Normal Spontaneous Labor Research Articles

Association between Intrapartum Cardiotocography and Umbilical Cord Blood pH in Term Pregnancies: A Cross-sectional Study in a Tertiary Care Centre, Kolkata, India

Introduction: Labour, a physiological process for majority of foetuses, often acts as a challenge to foetal reserves causing foetal hypoxia. Foetal monitoring with intrapartum cardiotocography is an important tool to enable timely intervention to reduce adverse neonatal outcomes like postnatal cerebral palsy. Aim: To determine an association between cardiotocography tracing and umbilical artery cord blood pH in term pregnancies in labour where the influence of drugs and the presence of other comorbid medical/obstetric adverse outcomes have been ruled out. Materials and Methods: This cross-sectional, hospital-based, observational study involved singleton uncomplicated term pregnancies with a normal baseline cardiotocography and spontaneous labour onset and progression admitted to the labour ward of R.G. Kar Medical College and Hospital, Kolkata, West Bengal, India. Intrapartum continuous cardiotocography traces were recorded and those showing abnormal traces were documented and delivery expedited within two hours. Total of 90 such consecutive women were included in the study and umbilical arterial cord blood sample was taken for all these pregnancies immediate postpartum. Cardiotocography traces were then statistically compared with cord blood parameters and the findings were computed using Statistical Package for the Social Sciences (SPSS) software version 22.0. Results: Out of 90 participants the mean age was 24.21±3.43 years, most (43, 47.8%) of them were in between 21 to 25 years. Of the abnormal traces, 51 (56.7%) were NICE Category II (Suspicious) and 39 (43.3%) were NICE category III (pathological). Cord blood analysis revealed that 40% had a pH<7, 44.4% had blood lactate levels above 6 mmol/L and another 47.7% had a base deficit ≥12 mmol/L. On crosstabulation and Chi-square analysis, these were all found to be statistically significant (p-value <0.05). Abnormalities of Foetal Heart Rate (FHR) and baseline variability had higher Odds ratio of predicting umbilical artery acidemia with Odd’s ratio for baseline variability abnormality as high as 2.768. Conclusion: Although there has been a rising trend towards operative deliveries, the overall incidence of neonatal morbidity due to cerebral palsy is still on the rise. Cardiotocography can be a very important tool to identify neonatal acidosis in “at risk” foetuses and helps in timely intervention giving long term best outcomes.

Quality of intrapartum care for healthy women with spontaneous onset of labour in Rwanda: A health facility-based, cross-sectional study

ObjectiveTo investigate the quality of intrapartum care provided at Rwandan healthcare facilities to women undergoing normal pregnancy and spontaneous full-term labour. MethodsA cross-sectional study was conducted over eight weeks during 2014–2015 in 18 healthcare facilities in Kigali City and the Northern Province: eight health centres, seven district hospitals, one provincial hospital, one private hospital, and one referral hospital. Data were collected from medical records and a questionnaire including the Bologna score with its five variables: presence of a companion, use of partograph, no augmentation of labour, birth in a non-supine position, and skin-to skin contact. ResultsAmong the 435 women who fulfilled the inclusion criteria during the study period, mean age was 27.4 years and 41.8% were primiparous. The assisting healthcare professionals were midwives (49.4%), nurses (28.8%), and physicians (22%), and birth occurred at health centres (29%), district hospitals (40%), and the referral hospital (31%). Mean Bologna score was 2.03 of the maximum 5 (range: 0–4). Only one woman (0.2%) had a companion present (her husband). A partograph was used for the majority (84.8%), and 88.0% had no augmentation of labour with oxytocin. Few (6.2%) gave birth in a non-supine position, and few (12.4%) had early skin-to-skin contact with their newborn. ConclusionThere are several areas for improving childbirth care according to the Bologna score. Healthy newborns should be placed skin-to-skin with their mothers shortly after birth, non-supine birthing positions should be encouraged, and the importance of a companion during labour and birth should be considered.

Blood lactate level and meconium aspiration syndrome.

