLUSIONS: Labor-dependent inflammation increases all IL levels at delivery. Further studies with larger sample sizes are required to establish reference values differentiating physiology from pathology as an aid to peripartum management.

Adult↗

PubMed1994

Multistate case-control study of maternal risk factors for neonatal group B streptococcal disease. The Active Surveillance Study Group.

Risk factors for early onset disease (EOD) caused by Group B streptococci (GBS) that are the foundation of prevention guidelines were identified in studies conducted in a few hospital centers. We investigated cases of EOD identified through laboratory-based active surveillance during 1991 and 1992 in a multistate population of 17 million. Ninety-nine cases were compared with 253 controls matched for hospital, date of birth and birth weight. Prematurity (< 37 weeks of gestation) was present in 28% of cases; 53% of case mothers had rupture of membranes > 12 hours; and 48% reported intrapartum fever. The incidence of EOD in each surveillance area was higher among blacks. By multivariate analysis, case mothers were more likely than controls to have rupture of membranes before labor onset (adjusted odds ratio 8.7, P < 0.001), intrapartum fever (adjusted odds ratio 11.9, P < 0.001), and history of urinary infection during pregnancy (adjusted odds ratio 4.3, P < 0.05). Young maternal age was also associated with risk of disease. Three-fourths of case mothers had intrapartum fever, < 37 weeks of gestation and/or prolonged rupture of membranes, indicators previously used to select high risk women for intrapartum chemoprophylaxis. Our findings extend data from single hospitals and suggest prenatal screening and selective intrapartum chemoprophylaxis of high-risk mothers could potentially prevent the majority of EOD in the United States.

Age of Onset↗

PubMed2000

Labor and delivery following successful external cephalic version.

The objective of this study is to determine if successful external cephalic version is followed by an increased likelihood of prolonged labor or operative delivery. Women having a successful external cephalic version of a normal singleton fetus > or =37 weeks' gestation between January 1, 1997 and December 31, 1998 were included. Each case was matched for gestational age at delivery (+/-1 week), labor onset (spontaneous or induced), prior vaginal delivery (yes or no), and cervical dilation on admission for delivery (+/-1 cm) to the next three patients delivering a spontaneously vertex term singleton. Maternal demographics, intrapartum variables, neonatal outcomes, and route of delivery were examined. Statistical comparisons were performed by the Student's t-test or Fisher's exact test. The 38 cases and 114 controls were similar by maternal age, race, gestational age at delivery, birth weight, and insurer. There were no differences in the frequency of epidural or oxytocin use, maternal genital tract lacerations, or blood loss at delivery. Neonatal outcomes, assessed by 1- and 5-min Apgar score <7, or neonatal intensive care unit (NICU) admission did not differ between cases and controls. The labor length of patients undergoing successful version was similar to that of women laboring with spontaneously vertex fetuses (10.8 +/- 8.9 vs. 10.1 +/- 10.1 hr, p = 0.4). The frequencies of operative vaginal and cesarean delivery in cases did not differ from those of controls (3/38 vs. 1/114, p = 0.56 and 4/38 vs. 8/114, p = 0.51, respectively.) Labor duration and delivery route following successful external cephalic version do not differ from women with spontaneously vertex fetuses.

Adult↗

PubMed2000

Twin vaginal birth after cesarean.

OBJECTIVE: To determine both success rate and maternal-fetal outcome of vaginal birth after cesarean in twin gestations. METHODS: We identified all women from a single center attempting vaginal birth of twins after cesarean from 1988-98. Twin pairs were excluded for delivery < or = 25 weeks gestation, monoamnionicity, nonvertex twin A, or major anomaly or death of either twin. Cases were matched to the next three consecutive twin gestations attempting vaginal delivery without a prior cesarean. Variables matched were gestational age at delivery (+/- 1 week), presentations of both fetuses, labor onset (spontaneous or induced), and prior vaginal delivery (yes or no). The primary outcome was successful vaginal delivery of both fetuses. Secondary maternal outcomes included chorioamnionitis, hemorrhage requiring transfusion, hysterectomy, uterine rupture, and length of stay. Neonatal outcomes included one and five minute Apgars, NICU admission, and length of NICU stay. RESULTS: Twelve parturients were matched to 36 controls. There were no differences between the groups with respect to maternal demographics, intrapartum variables, fetal genders, birthweights, or chorionicity. Women with a prior cesarean (10/12) delivered both twins vaginally compared to 31/36 parturients without a prior cesarean (P = 1.0). There were no differences between cases and controls with respect to maternal morbidity (1/12 vs 4/36, P = 1.0), or postpartum stay (2.5 +/- 1.0 vs 2.5 +/- 2.3 days, P = .25). Neonatal outcomes were similar by birth order, except that second-born twins of cases had significantly longer NICU stays than controls (22.7 +/- 3.8 vs 10.4 +/- 7.8 days, P = .04). CONCLUSION: Twin trial of labor after cesarean is associated with a high success rate of vaginal delivery but may be associated with a more lengthy NICU stay for the second twin.

Cesarean Section↗

PubMed1991

[Levels of endothelin-1 in maternal and cord plasma during pregnancy and delivery].

In order to elucidate the possible involvement of endothelin-1 (ET-1) in the development of the feto-placental unit, plasma concentrations of immunoreactive ET-1 during pregnancy and delivery were measured in the current study. Forty-four pregnant women (8 in the 1st trimester, 8 in the 2nd trimester, 12 in the 3rd trimester and 16 at delivery), 6 at 1 month postpartum and 14 non-pregnant women volunteered to participate in this study. Plasma levels of immunoreactive ET-1 in all subjects were measured by specific radioimmunoassay. Plasma cortisol, prolactin and oxytocin levels during delivery were also measured by RIA. Although plasma ET-1 levels did not change during the 1st (1.3 +/- 0.4 pg/ml, mean +/- S.E.M., n = 8) or 2nd (1.7 +/- 0.3 pg/ml, n = 8) trimester, they were significantly (p less than 0.05) higher in the 3rd trimester (2.6 +/- 0.3 pg/ml, n = 12) than those of the non-pregnant controls (1.7 +/- 0.3 pg/ml, n = 14) and returned to the control levels within 1 month post-partum (1.8 +/- 0.1 pg/ml, n = 6). Maternal ET-1 levels before labor onset (2.3 +/- 0.4 pg/ml, n = 16), at delivery (3.0 +/- 0.7 pg/ml) and 24 hours post-partum (2.7 +/- 0.5 pg/ml) showed no significant differences among them. On the other hand, ET-1 levels in cord plasma (7.0 +/- 1.2 pg/ml) were significantly higher (p less than 0.05) than those in maternal plasma. Furthermore, there were no significant correlations between plasma ET-1 levels and those of other hormones (cortisol, prolactin and oxytocin) during delivery. From these results, we concluded that maternal plasma ET-1 levels significantly increased in the last trimester and returned to non-pregnant levels within one month post-partum.

Adult↗