William N. P. Herbert

Amniotic fluid interleukin-10 concentrations increase through pregnancy and are elevated in patients with preterm labor associated with intrauterine infection

OBJECTIVE To better understand the role of the antiinflammatory cytokine interleukin-10 in preterm labor and infection, we evaluated the amniotic fluid interleukin-10 concentrations through pregnancy, in term, and in preterm labor. STUDY DESIGN Amniotic fluid interleukin-10 levels were measured in 147 women throughout pregnancy including patients in the second trimester, patients at term with and without labor, and in patients in preterm labor with and without an intrauterine infection. We compared the amniotic fluid interleukin-10 concentrations among these five groups using the Mann-Whitney U test. RESULTS Amniotic fluid interleukin-10 was detected in 70% to 91% of patients in each of the five study groups. Higher concentrations were found at term compared with the second trimester (p < 0.001) and concentrations were significantly greater in patients with preterm labor and intrauterine infection compared with those patients in preterm labor without infection (p < 0.001), patients at term in labor (p < 0.001), or patients at term not in labor (p < 0.001). When the patients in preterm labor with infection were analyzed by gestational age, those patients at < 30 weeks had significantly higher amniotic fluid concentrations of interleukin-10 (p = 0.014). CONCLUSIONS Interleukin-10 was present in the amniotic fluid of the majority of pregnancies, with higher concentrations found at term compared with the second trimester. Intrauterine infection was associated with significantly increased concentrations, with even higher concentrations found in the very premature pregnancies. Interleukin-10 has a prominent yet undefined role in pregnancy and preterm labor complicated by intrauterine infection.

Maternal serum interleukin-6 during pregnancy and during term and preterm labor

Objective To determine the normal concentrations of maternal serum interleukin-6 during the second and third trimesters of pregnancy and the different stages of term and preterm labor, and to examine the clinical usefulness of measuring this cytokine in the serum of women in preterm labor to diagnose asymptomatic intrauterine infections. Methods Maternal serum interleukin-6 concentrations were measured cross-sectionally in 315 gravidas in their second and third trimesters and during term and preterm labor. Placentas from women who delivered preterm were examined for histologic chorioamnionitis. Results At term, women in labor had significantly elevated median maternal serum interleukin-6 concentrations compared with those at term not in labor (4.7 pg/mL versus 2.2 pg/mL, P < .001). Women admitted in preterm labor who delivered had significantly higher median interleukin-6 concentrations than did those in preterm labor who responded to tocolysis (9.3 pg/mL versus 1.9 pg/mL, P < .001). Women in preterm labor who delivered preterm with evidence of chorioamnionitis had significantly higher serum concentrations of interleukin-6 than did those in preterm labor who delivered in the absence of chorioamnionitis (15.9 pg/mL versus 4.6 pg/mL, P = .006). Conclusion Compared with antepartum gravidas, those in term or preterm labor had significantly higher concentrations of maternal serum interleukin-6 concentrations; extremely elevated levels were found in patients whose preterm labor was associated with intrauterine infection.

Maternal serum cytokines in preterm premature rupture of membranes.

OBJECTIVE: To estimate whether maternal serum interleukin (IL)-6 or granulocyte colony-stimulating factor (G-CSF) obtained daily are elevated in women with preterm premature rupture of membranes who develop funisitis. METHODS: Daily blood samples were obtained from women with preterm premature rupture of membranes and analyzed for IL-6 and G-CSF by enzyme-linked immunosorbent assay. Funisitis was determined by placental examination. Observations were stratified based on the presence or absence of funisitis and analyzed. Proportional hazards models were used to evaluate time-to-delivery on the basis of diagnostic IL-6 and G-CSF levels, determined by receiver operating characteristic curve analysis. RESULTS: Of the 107 patients available for analysis, 54 (50%) had evidence of funisitis after delivery. Patients with funisitis were more likely to deliver at an earlier gestational age (28.5 weeks compared with 31.5 weeks, P<.001) and have Medicaid insurance (57% compared with 39%, P=.04). Serum IL-6 and G-CSF were elevated 24 to 48 hours before delivery in women with preterm premature rupture of membranes with funisitis compared with those without funisitis (IL-6, 7.5 compared with 2.8 pg/mL, P<.001; G-CSF, 121.7 compared with 56.9 pg/mL, P=.002). Using values identified by the receiver operating characteristic curve, elevated serum IL-6 in the interval 24–72 hours before delivery was significantly associated with funisitis (P<.03), even after controlling for gestational age and insurance status. CONCLUSION: Maternal serum IL-6 and G-CSF appear to be biomarkers in the identification of women with preterm premature rupture of membranes likely to develop funisitis. LEVEL OF EVIDENCE: II

Cardiac troponin T levels in umbilical cord blood.

