Significance of surgical first assistant expertise for surgical site infection prevention: Propensity score matching analysis

Surgical site infection (SSI) is one of the most common postoperative complications in patients undergoing major operations, such as spinal fusion surgery, and a major contributor to patient morbidity and mortality. SSI is considered the most preventable type of infection; however, the risk of SSI is multifactorial. This study aimed to determine the extent to which the expertise of the surgical first assistant (SFA) affected SSI rates. We retrospectively reviewed 528 patients at a single institution who underwent lumbar spine fusion surgery via the posterior approach performed by a single surgeon between January 2012 and May 2020. The SFAs participating in the surgeries were classified into 2 groups: a certified neurosurgery specialist and relatively less experienced neurosurgery resident trainees. To reduce potential selection bias and confounding factors, propensity score matching was performed between the 2 groups. In 170 of the 528 lumbar spine fusion surgeries, the SFA was a certified neurosurgery specialist. In the other 358 surgeries, the SFA was a resident trainee. Seventeen patients met the SSI criteria. The SSI rate was significantly different between the 2 groups (0.6% (1 patient) and 4.5% (16 patients) in the certified specialist and resident trainee groups, respectively; P = .02). After propensity score matching, 170 paired patients were selected. After adjusting for confounding factors, SFAs that were certified neurosurgery specialists were associated with a lower likelihood of SSI (adjusted OR 0.09; 95% CI, 0.01 to 0.79; P = .029) than SFAs that were neurosurgery residents. A higher level of SFA expertise was significantly associated with a lower overall SSI rate in lumbar spine fusion surgeries. It is difficult to predict the incidence of SSI; however, this finding suggests the importance of SFA expertise in preventing SSI.

Pseudoaneurysm formation or dural arteriovenous fistula formation at the middle meningeal artery following revascularization surgery in Moyamoya disease

Moyamoya disease (MMD) is a rare progressive steno-occlusive cerebrovascular disorder. Currently, revascularization surgery is used as optimal treatment to overcome MMD. However, revascularization for MMD has reported several complications. Also, iatrogenic complications such as pseudoaneurysms formation or dural arteriovenous fistulas (dAVFs) formation-has been identified in rare cases after the surgical intervention for revascularizations. We describe two cases. In first case, the patency of the anastomosis site was good and saccular type pseudoaneurysm formation was found at parietal branch of posterior middle meningeal artery (MMA) in transfemoral cerebral angiography (TFCA) performed on the twelfth day after surgery. We decided to treat pseudoaneurysm by endovascular embolization the next day, but the patient was shown unconsciousness and anisocoria during sleep at that day. Computed tomography showed massive subdural hemorrhage at the ipsilateral side, thus we performed decompressive craniectomy and hematoma evacuation. In second case, the patency of the anastomosis site was good and dAVF formation at right MMA was found in TFCA performed on the sixth day after surgery. We performed endovascular obliteration of the arteriovenous fistula under local anesthesia. Pseudoaneurysm formation or dAVF formation after revascularization surgery is an exceptional case. If patients have such complications, practioner should carefully screen the patients by implementing digital subtraction angiogram to identify anatomic features; as well as consider immediate treatment in any way, including embolization or other surgery.

The Influence of Neurological Disorders Before Cardiac Myxoma Surgery on the Rate of Postoperative Recurrences: Analysis of 317 Patients in a Single Center

BACKGROUND

Cardiac myxoma is a very rare disease for which resection is the gold standard treatment. Many neurological manifestations are associated with this disease, including embolic infarctions, arterial aneurysms, and brain metastatic myxomas, but few large-scale studies have addressed this. The aim of this study was to retrospectively analyze the incidence, type, and prognosis of these neurological disorders.

METHODS

We enrolled 317 patients who underwent a cardiac myxoma resection between 2004 and 2019 at our institution. A retrospective review of medical records and radiological imaging was performed for each patient, and clinical factors were compared and analyzed with regard to clinical outcomes and the incidence of adverse events.

RESULTS

Patients with a neurological disorder before surgery were found to be more likely to develop new postoperative neurological complications (P = 0.003). Patients with a neurological disorder arising at any time before or after surgery had poorer outcomes (P < 0.001).

CONCLUSIONS

The clinical management of cardiac myxoma must take account of neurological sequelae independently of the surgical intervention to remove the lesion. Patients with cardiac myxoma and any neurological disorder should undergo both neurosurgical follow-up and cardiac surgical follow-up, even if myxoma removal surgery has been performed. We recommend active neuroimaging during long-term follow-up as essential in these cases.

Clinical Interrogation of Mandatory Insertion of Central Venous Catheter for Clipping Surgery of Unruptured Intracranial Aneurysm: A Propensity Score Matched Study

BACKGROUND AND OBJECTIVE

Microsurgical clipping, along with endovascular treatment, has evolved in the treatment of unruptured intracranial aneurysms (UIA), and these developments have resulted in a reduction of the complication rate. We discuss the need for a central venous catheter (CVC) insertion as an anesthetic preparation for microsurgical clipping.