Approximately 5% of infants born with a meconium-stained amniotic fluid (MSAF) develop meconium aspiration syndrome (MAS). Early recognition of infants at highest risk for the development of MAS and the prediction of disease severity are important for optimizing the clinical strategies for prevention and treatment. The aim of the present study was to identify the risk factors for MAS and to investigate the effect of blood lactate level on the development of MAS. Between January 2011 and January 2012, data were recorded with regard to gender, mode of delivery, gestational week, birth weight, 5-min Apgar score, and need for resuscitation of the meconium-stained depressed infants who underwent tracheal aspiration. Moreover, the number of cases developing MAS, blood pH value, and lactate level in capillary blood gases obtained during the first hour after delivery, duration of oxygen supplementation, the number of cases receiving mechanical ventilation and surfactant therapy, duration of hospital stay, and outcomes of the infants were recorded. The number of live births during the study period was 17,202, and of them, 1,341 (7.8%) infants were born through MSAF. Of 195 infants who were meconium-stained depressed, 90 were girls and 105 were boys. Their mean gestational week was 39.37 ± 0.89 weeks and mean birth weight was 3,426 ± 634 g. Eighty-four of them were born through cesarean section (C/S), and 111 were born via normal spontaneous labor. For 40 infants, Apgar score at fifth minute was less than 6. In total, resuscitation was performed on 43 (22.9%) infants. Of the infants, 141 did not develop MAS and 54 developed MAS. While there were no significant differences between infants with and without MAS with regard to gender, delivery route, gestational week, and birth weight, a significant difference was observed regarding the Apgar score (p = 0.0001). The blood pH value in capillary blood gas analysis was less than 7.25 in 18 (28.5%) cases with MAS and four (3.2%) cases without MAS. There was no significant difference between infants with and without MAS with regard to blood pH levels (p = 0.031). The mean blood lactate level was 8.5± 3.4 mmol/L in the patients with MAS, and there was a significant difference between infants with and without MAS regarding blood lactate level (p = 0.0001). The mean duration of oxygen supplementation was 86.62 ± 66.52 and 44.36 ± 19.03 h in patients with MAS and without MAS, respectively. In total, 30 infants required mechanical ventilation (24 infants with MAS and 6 infants without MAS). In addition to mechanical ventilation, 16 infants with MAS were administered surfactant therapy. The mean duration of hospital stay of infants with MAS was significantly higher than infants without MAS (p = 0.0001). There was a correlation between blood lactate levels, blood pH value, and hospitalization duration (p < 0.05). All of the infants, except one patient, were discharged from the NICU. In addition to the blood pH value and 5-min Apgar score, increased blood lactate level may be a risk factor for the development of MAS in infants born with MSAF. This may aid in the early detection of MAS and, with appropriate measures taken sooner, reduce morbidity and mortality. Further studies are needed to elucidate the role of lactate level, which is an important indicator of hypoxia during the development of MAS.

Levels of cytokines in umbilical cord blood in relation to spontaneous term labor

Inflammatory mechanisms are thought to play an important role in the process of labor, both in preterm and spontaneous term delivery. We aimed to determine whether normal spontaneous vaginal delivery (SVD) at term was associated with an inflammatory activation compared with elective cesarean section (ECS) without previous onset of labor. Cytokine concentrations were measured in venous cord blood obtained from 60 term newborns (ECS, n=35; SVD, n=25) born to mothers with clinically uneventful pregnancy and without signs of infection. Both study groups showed no differences in birth weight, umbilical artery pH, Apgar at 5 min, and gender distribution. Infants delivered by ECS had lower gestational age: mean, 38.5 weeks (range, 37.0-39.6 weeks) vs. mean, 39.8 weeks (range, 37.9-42.4 weeks) (P<0.001). Concentrations of interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p40, IL-12p70, IL-17, IL-1 receptor antagonist, soluble IL-2 receptor α, granulocyte-macrophage colony-stimulating factor, interferon (IFN)-α2, IFN-γ, tumor necrosis factor (TNF)-α, TNF-β, and interferon inducible protein 10 were not different between ECS and SVD. Newborns after SVD displayed increased levels of transforming growth factor β1 (TGF-β1): mean, 8580 pg/mL (95% CI, 5554-11,606) vs. mean, 4864 pg/mL (95% CI, 2471-7257) (P<0.0012). Our findings suggest that, in healthy, term neonates, the exposition to normal spontaneous delivery and labor is not associated with systemic activation of different inflammatory mediators compared with ECS except for TGF-β1. Further studies are needed to evaluate the immunomodulatory role of labor-associated TGF-β1 increase in fetal cord blood.

