Total complement activity in maternal sera, amniotic fluids and cord sera in women with premature labor, premature rupture of membranes or chorioamnionitis

Total hemolytic complement activity (CH50) was determined in maternal sera, amniotic fluids or cord sera, or all, from 119 patients with preterm uterine contractions, premature rupture of membranes or chorioamnionitis, or all, at 24 to 40 weeks of gestation. The mean CH50 of maternal sera exceeded the mean CH50 of both amniotic fluids and cord sera. The mean CH50 of amniotic fluids exceeded that of cord sera and increased significantly at 32 weeks. This rise preceded that of the mean CH50 of cord sera, which occurred at a fetal weight of approximately 2,500 grams. The mean CH50 of amniotic fluids varied significantly and inversely with that of cord sera. The levels of CH50 in these three fluids did not distinguish between patients with preterm uterine contractions who delivered prematurely and those who delivered at term. The CH50 in patients with premature rupture of membranes did not differ from a control population of women with uncomplicated pregnancies. The mean CH50 of maternal sera was increased in patients with chorioamnionitis but was not predictive of chorioamnionitis. The mean CH50 of maternal sera was decreased in patients who smoked cigarettes and in patients who received intravenous ritodrine.     

Clinical chorioamnionitis is not predicted by an ultrasonic biophysical profile in patients with premature rupture of membranes

A modified biophysical profile was assessed serially in 47 patients with premature rupture of membranes who were not in labor. This profile included fetal movement, fetal tone, fetal breathing, amniotic fluid volume, and placental grade. The most recent study, obtained within 2 days of delivery, was compared with pregnancy outcome as reflected by the development of chorioamnionitis and/or neonatal sepsis. No study patient received antibiotics, steroids, or tocolytics before labor. Neither the composite biophysical profile nor any of its components were found to be different between patients with and without clinical chorioamnionitis. Neonatal sepsis was not observed. These data do not support the use of the biophysical profile as a predictor of maternal infection.     

The significance of C-reactive protein levels in women with premature rupture of membranes

In a prospective study of 100 patients with preterm premature rupture of membranes, clinical chorioamnionitis was present in 18 and histologic chorioamnionitis was present in 63. Patients who were managed conservatively for premature rupture of membranes were monitored by C-reactive protein determination, white blood cell and differential counts, maternal temperature, and fetal heart tone. C-reactive protein was measured nephelometrically (Immuno-chemistry Analyzer II, Beckman). Elevated C-reactive protein levels correlated well with both the pathologic and the clinical diagnosis of chorioamnionitis. Elevated C-reactive protein levels (at least 12 to 24 hours before delivery) were more sensitive than other standard laboratory or clinical tests in predicting chorioamnionitis both by clinical and pathologic criteria. When C-reactive protein values were normal, clinical chorioamnionitis was rarely found, whereas pathologically diagnosed chorioamnionitis was found half of the time. We conclude that although the C-reactive protein level is a very sensitive predictor of infectious morbidity in premature rupture of membranes, its specificity is not high.     

Histologic chorioamnionitis and preterm delivery in different patient populations

The placentas of 1843 deliveries were examined for the presence of histologic chorioamnionitis, which was classified as mild, moderate, or severe. Chorioamnionitis was present in 7.5% of patients who underwent cesarean before labor and in 18 and 32% of those delivering at term and preterm, respectively. Chorioamnionitis was severe in 74% of preterm but in only 15% of term deliveries. Premature rupture of membranes (PROM) was more frequent with preterm than with term delivery, with chorioamnionitis present in 42 and 15% of patients, respectively. Although chorioamnionitis was equally frequent in women with intact membranes delivering preterm and term, chorioamnionitis was severe in 63% of preterm and 14% of term deliveries (P less than .001). The frequency and severity of chorioamnionitis were related inversely to gestational age at preterm birth. Preterm delivery was more frequent in black than in white patients (19 versus 9%) and in indigent clinic versus private patients (13 versus 7.5%). However, there was no significant difference in frequency and severity of chorioamnionitis between black and white or between indigent clinic and private patients who delivered preterm. Among term births, chorioamnionitis was more often severe in black than in white patients. Chorioamnionitis in term deliveries was more frequent in clinic than in private patients; however, this was not true when only severe chorioamnionitis was considered. There were no differences in PROM between these patient populations. Thus, higher preterm birth rates in black and indigent clinic populations are not due to the more frequent occurrence of chorioamnionitis.     