METHODS

Between January 2019 and September 2019, 722 patients with UIA were treated at our institution. We excluded patients with a history of endovascular treatment or bypass surgery, recurrent aneurysms after coil embolization, brain tumors, or subarachnoid hemorrhages. A total of 272 patients were enrolled. Eighty-four patients underwent CVC insertion, and 188 patients underwent clipping surgery without CVC insertion. Outcome-related factors were compared between the 2 groups. We performed propensity score matching of the 2 groups to increase comparability.

RESULTS

There were no significant differences in outcome, sex, aneurysm location, aneurysm multiplicity, aneurysm size, or comorbid disease between the 2 groups. The mean age at the time of surgery was higher in the non-CVC insertion group than in the CVC insertion group. There were no meaningful differences in primary outcomes, including premature rupture and intraoperative motor evoked potential/somatosensory evoked potential change, and secondary outcomes, including estimated blood loss, duration of intensive care unit stay, duration of hospitalization, and Glasgow Outcome Scale score at discharge.

CONCLUSIONS

CVC insertion for clipping surgery for UIA is not mandatory. Considering the possible complications associated with CVCs, we cautiously suggest aneurysm surgery with CVC insertion in patients with serious medical comorbidities, aneurysm sizes >10 mm, and difficult proximal parent artery control.

A case of endovascular treatment for followed by side to side bypass for vertebral artery dissecting aneurysms involved posterior inferior cerebellar artery

Treatment of complex aneurysms usually entails not only direct clipping but also alternative treatment modality. We recently experienced a case of vertebral artery dissecting aneurysm and obtained good treatment outcomes. Our case suggests that the endovascular segmental occlusion with posterior inferior cerebellar artery (PICA) to PICA side anastomosis might be a good treatment option in patients with complex vertebral artery dissecting aneurysms. A 45-year-old woman has a left vertebral dissecting aneurysm with dizziness. Based on the aneurysmal morphology and the involvement of PICA, the patient underwent side to side anastomosis of the PICA. This was followed by the endovascular segmental coil occlusion. The aneurysmal sac was completely obliterated. At a 2-year follow-up, the patient achieved a good patency of both PICA. In conclusion our case suggests that the endovascular segmental occlusion of the parent artery followed by PICA to PICA bypass surgery through a midline suboccipital approach is a reasonable multimodal treatment option in patients with complex vertebral artery dissecting aneurysms.

The usefulness of the ivy sign on fluid-attenuated intensity recovery images in improved brain hemodynamic changes after superficial temporal artery-middle cerebral artery anastomosis in adult patients with moyamoya disease

Objective

MR perfusion and single photon emission computerized tomography (SPECT) are well known imaging studies to evaluate hemodynamic change between prior to and following superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis in moyamoya disease. But their side effects and invasiveness make discomfort to patients. We evaluated the ivy sign on MR fluid attenuated inversion recovery (FLAIR) images in adult patients with moyamoya disease and compared it with result of SPECT and MR perfusion images.

Methods

We enrolled twelve patients (thirteen cases) who were diagnosed with moyamoya disease and underwent STA-MCA anastomosis at our medical institution during a period ranging from September of 2010 to December of 2012. The presence of the ivy sign on MR FLAIR images was classified as Negative (0), Minimal (1), and Positive (2). Regions were classified into four territories: the anterior cerebral artery (ACA), the anterior MCA, the posterior MCA and the posterior cerebral artery.

Results

Ivy signs on preoperative and postoperative MR FLAIR were improved (8 and 4 in the ACA regions, 13 and 4 in the anterior MCA regions and 19 and 9 in the posterior MCA regions). Like this result, the cerebrovascular reserve (CVR) on SPECT was significantly increased in the sum of CVR in same regions after STA-MCA anastomosis.

Conclusion

After STA-MCA anastomosis, ivy signs were decreased in the cerebral hemisphere. As compared with conventional diagnostic modalities such as SPECT and MR perfusion images, the ivy sign on MR FLAIR is considered as a useful indicator in detecting brain hemodynamic changes between preoperatively and postoperatively in adult moyamoya patients.

Two indices affecting the directions of the sylvian fissure dissection in middle cerebral artery bifurcation aneurysms

OBJECTIVE

This study proposes more objective methods for deciding the appropriate direction of the sylvian fissure dissection during surgical clipping in middle cerebral artery (MCA) bifurcation aneurysms.

METHODS

We reviewed data of 36 consecutive patients with MCA bifurcation aneurysms. We measured 2 indices preoperatively on 3-dimensional computed tomography angiography (3D-CTA). Analysis of the calculated data allowed us to select the appropriate direction of sylvian fissure dissection for ease of proximal control of M1. Statistically, Mann-Whitney test was used.