Evidence for differential regulation of the adipokine visfatin in the maternal and fetal compartments in normal spontaneous labor at term

Visfatin, a novel adipokine with metabolic and immunoregulatory properties, has been implicated in the regulation of fetal growth, as well as in preterm labor. A gap in knowledge is whether spontaneous labor at term is associated with changes in the maternal and fetal concentrations of visfatin. The aim of this study was to determine if the presence of labor at term is associated with alterations in maternal and neonatal plasma visfatin concentrations. This cross-sectional study included 50 normal pregnant women at term and their appropriate-for-gestational age (AGA) neonates in the following groups: 1) 25 mother-neonate pairs delivered by elective cesarean section without spontaneous labor, and 2) 25 mother-neonate pairs who delivered vaginally following spontaneous labor. Maternal plasma and cord blood visfatin concentrations were determined by ELISA. Non-parametric statistics were used for analyses. 1) The median visfatin concentration was higher in umbilical cord plasma of neonates born following a spontaneous labor at term than that of those who were born by an elective cesarean section (P=0.02); 2) in contrast, the median maternal plasma visfatin concentration did not differ significantly between patients with and without labor (P=0.44); and 3) there was a significant correlation between umbilical cord plasma concentration of visfatin and both maternal visfatin concentration (r=0.54, P=0.005) and gestational age (GA) at delivery (r=0.58; P=0.002) only in the absence of labor. Term labor is associated with increased fetal, but not maternal, circulating visfatin concentrations. Previous reports indicate that preterm labor leading to preterm delivery is characterized by an increase in maternal plasma concentrations of visfatin. The observations reported herein support the view that there are fundamental differences in the endocrine and metabolic adaptations in normal labor at term and preterm labor.

227: Evidence for differential regulation of the adipokine visfatin in the maternal and fetal compartments in normal spontaneous labor at term

227: Evidence for differential regulation of the adipokine visfatin in the maternal and fetal compartments in normal spontaneous labor at term

The Arabin pessary for the treatment of threatened mid-trimester miscarriage or premature labour and miscarriage: a case series

Objective. The Arabin pessary may be beneficial in the treatment of cervical incompetence. The aim of the study was to analyse the efficacy of the treatment method of pregnant women with cervical incompetence.Methods. A non-randomised study performed in the obstetrical wards in Lodz, Poland utilising 54 pregnant women with cervical incompetence was developed to assess the efficiency of treatment methods of cervically incompetent women. These women were diagnosed by vaginal ultrasound examination during the course of the study. Patients with a cervical length of 15–30 mm before 28 weeks an Arabin cervical pessary were inserted, women whose cervical length was less than 15 mm were treated with cervical cerclage. The main end points of the study were preterm or term delivery.Results. In the Arabin pessary group, 1.9% of women delivered before the 29th week of gestation and 83.3% of women delivered after 37 weeks of pregnancy. Eighty-seven per cent of pregnant women treated for cervical incompetence by Arabin pessary delivered by normal spontaneous labour, 1.9% delivered by forceps labour and 11.1% of patients by caesarean section. Among pregnant women treated by Arabin pessary, 3.7% of newborns were estimated as having a score of 0–4 on the Apgar scale, 13% a score of 5–7 and 83.3% a score of 8–10.Conclusions. Cervical incompetence treatment effectively prolongs the duration of gestation. Application of the Arabin pessary is an effective method of cervical incompetence treatment.

Visfatin/Pre-B cell colony-enhancing factor in amniotic fluid in normal pregnancy, spontaneous labor at term, preterm labor and prelabor rupture of membranes: an association with subclinical intrauterine infection in preterm parturition