OBJECTIVE We sought to determine cardiac troponin T concentrations in umbilical cord plasma from normal and complicated pregnancies. STUDY DESIGN At the time of delivery, umbilical cord arterial and venous samples were collected from 209 neonates, and cardiac troponin T levels were measured by immunoassay. Comparisons of clinical factors were made between neonates with normal and elevated cardiac troponin T levels. Significance was deemed present at P <.05. RESULTS Twelve neonates had elevated cardiac troponin T levels. Exposure to magnesium sulfate was associated with an elevated cardiac troponin T level (relative risk, 33.2; 95% confidence interval, 7.7-143). CONCLUSIONS Cardiac troponin T levels were elevated in neonates exposed to magnesium sulfate in utero. The explanation of this finding and its clinical significance are unknown. Characterization of fetal and neonatal troponin T requires further study.

Apoptosis in the chorion laeve of term patients with histologic chorioamnionitis.

OBJECTIVE: The balance between cell survival and cell death (apoptosis) is critical during development and may affect organ function. Apoptosis is accelerated in the presence of infection and inflammation in a variety of organ systems. The objective of this investigation was to determine if apoptosis was increased in the chorion laeve of term patients with and without histologic chorioamnionitis. METHODS: Records of placental pathology were reviewed with respect to the presence/absence of histologic chorioamnionitis. Sections from formalin-fixed, paraffin-embedded fetal membrane rolls were stained using the TUNEL method. The proportion of apoptotic nuclei was calculated in seven high-powered fields/section. Those with and without histologic chorioamnionitis were compared. Data were analyzed using the Mann-Whitney U test, with significance defined as p < 0.05. RESULTS: There was no significant difference in demographic or clinical characteristics between the two groups. The chorion laeve from subjects with histologic chorioamnionitis had significantly more apoptotic nuclei when compared to those without chorioamnionitis (11.2% vs. 5%, p = 0.02). CONCLUSION: Apoptosis is more prevalent in the chorion laeve of fetal membranes with histologic chorioamnionitis. This finding suggests that infection/inflammation may impact cell survival within fetal membranes. The implications of these findings warrant further investigation.

Repeated fetal betamethasone treatment and birth weight and head circumference

Objective To assess the effect of repeated courses of betamethasone on birth weight and head circumference. Methods We conducted a historical cohort study of inpatients receiving betamethasone therapy over 5 years. We compared birth weights and head circumferences of infants whose mothers received one course of betamethasone with those of infants whose mothers received multiple courses. Multiple regression analysis was used to adjust for potential confounding variables. Sufficient power (80%) existed to detect a 20% difference between the groups (&agr; = 0.05). Results Mean birth weights (±SD) were 1717 ± 707 g in the single-course group (n = 107) and 1783 ± 647 g in the multiple-course group (n = 45) (P = .59, Student t-test). Mean head circumference was 28.2 ± 3.6 cm in the single-course group and 29.2 ± 2.9 cm in the multiple-course group (P = .15, Student t-test). In regression analysis, birth weights (1757 g and 1752 g) and head circumferences (28.5 cm and 29.0 cm) did not differ significantly different between the single-course and multiple-course groups. Conclusion Multiple courses of betamethasone do not reduce birth weight or head circumference in neonates compared with single-course therapy.

Pseudotumor cerebri in pregnancy.

Pseudotumor cerebri is an enigmatic neurologic disorder markedly more common in women of childbearing age. Diagnosis, management, and pregnancy outcome of nine women with active disease are described. Pregnancy is not contraindicated in women with pseudotumor cerebri, and termination of pregnancy is seldom required.