RESULTS

We classified subjects into 2 groups based on the technical level of M1 exposure during surgical clipping. When it was difficult to expose M1, subjects were assigned to Group I, and Group II were subjects in whom M1 exposure was easy. The mean difference between the distances extending from the limbus sphenoidale (LS) line to the internal carotid artery bifurcation and extending from the LS line to the MCA bifurcation was 1.00 ± 0.42 mm in group I and 4.39 ± 2.14 mm in group II. The mean M1 angle was 9.36 ± 3.73° in the group I and 34.05 ± 16.71° in the group II (M1 slope gap p < 0.05, M1 angle p < 0.05).

CONCLUSION

We have found an objective method for preoperatively verifying ease of exposure of M1 artery during surgical clipping. Therefore, we suggest use of the preoperative M1 slope gap and M1 angle as indicators in 3D-CTA selecting the direction of sylvian fissure dissection for easy proximal control of M1.

Chronic chorioamnionitis is the most common placental lesion in late preterm birth

OBJECTIVES

The pathogenesis of late preterm birth remains elusive for the mechanisms of disease responsible. Placental examination can often provide important clues for the pathogenesis of pregnancy complications. This study was conducted to determine placental pathologic findings according to the gestational age and the clinical circumstances of preterm birth.

STUDY DESIGN

Placental pathologic findings and obstetrical and neonatal outcomes were reviewed in a consecutive preterm birth cohort from a single tertiary center (N = 1206). Placentas of term births (N = 300) were used as normal controls.

RESULTS

Acute chorioamnionitis (22.7% vs. 16.7%), maternal vascular underperfusion (6.4% vs. 0.5%), and chronic chorioamnionitis (20.8% vs. 10.5%) were significantly more frequent in preterm births than in term births (P < 0.05, for each). Among preterm births, chronic chorioamnionitis was the most common pathology of late preterm birth (gestational age <37 and ≥34 weeks), while acute chorioamnionitis was the most common lesion of extremely preterm birth (gestational age <28 weeks). While the frequency of acute chorioamnionitis decreased with advancing gestation, that of chronic chorioamnionitis increased (P < 0.001, for each). The upward trend of the frequency of chronic chorioamnionitis was related to advancing gestation in both spontaneous and indicated preterm births (P < 0.001, for each).

CONCLUSIONS

Chronic chorioamnionitis is a common pathology of late preterm birth. It is suggested that chronic chorioamnionitis, a feature of maternal anti-fetal rejection, is an important etiology of preterm birth, especially of late preterm birth.

Meningeal layers around anterior clinoid process as a delicate area in extradural anterior clinoidectomy : anatomical and clinical study

Objective

Removal of the anterior clinoid process (ACP) is an essential process in the surgery of giant or complex aneurysms located near the proximal internal carotid artery or the distal basilar artery. An extradural clinoidectomy must be performed within the limits of the meningeal layers surrounding the ACP to prevent morbid complications. To identify the safest method of extradural exposure of the ACP, anatomical studies were done on cadaver heads.

Methods

Anatomical dissections for extradural exposure of the ACP were performed on both sides of seven cadavers. Before dividing the frontotemporal dural fold (FTDF), we measured its length from the superomedial apex attached to the periorbita to the posterolateral apex which connects to the anterosuperior end of the cavernous sinus.

Results

The average length of the FTDF on cadaver dissections was 7 mm on the right side and 7.14 mm on the left side. Cranial nerves were usually exposed when cutting FTDF more than 7 mm of the FTDF.

Conclusion

The most delicate area in an extradural anterior clinoidectomy is the junction of the FTDF and the anterior triangular apex of the cavernous sinus. The FTDF must be cut from the anterior side of the triangle at the periorbital side rather than from the dural side. The length of the FTDF incision must not exceed 7 mm to avoid cranial nerve injury.

Spontaneous cervical epidural hematoma causing brown-sequard syndrome

Spontaneous cervical epidural hematoma (SCEH) is a rare clinical entity and has a varied etiology. Urgent surgical decompression should be done to prevent serious permanent neurologic deficits. We describe a 59-year-old female who presented with Brown-Sequard syndrome due to spontaneous cervical epidural hematoma. Initially, she was misdiagnosed as cerebrovascular accident. Cervical magnetic resonance imaging revealed epidural hematoma to the right of the spinal cord extending from C3 to C6. She later underwent surgical evacuation and had complete restoration of neurologic function. The outcome in SCEH is essentially determined by the time taken from onset of the symptom to operation. Therefore, early and precise diagnosis such as careful history taking and MRI evaluation is mandatory.

A gene-specific primer extension and liquid bead array system for killer-cell immunoglobulin-like receptor genotyping

A simple and accurate method for killer-cell immunoglobulin-like receptor (KIR) genotyping is developed using KIR gene-specific primer extension (GSPE) followed by bead array hybridization (GSPE method). After amplification of exons 4, 5, and 9, KIR GSPE and bead array hybridization were performed to verify the presence or absence of 16 KIR subfamilies. GSPE method was validated with natural killer/KIR reference panel I consisting of 48 cell types provided by 13th International Histocompatibility Working Group (IHWG) and genomic DNA from 17 peripheral blood cells, 8 cell lines, and 8 buccal cells. The results of reference panel from GSPE method were 100% concordant with the IHWG reference typing information. All genomic DNAs except reference panel were typed for KIR genes with sequence-specific primer methods and showed 100% identical typing results using this novel system. In addition, GSPE method can obtain results in 8 h from DNA with 10 ng genomic DNA in a 96-well-based assay format.