Evaluation of the weekly cervical examination in a preterm birth prevention program

The efficacy of regular cervical examinations in detecting preterm labor, as well as possible risks, was studied for 133 preterm labor patients who had received regular cervical examinations as part of a preterm birth prevention program. When compared to all other patients experiencing preterm labor during the study period, the rates of preterm premature rupture of the membranes, chorioamnionitis, and postpartum endomyometritis were not increased. For 95 patients with preterm labor within 7 days of a routine cervical examination, labor onset was not temporally associated with the preceding examination. Preterm labor was diagnosed in 18 asymptomatic patients (18.2%) when the weekly examination revealed cervical change. Routine cervical exams, therefore, did not increase morbidity, and for some patients identified preterm labor before symptoms appeared.     

Is there an association between water baths during labor and the development of chorioamnionitis or endometritis?

OBJECTIVE: Our purpose was to determine whether water baths during labor are associated with the development of chorioamnionitis or endometritis. STUDY DESIGN: One hundred ten cases of chorioamnionitis or endometritis and 97 controls were identified among singleton term gestations from the University of California at San Francisco perinatal database. Medical record review and patient interviews provided information on membrane rupture, history of bathing during labor, and relaxation and pain relief perceived by patients who experienced water bathing during labor. RESULTS: There was no statistically significant association between water baths during labor and the occurrence of chorioamnionitis or endometritis (odds ratio 0.93 [95% confidence interval 0.53 to 1.63]). CONCLUSIONS: Water baths during labor are not associated with chorioamnionitis or endometritis. (Am J Obstet Gynecol 1998;178:1215-21.)     

Recurrence of clinical chorioamnionitis in subsequent pregnancies

OBJECTIVE: To establish the role of clinical chorioamnionitis as an independent risk factor for recurrence in a subsequent pregnancy. METHOD: This was a historical cohort study of pregnant women who had their first and second deliveries at our institution between January 1988 and May 2005. The index pregnancy was restricted to those who delivered vaginally. Data were collected from a continuously updated obstetric database and included demographic and labor characteristics and neonatal outcomes. Chorioamnionitis was diagnosed clinically. RESULTS: The study population consisted of 23,397 women. During the index pregnancy, 10% of women developed chorioamnionitis. This group was significantly different from the rest of the cohort in terms of age, ethnicity, length of labor, epidural analgesia, use of internal monitors, and incidence of prolonged rupture of membranes. In the second pregnancy, 6% of those women again developed chorioamnionitis compared with 2% of women who did not have chorioamnionitis in the first pregnancy (odds ratio 2.93, 95% confidence interval 2.40-3.57). After adjusting for the above confounders, the increased risk of recurrence persisted (odds ratio 1.85, 95% confidence interval 1.49-2.30). CONCLUSION: Women delivering vaginally who were diagnosed with chorioamnionitis during their first pregnancy are at increased risk for chorioamnionitis in a subsequent pregnancy. This supports the concept that there may be a predisposition to chorioamnionitis that should be further investigated. LEVEL OF EVIDENCE: II-2.     

C-reactive protein with premature rupture of membranes and premature labor

C-reactive protein (CRP) was determined serially in 31 patients with premature rupture of the membranes, 41 patients in premature labor, and 18 pregnant patients with a variety of high-risk conditions. Elevated levels of CRP were not predictive of clinical amnionitis, histologic chorioamnionitis, or neonatal sepsis. No discernible relationship was found between serum CRP and peripheral white blood cell count. CRP was not elevated (false negative) in two patients in the premature labor group with culture-proved bacterial amnionitis. Elevated CRP in the absence of infection (false positive) likewise occurred. The results suggest that CRP be used in conjunction with other signs and symptoms suggestive of chorioamnionitis, rather than as a pathognomonic test.     

Clinical chorioamnionitis is not predicted by umbilical artery Doppler velocimetry in patients with premature rupture of membranes.

Chorioamnionitis substantially increases fetal and neonatal morbidity. Infants born to women with chorioamnionitis have a fourfold increase in neonatal morbidity. If this condition could be predicted before the clinical manifestation and thereby treated earlier, an improved perinatal outcome might reasonably be expected. Based on the in vitro model of bacteria-induced vasoconstriction and pulmonary hypertension noted in sheep and lambs after exposure to the spent medium of a bacterial culture, we theorized that infected amniotic fluid may produce vasospasm of umbilical and placental vessels, reduce fetal perfusion, and increase perinatal asphyxia, morbidity, and mortality. Umbilical vessel vasospasm may be detected by measuring the systolic-diastolic ratio (S/D) of the umbilical artery. Continuous Doppler flow studies of the umbilical artery S/D were performed prospectively on 51 patients with premature rupture of membranes who were not in labor. The most recent test, done within 1 day of delivery, was compared with pregnancy outcome. Ten subjects developed clinical chorioamnionitis, of whom none had an abnormal S/D. Six of 41 women without clinical chorioamnionitis had abnormal S/Ds. These data do not support the use of Doppler measurement of the S/D as a predictor of clinical chorioamnionitis.     