Visfatin, a novel adipokine originally discovered as a pre-B-cell colony enhancing factor, is expressed by amniotic epithelium, cytotrophoblast, and decidua and is over-expressed when fetal membranes are exposed to mechanical stress and/or pro-inflammatory stimuli. Visfatin expression by fetal membranes is dramatically up-regulated after normal spontaneous labor. The aims of this study were to determine if visfatin is detectable in amniotic fluid (AF) and whether its concentration changes with gestational age, spontaneous labor, preterm prelabor rupture of membranes (preterm PROM) and in the presence of microbial invasion of the amniotic cavity (MIAC). In this cross-sectional study, visfatin concentration in AF was determined in patients in the following groups: 1) mid-trimester (n=75); 2) term not in labor (n=27); 3) term in spontaneous labor (n=51); 4) patients with preterm labor with intact membranes (PTL) without MIAC who delivered at term (n=35); 5) patients with PTL without MIAC who delivered preterm (n=52); 6) patients with PTL with MIAC (n=25); 7) women with preterm PROM without MIAC (n=26); and 8) women with preterm PROM with MIAC (n=26). Non-parametric statistics were used for analysis. 1) The median AF concentration of visfatin was significantly higher in patients at term than in mid-trimester; 2) Among women with PTL who delivered preterm, the median visfatin concentration was significantly higher in patients with MIAC than those without MIAC; 3) Similarly, patients with PTL and MIAC had a higher median AF visfatin concentration than those with PTL who delivered at term; 4) Among women with preterm PROM, the median AF visfatin concentration was significantly higher in patients with MIAC than those without MIAC. 1) Visfatin is a physiologic constituent of AF; 2) The concentration of AF visfatin increases with advancing gestational age; 3) AF visfatin concentration is elevated in patients with MIAC, regardless of the membrane status, suggesting that visfatin participates in the host response against infection.

Anal sphincter lacerations and upright delivery postures—a risk analysis from a randomized controlled trial

To evaluate obstetric sphincter lacerations after a kneeling or sitting position at second stage of labor in a multivariate risk analysis model. Two hundred and seventy-one primiparous women with normal pregnancies and spontaneous labor were randomized, 138 to a kneeling position and 133 to a sitting position. Medical data were retrieved from delivery charts and partograms. Risk factors were tested in a multivariate logistic regression model in a stepwise manner. The trial was completed by 106 subjects in the kneeling group and 112 subjects in the sitting group. There were no significant differences with regard to duration of second stage of labor or pre-trial maternal characteristics between the two groups. Obstetrical sphincter tears did not differ significantly between the two groups but an intact perineum was more common in the kneeling group (p<0.03) and episiotomy (mediolateral) was more common in the sitting group (p<0.05). Three grade IV sphincter lacerations occurred in the sitting group compared to none in the kneeling group (NS). Multivariate risk analysis indicated that prolonged duration of second stage of labor and episiotomy were associated with an increased risk of third- or fourth-degree sphincter tears (p<0.01 and p<0.05, respectively). Delivery posture, maternal age, fetal weight, use of oxytocin, and use of epidural analgesia did not increase the risk of obstetrical anal sphincter lacerations in the two upright postures. Obstetrical anal sphincter lacerations did not differ significantly between a kneeling or sitting upright delivery posture. Episiotomy was more common after a sitting delivery posture, which may be associated with an increased risk of anal sphincter lacerations. Upright delivery postures may be encouraged in healthy women with normal, full-term pregnancy.

Expression of bone morphogenetic protein 2 in normal spontaneous labor at term, preterm labor, and preterm premature rupture of membranes

Genome-wide screening studies of the chorioamniotic membranes unexpectedly identified an increase in the expression of bone morphogenetic protein 2 in spontaneous labor at term. The objective of this study was to determine whether bone morphogenetic protein 2 messenger RNA and protein expression are altered in the chorioamniotic membranes of patients with term labor, preterm labor, and preterm premature rupture of membranes. Chorioamniotic membranes were obtained from patients at term (with and without labor), with preterm labor (with and without histologic chorioamnionitis), and with preterm premature rupture of membranes (with and without histologic chorioamnionitis). The expression of bone morphogenetic protein 2 was studied by real-time quantitative reverse transcriptase-polymerase chain reaction (n = 88) and immunohistochemistry (n = 124). Nonparametric statistics were used for analysis. Primary amnion cells obtained from women at term not in labor were treated with bone morphogenetic protein 2 to examine whether there was increased prostaglandin E2 expression. The median bone morphogenetic protein 2 messenger RNA and protein expression were significantly higher in the membranes of patients with spontaneous labor at term than in those of patients not in labor at term (P < .001 for both). Bone morphogenetic protein 2 messenger RNA and protein expression were increased in patients with preterm labor with histologic chorioamnionitis than in those without histologic chorioamnionitis (P < .05 and P < .001, respectively). There was no difference in bone morphogenetic protein 2 messenger RNA and protein expression in patients with preterm premature rupture of membranes, regardless of chorioamnionitis (P = .13 and P = .08, respectively). There was a correlation between bone morphogenetic protein 2 and cyclooxygenase 2 protein expression in chorioamniotic membranes (R = .34; P < .001). Bone morphogenetic protein 2 messenger RNA and protein expression are increased in the chorioamniotic membranes of patients with spontaneous labor at term and patients with preterm labor associated with histologic chorioamnionitis. Its expression pattern and biologic effects strongly suggest that bone morphogenetic protein 2 is involved in human parturition.