Histologic chorioamnionitis is more common after spontaneous labor than after induced labor at term

OBJECTIVE

Inflammation of the chorioamniotic membranes (histologic chorioamnionitis) is a risk factor for adverse neonatal outcome. Labor has many common features with inflammatory processes; therefore, an important question is whether the frequency of histologic chorioamnionitis in spontaneous labor at term is higher than that of women in labor after induction. This study was conducted to address this question.

STUDY DESIGN

The frequency of histologic chorioamnionitis was compared between patients who delivered after the spontaneous onset of labor versus those who delivered after induction of labor at term in singleton gestations (> or = 37 weeks). Patients in whom uterotonic agents were used during the latent phase of labor were excluded.

RESULTS

(1) The overall frequency of histologic chorioamnionitis was 20.2% (107/531); (2) histologic chorioamnionitis was significantly more frequent in women who delivered after the spontaneous onset of labor than in those who underwent induction of labor (24.3% [81/333] versus 13.1% [26/198], p < 0.005). This difference remained significant after adjusting for parity, gestational age at delivery, total duration of labor, the interval from rupture of membranes to delivery and the mode of delivery.

CONCLUSION

Histologic chorioamnionitis is more common in women who delivered after the spontaneous onset of labor than in those who underwent induction of labor at term.

Unexplained fetal death is associated with changes in the adaptive limb of the maternal immune response consistent with prior antigenic exposure

OBJECTIVE

The causes of fetal death are largely unknown. CD4 T cells have been classified according to the expression of the CD45 isoforms into 'naive-like' T cells (CD45RA) and 'memory-like' T cells (CD45RO). An increase in the percentage of the CD45RO has been interpreted as indicating prior antigenic exposure of the host and, in newborns, evidence of infection. The purpose of this study was to determine whether unexplained fetal death was associated with a change in the proportion of 'naive-like' and 'memory-like T cells' in the maternal blood, as determined by the CD45 isoforms on the surface of CD4+ lymphocytes.

STUDY DESIGN

A prospective study was conducted to compare the CD45 sub-population of lymphocytes in patients with intrauterine fetal death (n = 26) and normal pregnancy (n = 89). The percentages of CD45RA+, CD45RO+ and CD45RA+/CD45RO+ on CD4+ T lymphocytes were determined in maternal blood using flow cytometry and monoclonal antibodies. Results were reported as a percentage of CD4+ lymphocytes. Non-parametric statistics were used for analysis. A p value of < 0.05 was considered significant.

RESULTS

Patients with intrauterine fetal death had a higher percentage of CD45RO+ CD4+ T lymphocytes than normal pregnant women (fetal death: median 57.7%, range 35.4-78.6 vs. normal pregnancy: median 49.9%, range 19.1-86.8; p = 0.004). Fetal death was associated with a lower median percentage of CD45RA+ CD4+ lymphocytes than in normal pregnant women (fetal death: median 32.3%, range 15.3-58.0 vs. normal pregnancy: median 40.2%, range 11.2-67.3; p = 0.01). There was no significant difference in the percentage of cells with dual expression (CD45RA+/CD45RO+) between the study groups.

CONCLUSION

Prior exposure to microbial products (bacterial or viral) or other unidentified antigens may result in a shift of the sub-population of 'naive-like' T cells to 'memory-like' T cells in mothers with unexplained fetal death.

The frequency and clinical significance of intra-uterine infection and inflammation in patients with placenta previa and preterm labor and intact membranes

OBJECTIVE

Histologic placental and/or intra-amniotic inflammation is frequently documented during ascending intra-uterine infections in patients with preterm labor and intact membranes. Placenta previa can be a clinical situation that shows the successive schema of histologic placental and intra-amniotic inflammation during the process of ascending intra-uterine infections. However, a paucity of information exists about the frequency and clinical significance of intra-uterine infections and inflammation in patients with placenta previa and preterm labor and intact membranes. The purpose of this study was to examine this issue.

STUDY DESIGN

Amniocentesis was performed on 42 patients with placenta previa and preterm labor and intact membranes (gestational age <37 weeks). Amniotic fluid (AF) was cultured for aerobic and anaerobic bacteria and genital mycoplasmas, and AF white blood cell (WBC) count and matrix metalloproteinase-8 (MMP-8) concentrations were determined. The diagnosis of intra-amniotic inflammation was made in patients with an elevated AF MMP-8 (> or =23 ng/ml). Non-parametric statistics were used for analysis.