Management of term patients with premature rupture of membranes and an unfavorable cervix.

The purpose of this prospective investigation was to evaluate a protocol for management of term patients with premature rupture of membranes (PROM) and a cervix unfavorable for induction of labor (Bishop score 4 or less). Patients initially were observed for 24 to 36 hours for the spontaneous onset of labor. If spontaneous contractions did not commence, labor was induced with oxytocin. Patients subsequently were divided into three groups: 44 who had spontaneous labor, 29 who had spontaneous labor but required oxytocin augmentation, and 39 women who had oxytocin induction. Patients who entered labor spontaneously had a significantly shorter mean latent period between rupture of membranes and onset of labor (16.0 versus 26.8 and 40.7 hours), shorter mean duration of labor (7.6 versus 12.1 and 13.1 hours), and shorter mean duration of rupture of membranes (23.6 versus 39.0 and 53.8 hours). These women also had a significant decrease in the frequency of chorioamnionitis (7 versus 14 and 33%), and their infants had fewer evaluations for sepsis (25.0 versus 34.5 and 53.8%). We conclude that term patients with PROM and an unfavorable cervix who require oxytocin augmentation or induction of labor are at increased risk for intrapartum and neonatal infection compared with those who progress through labor spontaneously.     

Study of interleukin-6 and tumor necrosis factor-alpha levels in maternal serum and amniotic fluid of patients with premature rupture of membranes

To study the change and clinical significance of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) levels in the maternal serum and amniotic fluid of pregnant women with chorioamnionitis and with premature rupture of membranes. Twenty-six normal-term pregnant women formed the control group, and forty-six pregnant women with premature rupture of membranes were enrolled for the study. Maternal serum and amniotic fluid IL-6 and TNF-alpha levels were measured using a sensitive radioimmunoassay and enzyme-linked immunosorbent assay (ELISA); chorioamnionitis was diagnosed by fetal membrane pathology. The maternal serum IL-6 levels and amniotic fluid IL-6 and TNF-alpha levels were higher than those of the control (P < 0.01). There was a significant relationship between maternal serum IL-6 and maternal serum and amniotic fluid IL-6 and TNF-alpha with the time of the premature rupture of membranes, i.e. the longer the time, the higher the maternal serum and amniotic fluid IL-6 and TNF-alpha. There were 12 patients with chorioamnionitis in premature rupture of membranes and their maternal serum and amniotic fluid IL-6 and TNF-alpha levels were higher than that of non-chorioamnionitis patients (P < 0.01-0.05). IL-6 and TNF-alpha levels in maternal and amniotic fluids are a valuable index in identification of the chorioamnionitis in patients with premature rupture of membranes.     

Prenatal diagnosis of Candida albicans chorioamnionitis

The use of diagnostic amniocentesis has been proposed for the evaluation of patients with clinical suspicion of chorioamnionitis, such as those with premature rupture of membranes and premature labor. We describe a patient in whom the diagnosis of Candida chorioamnionitis was made after diagnostic amniocentesis with the assistance of a simple and rapidly performed potassium hydroxide smear.     

Premature rupture of membranes: the role of C-reactive protein in the prediction of chorioamnionitis

A group of 52 patients with premature rupture of the membranes (PROM) before 34 weeks' gestation were evaluated prospectively and managed expectantly. Of 42 patients who were delivered of their infants, 26 (61.9%) had significant chorioamnionitis on histopathology, and 18 had positive microbial cultures at delivery. However, only seven patients (16.7%) developed clinical signs of chorioamnionitis. There were no maternal deaths or perinatal deaths attributable to sepsis. Only two infants (less than 5%) had positive blood cultures. All patients were assessed daily for the development of chorioamnionitis. Amniocenteses were not routinely performed. White blood cell counts, band neutrophil counts, and erythrocyte sedimentation rate determinations were found to be unreliable. C-reactive protein determinations were found most reliable with a high sensitivity and specificity. Elevated C-reactive protein levels correlated better with pathologic confirmation of chorioamnionitis than with the clinical febrile morbidity. Clinical implications for the management of PROM are discussed.     

Management of premature rupture of membranes at term.