Evidence for the participation of bone morphogenetic protein-2 in normal spontaneous labor at term

Evidence for the participation of bone morphogenetic protein-2 in normal spontaneous labor at term

Pre-B-cell colony-enhancing factor, a novel cytokine of human fetal membranes

Objective: Our purpose was to determine whether pre-B-cell colony-enhancing factor (PBEF) is expressed in the human fetal membranes during normal gestation and parturition in the absence of infection and to show its effects on the expression of interleukin (IL)-6 and IL-8. Study Design: PBEF was immunolocalized in the fetal membranes from early pregnancy, at preterm, and at term. Its expression was quantitated by Northern analysis in separated uninfected amnion, chorion, decidua, and placenta of patients at term before labor and in full-thickness membranes before and after spontaneous labor at preterm and at term. Amnion-like epithelial (WISH) cells and fetal membrane explants were treated with recombinant PBEF (rhPBEF), and the expression of IL-6 and IL-8 was quantitated. Results: PBEF was immunolocalized throughout gestation in the amniotic epithelium and mesenchymal cells as well as the chorionic cytotrophoblast and parietal decidua. Northern analysis showed significantly more (P <.01) PBEF expressed in the amnion than in either chorion or placenta. Its expression increased after labor at both preterm and term and correlated with that of IL-8 (r = 0.87). rhPBEF treatment of WISH cells significantly increased IL-6 (P <.05) and IL-8 (P <.01) gene expression after 4 hours and of IL-8 protein after 24 hours (P <.01); similar 4-hour treatment of fetal membrane explants significantly increased IL-6 (P <.01) and IL-8 (P <.05) gene expression. Conclusion: PBEF is a novel cytokine constitutively expressed by the fetal membranes during pregnancy. It increased the expression of IL-6 and IL-8 and may be important in both normal spontaneous labor and infection-induced preterm labor. (Am J Obstet Gynecol 2002;187:1051-8.)

Effets de 0,4 mg de nitroglycérine sublinguale sur le relâchement utérin de parturientes à terme

Objectives: to measure the effect of 0.4mg of sublingual nitroglycerin spray on uterine activity in normal spontaneous or oxytocin-induced term labor and to evaluate the maternal and fetal side effects.Methods: at Centre Hospitalier Universitaire de Sherbrooke, 21 term pregnancies in labor, consented to have an intrauterine pressure catheter during the active phase (dilatation ≥ 4cm). The groups were: spontaneous labor (n = 6) receiving 0.4 mg sublingual nitroglycerin with dicontinuation of oxytocin perfusion during 30 minutes. A control group on oxytocin (n = 8) was studied where oxytocin perfusion was stopped during 30 minutes without receiving nitroglycerin. Maternal blood pressure and fetal heart rate were recorded 20 minutes before and over 60 minutes after the administration of nitroglycerin and/or the arrest of oxytocin perfusion. The frequency of uterine contractions. Montevideo units and the area under the curve of the contractions were calculated in 10 minutes windows before and after the administration of nitroglycerin and/or the arrest of oxytocin perfusion. P<0.05 was considered statistically significant.Results: the uterine activity during spontaneous labor showed a 20 percent reduction for the area under the curve after the administration of O.4mg nitroglycerin at 10-20 minutes (p = 0.06), without significant changes for the frequency of uterine contractions and Montevideo units. In stimulated or induced labor, the area under the curve decreased by 40 percent (p < 0.001) from 10 to 30 minutes after the administration of nitroglycerin and/or the arrest of the oxytocin perfusion, without any difference between the groups with or without nitroglycerin. No maternal or fetal side effects were observed.Conclusion: there was no clinically significant uterine relaxation in normal spontaneous labor with 0.4 mg of sublingual nitroglycerin spray. In stimulated or induced labor, the uterine activity was significantly decreased following the arrest of the oxytocin perfusion from 10 to 30 minutes without any additional relaxation with the concomitant use of nitroglycerin. At this concentration, there were no maternal or fetal side effects. For an obstetrical emergency in active labor at term, 0.4 mg nitroglycerin is ineffective to obtain a clinically significant uterine relaxation.