RESULTS

1) Intra-amniotic inflammation was present in 16.7% (7/42), proven AF infection in 4.9% (2/41), and histologic chorioamnionitis in 19.0% (8/42) of patients with placenta previa and preterm labor; 2) Patients with intra-amniotic inflammation had significantly higher rates of a positive AF culture, histologic chorioamnionitis, funisitis, and a shorter interval-to-delivery than those without intra-amniotic inflammation (p<0.05 for each); 3) Among patients with histologic chorioamnionitis, inflammation of the choriodecidua, which was exposed to the cervical canal, existed in all cases (8/8), but inflammation of the chorionic plate existed in 63% of patients (5/8); 4) Patients with inflammation of the chorionic plate had significantly higher median AF MMP-8 concentrations and WBC counts, and higher rates of intra-amniotic inflammation than those in whom inflammation was restricted to choriodecidua (p<0.05 for each).

CONCLUSIONS

Placental inflammation was present in 19.0% and intra-amniotic inflammation was present in 16.7% of patients with placenta previa and preterm labor and intact membranes. The intra-amniotic inflammatory response was stronger when inflammation was present in the chorionic plate and choriodecidua, than when it was restricted to the choriodecidua only, which was exposed to the cervical canal in placenta previa.

Distribution of CD14+ and CD68+ Macrophages in the Placental Bed and Basal Plate of Women With Preeclampsia and Preterm Labor

OBJECTIVE

Macrophages play a key role in implantation, placentation and parturition. Yet, whether or not the number of macrophages at the fetomaternal interface (basal plate of the placenta and placental bed) is altered in women with preeclampsia is the subject of controversy. The purpose of this study was to compare the immunoreactivity and distribution patterns of CD14 and CD68 positive macrophages in both the basal plate and placental bed from preeclamptic and non-preeclamptic pregnancies.

METHODS

A cross-sectional study was conducted. Paraffin embedded sections of placental tissues and placental bed biopsies were obtained from patients with early onset preeclampsia (n=10) and from those with preterm labor/delivery (n=10) without preeclampsia matched for gestational age. Double immunohistochemistry using antibodies to CD14 and CD68 was performed, and the density of double or single positive cells in the basal plate and placental bed was evaluated. Non-parametric statistics were used for analysis.

RESULTS

1) A unique subset of CD14-/CD68+ cells was identified. The cells in question were present at a higher level in the decidua than in the myometrial segment of the placental bed (p<0.01); 2) The density and proportion of CD14+/CD68+ cells (double positive cells) were significantly higher in the myometrial segment than in the basal plate (p=0.0003); and 3) There were no significant differences in the density and patterns of immunopositive macrophages in the basal plate, the decidua, and the myometrium between women with preeclampsia and those with preterm labor/delivery (p>0.05).

CONCLUSION

The macrophages at the fetomaternal interface can be dichotomized by CD14 and CD68 immunoreactivity. A gradient of CD14+/CD68+ macrophages was demonstrated between the superficial myometrium and the basal plate regardless of the etiology of preterm birth (preeclampsia or spontaneous preterm labor). The biological function of single positive (CD14-/CD68+) and double positive (CD14+/CD68+) macrophages at the fetomaternal interface remains to be established. The overall findings also suggest that the discrepancies in the literature are due to the varying markers used to detect macrophages and in the anatomical plane of the fetomaternal junction analyzed.

Multicentre, parallel group, randomised, single-blind study of the safety and efficacy of atosiban versus ritodrine in the treatment of acute preterm labour in Korean women

OBJECTIVE

To compare the efficacy and safety of atosiban with those of ritodrine in preterm labour.

DESIGN

Multicentre, single-blind, randomised, controlled trial.

SETTING

Obstetric units in six referral centres in Korea.

POPULATION

Women with singleton pregnancies with preterm labour, between 24 and 33 + 6 weeks of gestation.

METHODS

One hundred and twenty-eight women were randomised to receive intravenous atosiban (n= 63) or ritodrine (n= 65) and were stratified by gestational age (<28 weeks and >or=28 weeks). Atosiban or ritodrine was administered for up to 48 hours. Progression of labour was assessed by the frequency of contractions and cervical dilatation and effacement. Alternative tocolysis could be given as rescue therapy.

MAIN OUTCOME MEASURE

Efficacy was assessed as the proportion of women in each group who did not deliver and did not need alternative tocolytic therapy at 48 hours and 7 days after therapy initiation. Safety was assessed as the numbers of maternal adverse events and neonatal morbidity.

RESULTS

Tocolytic efficacy after 7 days was significantly better in the atosiban group than in the ritodrine group (60.3 versus 34.9%), but not at 48 hours (68.3 versus 58.7%). Maternal adverse events related to therapy were reported less frequently in the atosiban group (7.9 vs 70.8%; P= 0.0001), resulting in fewer early drug terminations due to adverse events (0 versus 20.0%; P= 0.0001). This, however, was not accompanied by a concurrent improvement in perinatal outcomes.

CONCLUSION

The efficacy and safety of atosiban in the treatment of preterm labour were superior to those of ritodrine.