Although prelabor rupture of membranes at term is common, in most cases, the spontaneous onset of labor relieves the obstetrician of the need for making management decisions. The standard practice in the United States has been to induce labor with intravenous oxytocin in that minority of patients who fail to labor spontaneously. Controlled trials suggest that this practice is associated with higher rates of both chorioamnionitis and the need for cesarean delivery than is expectancy. Expectancy, however, has not been demonstrated to be safer for the perinate.     

Chorioamnionitis and the prognosis for term infants.

OBJECTIVE: To assess the effects of clinical chorioamnionitis and labor complications on short-term neonatal morbidity, including seizures. METHODS: This was a retrospective cohort study of all live-born term infants who weighed more than 2500 g delivered between 1988 and 1997 at Parkland Memorial Hospital, Dallas, Texas. Infant outcomes were compared between women with and without clinical diagnoses of chorioamnionitis. Chorioamnionitis was based on maternal fever of 38C or greater with supporting clinical evidence including fetal tachycardia, uterine tenderness, and malodorous infant. RESULTS: A total of 101,170 term infants were analyzed, 5144 (5%) of whom were born to women with chorioamnionitis. Apgar scores of 3 or less at 5 minutes, umbilical artery pH of 7.0 or less, delivery-room intubation, sepsis, pneumonia, seizures in the first 24 hours, and meconium aspiration syndrome were all increased in infants exposed to chorioamnionitis. After adjustment for confounding factors, including route of delivery and length of labor, chorioamnionitis remained significantly associated with intubation in the delivery room (odds ratio [OR] 2.0; 95% confidence interval [CI] 1.5, 2.6), pneumonia (OR 2.2; 95% CI 1.7, 2.8), and sepsis (OR 2.9; 95% CI 2.1, 4.1). Short-term neurologic morbidity, manifest as seizures, was not related to maternal infection during labor, but was significantly related to other labor complications. CONCLUSION: The main short-term neonatal consequence of chorioamnionitis is infection. Short-term neurologic morbidity in infants is related to labor complications and not chorioamnionitis per se.     

Increased rates of chorioamnionitis with extra-amniotic saline infusion method of labor induction

OBJECTIVE: Extra-amniotic saline infusion has been shown to be equal to or more efficacious than misoprostol, laminaria, dinoprostone, and prostaglandin estradiol for cervical ripening and labor induction. Because of the introduction of a foreign body into the uterus, extra-amniotic saline infusion may potentially cause increased rates of chorioamnionitis. This study examines the risk of chorioamnionitis with extra-amniotic saline infusion compared with other methods of induction and spontaneous labor. METHODS: A retrospective analysis was performed based on deliveries at Bellevue Hospital Center, a tertiary-care facility, from August 2000 to December 2002. Three groups were identified: extra-amniotic saline infusion, other methods of induction, and spontaneous labor. Differences in chorioamnionitis rates were analyzed by using analysis of variance and multivariable logistic regression as appropriate. RESULTS: There were 625 charts evaluated: 171 extra-amniotic saline infusion, 190 other, and 264 with spontaneous labor. The rates of chorioamnionitis were 26.9%, 17.9%, and 13.3%, respectively. After adjusting for confounding variables, such as instrumentation, length of rupture, and number of exams, subjects who were induced with extra-amniotic saline infusion were significantly more likely to develop chorioamnionitis (relative risk = 2.2; 95% confidence interval 1.4, 4.0; P =.006). CONCLUSION: Extra-amniotic saline infusion may be associated with a greater risk of chorioamnionitis when compared with other methods of labor induction. Given the increased risk of chorioamnionitis associated with extra-amniotic saline infusion, its use should be in the context of a careful assessment of the risks and benefits of various methods of labor induction. LEVEL OF EVIDENCE: II-2     

Ampicillin prophylaxis in preterm premature rupture of the membranes: a prospective randomized study

It is hypothesized that ampicillin may treat subclinical deciduitis and prolong the "effective" latent period in patients with preterm premature rupture of the membranes. We studied 82 patients with preterm rupture of membranes who were managed expectantly and were randomly assigned either to receive ampicillin prophylaxis (n = 43) or not to receive ampicillin prophylaxis (n = 39). Patients were excluded from study entry on admission if they had suspected or frank chorioamnionitis, active preterm labor, a history of penicillin allergy, multiple gestation, or cervical cerclage. There were no significant differences between the groups in duration of membrane rupture prior to admission, gestational age at membrane rupture, use of steroids and tocolysis, and demographic factors. Life-table analysis showed that the risk of delivery was significantly lower for the group of patients receiving prophylactic ampicillin. The incidence of neonatal infection was significantly lower in the ampicillin group, 1 (2%) versus 6 (17%), p less than 0.04.