Prostaglandin E 2 production by endogenous secretion of interleukin-1 in decidual cells obtained before and after the labor

Previous reports revealed that interleukin-1(IL-1) was involved in the process of premature labor in the cases with intrauterine infection. However, the roles of the cytokine in normal spontaneous labor remain uncertain. The present studies aimed at determining the involvement of the cytokine in prostaglandin (PG)E 2 production during labor by the third trimester decidual cells. The cells were obtained at the time of normal spontaneous delivery (NVD) and elective cesarean section (ECS). The NVD cells produced significantly more amount of PGE2 than the ECS cells and the both cells responded to the addition of IL-1β to increase PGE 2 production. A specific inhibitor of cyclooxygenase-2 (COX-2), NS398, decreased basal PGE2 production and inhibited the stimulatory effect of IL-1f in a dose dependent manner in NVD cells. The NVD cells secreted more amount of IL-1 fl than the ECS cells and contained more amount of preprocessed 31kD IL-1 fl inside the cells. The addition of recombinant soluble human IL-1 receptor (type I) not only blocked the effect of IL-1β on PG secretion, but significantly reduced the basal production of PGE2 by NVD cells. These results indicate that decidual PG production depends upon COX-2 after the onset of labor. Besides it seems likely that endogenously produced IL-1β may be involved in autocrine fashion in inducing COX-2 after the onset of labor.

Myometrial steroid concentration and oxytocin receptor density in parturient women at term

The aim of this study was to measure oxytocin receptor concentration in myometrial tissue from term pregnant women with normal and dysfunctional labor and to relate this concentration to the progress of labor and to the levels of estradiol and progesterone in the same myometrium. Myometrial biopsies were obtained from 50 term pregnant women undergoing cesarean section. The patients were categorized as follows: not in labor, normal labor, successful oxytocin-augmented labor, and oxytocin-resistant labor. Specific binding of [ 3H]oxytocin to high-affinity sites in membrane preparations from myometrial tissues was determined. Estradiol and progesterone were assayed using tritiated steroids with a sensitive radioimmunoassay technique. Oxytocin receptor density was significantly lower in oxytocin-resistant labor compared to successful oxytocin-augmentated labor ( P < 0.04) and to spontaneously active normal labor ( P < 0.02). Oxytocin receptor concentration was also significantly lower in non-labor patients compared to normal spontaneous labor ( P < 0.01), and successful oxytocinaugmented labor ( P < 0.02). There was a positive relationship between the progress of cervical dilatation (cm/h) and oxytocin receptor density in the myometrium ( r = 0.408, P < 0.025). The concentration of progesterone and estradiol in the pregnant myometrium did not differ in patients with different types of labor or with the state of uterine contractile activity. Our results suggest that individual myometrial sensitivity is an important determinant of the response to administered oxytocin in humans. Furthermore, myometrial oxytocin receptor expression in vivo seems not be related to ovarian steroid concentration in the myometrium. The low oxytocin receptor density in oxytocin-resistant dystocia needs further investigation.