Fetal cardiac dysfunction in preterm premature rupture of membranes

BACKGROUND

Preterm premature rupture of membranes (PROM) is associated with one-third of preterm births. In about 50% of preterm PROM cases, the fetuses will elicit a fetal inflammatory response syndrome (FIRS). FIRS is associated with the impending onset of preterm labor, periventricular leukomalacia, neonatal sepsis, and long-term handicap, including the development of bronchopulmonary dysplasia and cerebral palsy. The fetal myocardium is a potential target organ of proinflammatory cytokines released during FIRS. The objective of this study was to determine whether preterm PROM is associated with functional changes in the fetal heart, as determined by fetal echocardiography.

METHODS

A retrospective study was conducted to assess the diastolic function of fetuses with preterm PROM with documented microbial invasion of the amniotic cavity (n = 25), preterm PROM without microbial invasion of the amniotic cavity (n = 42), and fetuses from normal pregnancies (control group = 150). Pregnancies with multiple gestation, fetal distress, fetuses that were small for gestational age, and major congenital anomalies were excluded. Fetal echocardiography studies were performed with two-dimensional ultrasound, color Doppler imaging and pulsed Doppler ultrasound. Non-parametric statistics were used for comparisons. A p value of < 0.05 was considered significant.

RESULTS

The prevalence of positive amniotic fluid cultures for micro-organisms in patients with preterm PROM was 35.8% (24/67). Ureaplasma urealyticum was the most frequent isolate, either alone (41.7%; 10/24) or with other micro-organisms (29.2%; 7/24). Fetuses with preterm PROM had a higher delta early diastolic filling/atrial contraction (E/A) peak velocity ratio, a higher delta E/A velocity-time integral (VTI) ratio, a lower delta A peak velocity, a lower delta A VTI, and a lower A VTI/total VTI ratio in the mitral valve compared to those with uncomplicated pregnancies. The delta E/A peak velocity ratio was significantly higher and the delta A VTI significantly lower in fetuses with preterm PROM and microbial invasion of the amniotic cavity than in those with preterm PROM without microbial invasion of the amniotic cavity.

CONCLUSIONS

Preterm PROM is associated with changes in fetal cardiac function consistent with increased left ventricular compliance. These observations were also noted in fetuses with microbial invasion of the amniotic cavity. Our findings suggest that fetal cardiac function is altered in preterm PROM and, in particular, in cases with intra-amniotic infection.

The prevalence and clinical significance of amniotic fluid 'sludge' in patients with preterm labor and intact membranes

OBJECTIVE

To determine the prevalence and clinical significance of amniotic fluid (AF) 'sludge' observed during transvaginal ultrasound examination of the cervix in patients with preterm labor and intact membranes, and in those with uncomplicated pregnancies.

METHODS

This retrospective study included patients with preterm labor and intact membranes (n = 84) and those with uncomplicated term pregnancies (n = 298). The outcome variables included the occurrence of documented microbial invasion of the amniotic cavity (MIAC), histological chorioamnionitis, examination-to-delivery interval, admission to the neonatal intensive care unit (NICU), a composite neonatal morbidity, perinatal death, and delivery within 48 h, 7 days, and < 35 weeks and < 32 weeks. Statistical analysis included Chi-square test, stepwise logistic regression analysis and survival analysis.

RESULTS

The prevalence of AF 'sludge' was 1% (3/298) in patients with uncomplicated term pregnancies and 22.6% (19/84) in those with preterm labor and intact membranes. Among patients with preterm labor and intact membranes: (1) cervical length < or = 15 mm was present in 58.3% (49/84) of the patients; (2) the prevalence of MIAC and histological chorioamnionitis was 12.1% (7/58) and 32.9% (25/76), respectively; (3) the rate of spontaneous preterm delivery within 48 h, 7 days, and < 32 weeks and < 35 weeks of gestation was 13.6% (8/59), 28.8% (17/59), 39.5% (17/43) and 50.8% (30/59), respectively; (4) patients with AF 'sludge' had a higher frequency of positive AF cultures [33.3% (6/18) vs. 2.5% (1/40), P = 0.003] and histological chorioamnionitis [77.8% (14/18) vs. 19% (11/58), P < 0.001] than those without AF 'sludge'; (5) a higher proportion of neonates born to patients with AF 'sludge' was admitted to the NICU [64.3% (9/14) vs. 12.9% (8/62), P < 0.01], had a composite neonatal morbidity [36.8% (7/19) vs. 13.8% (9/65), P = 0.04] and died in the perinatal period [36.8% (7/19) vs. 4.6% (3/65), P = 0.001] than those born to women without 'sludge'; (6) a higher proportion of patients with AF 'sludge' had spontaneous delivery within 48 h [42.9% (6/14) vs. 4.4% (2/45), P = 0.001], within 7 days [71.4% (10/14) vs. 15.6% (7/45), P < 0.001], < 32 weeks [75% (9/12) vs. 25.8% (8/31), P = 0.005] and < 35 weeks [92.9% (13/14) vs. 37.8% (17/45), P < 0.001] than those without AF 'sludge'; and (7) patients with AF 'sludge' had a shorter examination-to-delivery interval than those without AF 'sludge' [AF 'sludge' median, 1 (IQR, 1-5) days vs. no AF 'sludge' median, 33 (IQR, 18-58) days; P < 0.001].