Use of the TDx-FLM assay in evaluating fetal lung maturity in an insulin-dependent diabetic population

Objective To assess the usefulness of the recently introduced TDx-FLM assay in managing pregnant women with diabetes. Methods Participating institutions were recruited from the 1993 and 1994 Society of Perinatal Obstetricians Diabetes Special Interest Group meetings. Study patients consisted of insulin-dependent diabetic women who had undergone transabdominal amniocentesis with assay of the fluid by the TDx-FLM method. Pertinent data were requested concerning pregnancy and respiratory outcomes of the corresponding neonates. Results Data from 261 pregnancies at 13 institutions were collected. Eight of the 182 infants born within 4 days of amniocentesis developed respiratory distress syndrome (RDS); five of the eight infants with RDS required intubation, and all five had TDx-FLM values less than 70 mg of surfactant per gram of albumin. Three of the eight infants with RDS required hood oxygen only; two of these infants had TDx-FLM values at least 70 mg/g. Thirteen of 144 (9%) subjects who delivered within 4 days of amniocentesis and for whom a TDx-FLM assay and phosphatidylglycerol level were both reported had a TDx-FLM level of at least 70 mg/g and a negative phosphatidyiglycerol result. No infant with this combination of results developed RDS. Fifteen of the 40 patients who delivered more than 4 days after amniocentesis, with both tests available, had TDx-FLM values at least 70 mg/g and were phosphatidylglycerol negative. Conclusion In infants of diabetic mothers, TDx-FLM values at least 70 mg/g were not associated with RDS requiring intubation. The TDx-FLM assay may be useful in determining the best time of delivery for pregnant patients with diabetes, especially in a situation in which the TDx-FLM assay is mature and the phosphatidylglycerol result is immature.

Placental Pathology in Patients Using Cocaine: An Observational Study

Objective Although retroplacental hemorrhage is a major cause of fetal death, its etiology often remains obscure. In some reports, cocaine use by pregnant women has been associated with retroplacental hemorrhage and clinical abruptio placentae. This study was designed to assess the occurrence of chorionic villus hemorrhage, an entity shown recently to be associated with retroplacental hemorrhage, in the placentas of cocaine users. Methods Twenty-nine placentas from cocaine users and 15 placentas from drug-free controls, as determined by questionnaire and urine toxicology screen, were examined prospectively, and pathological findings documented. The prevalence of retroplacental hemorrhage, chorionic villus hemorrhage, edema, chorioamnionitis, funisitis, infarction, fetal vessel thrombosis, and intervillus hemorrhage was examined in the two groups. Results Chorioamnionitis was the most frequent finding in both groups (58% of cocaine users, 66% of controls). Edema of moderate severity or greater was found only in the cocaine-using group (17%). The prevalence of chorionic villus hemorrhage among women using cocaine also was 17%. Conclusion Cocaine use during pregnancy may be associated with chorionic villus hemorrhage and villus edema, even in the absence of clinical abruptio placentae. The relationship between abnormal placental morphology and adverse perinatal outcomes remains to be determined.

Maternal serum granulocyte-colony stimulating factor in preterm birth with subclinical chorioamnionitis

Preterm birth has been linked with intrauterine infection and inflammation. Serum and amniotic fluid markers of inflammation, such as interleukin-1 (IL-1), IL-6, and granulocyte-colony stimulating factor (G-CSF), have been associated with clinical chorioamnionitis and preterm delivery. As G-CSF regulates the production and maturation of neutrophils, we sought to determine if maternal serum G-CSF levels are elevated in patients with preterm birth with subclinical histologic chorioamnionitis. Maternal serum G-CSF levels were significantly different among five groups of women studied (P < .001, Kruskall-Wallis test), and were highest in subjects with preterm labor who delivered preterm (P < .05, Mann-Whitney U test). Among women with preterm labor who delivered preterm, maternal serum G-CSF levels were significantly higher if histologic chorioamnionitis was present than when histologic evidence of infection was not present (P = 0.04, Mann-Whitney U test). Intrauterine infection may cause a local inflammatory process and initiate preterm labor. This inflammatory response may include production of G-CSF, which would enter the circulation and stimulate the migration of neutrophils to the site of infection. Our data support this concept, as maternal serum G-CSF is elevated with subclinical infection in association with preterm birth.