Control of peripartal collagenolysis in the human chorion-decidua

OBJECTIVE: This study was designed to observe the in vivo status of chorion-decidua gene expression for some major metalloproteinases, an inhibitor (tissue inhibitor of metalloproteinase-1), and an activator (tissue plasminogen activator) and the hormone relaxin at accessible time points in the peripartial period. STUDY DESIGN: Chorion-decidua from patients at cesarean section with and without labor and after spontaneous labor and delivery was used for preparation of poly (A) + ribonucleic acid and quantitative Northern analyses with a series of oligo and complementary deoxyribonucleic acid probes. RESULTS: In the period designated as the period before parturition, relaxin and matrix metalloproteinase-1 (interstitial collagenase) gene expression were relatively high, reflecting the controlled loss of amniotic collagen necessary for fetal membrane expansion without rupture as the uterine volume increases. When active labor has begun, but before delivery, matrix metalloproteinase-3 (stromelysin) and matrix metalloproteinase-9 (type V collagenase) gene levels significantly increased. After normal spontaneous labor and delivery, tissue plasminogen activator and tissue inhibitor of metalloproteinase-1 messenger ribonucleic acids significantly increased, together with a marginally increased expression of the genes for matrix metalloproteinase-1, matrix metalloproteinase-2 (type IV collagenase), and relaxin. CONCLUSION: The expression of the genes for some major collagenolytic enzymes, an inhibitor, activator, and relaxin in the chorion-decidua, is different at the different stages of parturition.

Prostaglandin production during spontaneous labor and after treatment with RU486 in pregnant rhesus macaques.

The production of prostaglandins from amnion, chorion, decidua, and myometrium was studied in a superfusion system to determine the level of prostaglandin production during late pregnancy, during spontaneous labor, and after in vivo treatment with RU486. Tissues were divided into three groups: those from pregnant control animals, those from animals receiving RU486 (20 mg/kg/day for 3 days) in vivo, and those from animals in spontaneous term labor. Tissues were collected at cesarean section and placed in the superfusion system. After a 30-min equilibration period, fractions of media were collected after passing through the tissue chambers and were assayed for prostaglandin F2 alpha (PGF2 alpha) and prostaglandin E2 (PGE2). The results showed a significant increase in PGF2 alpha from decidua of animals treated with RU486 compared to pregnant controls (pregnant: 3.01 +/- 0.45 ng/g/min; RU486: 4.45 +/- 0.28 ng/g/min; p < 0.05). There was a dramatic increase in PGE2 production by amnion from animals in spontaneous labor but not after RU486 treatment (pregnant: 0.21 +/- 0.06 ng/g/min; RU486: 0.56 +/- 0.09 ng/g/min; spontaneous labor: 5.83 +/- 0.43 ng/g/min; p < 0.01). We conclude that while progesterone is important for maintaining uterine quiescence during pregnancy, progesterone receptor blockade by RU486 does not lead to an increase in PGE2 production by amnion as is shown during normal spontaneous labor.

Pharmacological Management of Labor

Normal spontaneous labor at term without maternal or fetal complications does not always occur. In these situations, pharmacological intervention is often the safest and most suitable method of delivery. The pharmacological management of labor includes the use of multiple agents that alter cervical dilatation and uterine contractions, resulting in delivery of the fetus and treatment of postpartum emergencies. This article provides a description of normal and abnormal labor patterns and possible peripartum complications. The use of oxytocin, ergot derivatives, and prostaglandins for augmentation of dysfunctional labor, induction of labor, and management of peripartum emergencies is discussed to provide information on availability of product, indications for use, clinical efficacy, potential adverse effects, and contraindications to use.

Maternal Temperature Regulation During Extradural Analgesia for Labour

We have studied the effect of analgesia on maternal temperature (oral and tympanic membrane) progression in 53 women during normal spontaneous labour. Three groups were studied: two received extradural analgesia with a continuous infusion of 0.25% bupivacaine with or without the addition of fentanyl; the third group received only parenteral opioid analgesia. All patients were afebrile and without clinical evidence of infection at the beginning of the study. Both groups of patients receiving extradural analgesia had a consistent and significant increase in temperature after approximately 5 h of analgesia; no such trend was observed in the parenteral opioid group. Alterations in mechanisms of heat dissipation may explain these findings.

MATERNAL TEMPERATURE REGULATION DURING EXTRADURAL ANALGESIA FOR LABOUR

We have studied the effect of analgesia on maternal temperature (oral and tympanic membrane) progression in 53 women during normal spontaneous labour. Three groups were studied: two received extradural analgesia with a continuous infusion of 0.25% bupivacaine with or without the addition of fentanyl; the third group received only parenteral opioid analgesia. All patients were afebrile and without clinical evidence of infection at the beginning of the study. Both groups of patients receiving extradural analgesia had a consistent and significant increase in temperature after approximately 5 h of analgesia; no such trend was observed in the parenteral opioid group. Alterations in mechanisms of heat dissipation may explain these findings.