CONCLUSION

The presence of AF 'sludge' in patients with preterm labor and intact membranes is a risk factor for MIAC, histological chorioamnionitis and impending preterm delivery.

Neonates born to pre-eclamptic mothers have a higher percentage of natural killer cells (CD3-/CD56+16+) in umbilical cord blood than those without pre-eclampsia

OBJECTIVE

Maternal endothelial dysfunction and intravascular inflammation have been implicated in the mechanisms of disease responsible for the clinical syndrome of pre-eclampsia. Recently, the activation of the innate limb of the immune response (neutrophils and monocytes) in the fetal circulation has been reported in neonates born to mothers with pre-eclampsia. Natural killer (NK) cells are identified morphologically as a subpopulation of lymphocytes, but functionally as one component of the innate immune system. NK cells participate in the control of viral or bacterial infection, regulation of hematopoiesis, production of cytokines and cytotoxicity of neoplastic cells. Accumulating evidence suggests that the innate system is required for mounting an adequate adaptive response. NK cells, originally defined as effector cells of the innate immune system, may also play a role as regulatory cells for the adaptive immune system. This study was designed to determine the proportion of the NK cell subset of lymphocytes in umbilical cord blood of neonates born to mothers with and without pre-eclampsia.

METHODS

A cross-sectional study including neonates of mothers with (n = 48) and those without pre-eclampsia (control group) (n = 72) was conducted. Pre-eclampsia was diagnosed in the presence of hypertension and proteinuria. The control group consisted of neonates (premature and term) with no evidence of acute inflammation within the extraplacental membranes (chorioamnionitis). Umbilical cord blood was collected at the time of delivery, and assayed using monoclonal antibodies for selective cluster differentiation (CD) antigens in order to determine the proportion of NK cells as a percentage of total lymphocytes. The immunophenotypic characteristic was determined using flow cytometry, and NK cells were identified by positivity of CD16 and CD56 without CD3 (CD3-/CD56+16+). Log transformation of the percentage of NK cells was performed. Parametric statistics were used for analysis. Multiple regression analysis was utilized to examine the contribution of potentially confounding factors on the proportion of NK cells. A p value of < 0.05 was considered statistically significant.

RESULTS

Neonates born to mothers with pre-eclampsia had a significantly higher percentage of NK cells (CD3-/CD56+16+) than those in the control group (pre-eclampsia, mean +/- SD 17 +/- 9% vs. control, mean +/- SD 12 +/- 7.5%; p = 0.001). Multiple regression analysis suggested that umbilical cord blood pH of < 7.2, labor with vaginal delivery and maternal pre-eclampsia were associated with an increased percentage of NK cells in umbilical cord blood.

CONCLUSIONS

Pre-eclampsia is associated with a higher NK cell (CD3-/CD56+16+) subset of lymphocytes in umbilical cord blood than in the control group. This difference cannot be explained by fetal acidosis or the presence of labor.

Maternal and fetal inflammatory responses in unexplained fetal death

OBJECTIVE

The role of intra-amniotic infection in the etiology of fetal death has been proposed. This study was conducted to determine the prevalence of microbial invasion of the amniotic cavity (MIAC) and the frequency of maternal and/or fetal inflammation in patients presenting with a fetal death.

METHODS

A prospective study was conducted in patients with a fetal death. Amniocenteses were performed for clinical indications (karyotype), as well as to assess the microbiological and cytological state of the amniotic cavity. Fluid was cultured for aerobic and anaerobic bacteria and genital mycoplasmas. An amniotic fluid white blood cell count and glucose determinations were also performed. Histological examination of the placenta was conducted to identify a maternal inflammatory response (acute chorioamnionitis) or a fetal inflammatory response (funisitis).

RESULTS

This study included 44 patients with intrauterine fetal death. The median gestational age at diagnosis was 30.1 weeks (range 16.3-40.4 weeks). One patient had documented MIAC (1/44). Acute histological chorioamnionitis was found in 20.9% (9/43), but a fetal inflammatory response was observed in only 2.3% (1/43) of cases. One patient had a positive amniotic fluid culture for Streptococcus agalactiae (group B streptococcus).

CONCLUSION

Histological chorioamnionitis was present in 20.9% of cases, but MIAC could be demonstrated with conventional microbiological techniques in only one case. A fetal inflammatory response was nine times less frequent than a maternal inflammatory response (maternal 20.9% vs. fetal 2.3%, p = 0.008) in cases of fetal death.

C-reactive protein in umbilical cord blood: a simple and widely available clinical method to assess the risk of amniotic fluid infection and funisitis

OBJECTIVE

The purpose of this study was to determine whether concentrations of C-reactive protein (CRP) in umbilical cord plasma at birth were elevated in neonates with sepsis, an inflammatory lesion of the umbilical cord (funisitis) or who were born to mothers with microbial invasion of the amniotic cavity.

METHODS

Umbilical cord plasma was collected at birth from 313 singleton preterm neonates (20-35 weeks of gestation). The results of amniotic fluid culture performed within 5 days of birth, the occurrence of congenital neonatal sepsis and the presence of funisitis were assessed. Amniocentesis was performed in 152 patients within 5 days of birth. Amniotic fluid was cultured for aerobic and anaerobic bacteria and for mycoplasmas. The CRP concentration was measured with a highly sensitive immunoassay.

RESULTS

The median cord plasma CRP concentration was significantly higher in neonates with a positive amniotic fluid culture than in those with negative culture (median 245.9 (range 11.6-4885.5) ng/ml vs. median 44.3 (range 2.3-7401.8) ng/ml; p < 0.001), in those with congenital proven sepsis than in those without this complication (median 789.5 (range 20.4-2584.3) ng/ml vs. median 41.5 (range 1.3-7401.8) ng/ml; p < 0.005) and in neonates with funisitis than in those without funisitis (median 403.8 (range 4.9-10897.4) ng/ml vs. median 31.0 (range 1.3-7401.8) ng/ml; p < 0.001). The sensitivity of CRP in the identification of amniotic fluid infection, neonatal sepsis and funisitis was similar to that of interleukin-6 (> 17.5 pg/ml). However, the specificity of CRP in the identification of neonatal sepsis and funisitis was significantly higher than that of interleukin-6 (74% vs. 69%, p < 0.05; 83% vs. 76%, p < 0.01).

CONCLUSION

Umbilical cord plasma CRP concentrations were elevated in patients with amniotic fluid infection, congenital neonatal sepsis and funisitis.

Retinoic acid-mediated induction of neurons and glial cells from human umbilical cord-derived hematopoietic stem cells

Recent studies reporting trans-differentiation of mononucleated cells derived from human umbilical cord blood into neuronal cells aroused interest among investigators for their clinical implication and significance in regenerative medicine. In the present study, purified populations of hematopoietic stem cells were isolated via magnetic bead sorting and fluorescence-activated cell sorter (FACS) using a specific CD133 antibody, a cell type-specific marker for hematopoietic stem cells, and grown in culture in the presence of retinoic acid (RA). CD133+ hematopoietic stem cells expressed neuronal and glial phenotypes after RA treatment. RT-PCR analysis indicated that the RA treated CD133+ cells expressed mRNA transcripts for ATP-binding cassettes transporter ABCG2 (a universal stem cell marker), nestin (a specific cell type marker for neural stem cells), Musashi1 (a specific marker for neural stem cells) and RA receptors (RAR) including RAR-alpha, RAR-beta, and retinoid X receptor (RXR)-gamma. RA-treated CD133+ cells expressed mRNA transcripts for neuron-specific markers neurofilament proteins (NF-L, -M, -H) and synaptophysin as determined by RT-PCR, structural proteins characteristic of neurons including tubulin beta III and neuron specific enolase (NSE) by Western blot, and neuron-specific markers NeuN and microtubule-associated protein-2 (MAP2) by immunocytochemistry. RA-treated CD133+ cells also expressed the astrocyte-specific marker glial fibrillary acidic protein (GFAP), as demonstrated by RT-PCR, Western blot, and immunocytochemistry. In addition, RA-treated CD133+ cells expressed cell type-specific markers for oligodendrocytes including myelin basic protein (MBP) as shown by RT-PCR, proteolipid protein (PLP) by Western blot analysis, and cyclic nucleotide phosphodiesterase (CNPase) by immunostaining. Upregulated expression of several basic helix-loop-helix (bHLH) transcription factors important for early neurogenesis, including Otx2, Pax6, Wnt1, Olig2, Hash1 and NeuroD1, was also demonstrated in CD133+ cells after RA treatment. These results indicate that human cord blood-derived CD133+ hematopoietic stem cells could trans-differentiate into neural cell types of neuron-like cells, astrocytes, and oligodendrocytes by RA treatment.

Differences in the fetal interleukin-6 response to microbial invasion of the amniotic cavity between term and preterm gestation

BACKGROUND/OBJECTIVE

Fetal inflammatory response has been implicated as a mechanism of multi-system organ injury in preterm and term neonates. Microbial invasion of the amniotic cavity (MIAC) is frequently associated with a fetal inflammatory response. However, there are no studies comparing the fetal response to MIAC in term and preterm gestations. The purpose of this study was to compare the umbilical cord plasma interleukin-6 (IL-6) concentrations in term and preterm neonates in the presence or absence of MIAC.

STUDY DESIGN

Umbilical cord blood was obtained at birth from 252 neonates whose mothers had an amniocentesis within 48 h of delivery (preterm delivery, n = 62; term delivery, n = 190). MIAC was defined as a positive amniotic fluid culture for bacteria or genital mycoplasmas. IL-6 was measured by a sensitive and specific immunoassay.

RESULTS

The median IL-6 concentration in umbilical cord plasma was significantly higher in preterm neonates than in term neonates (median 13.4 pg/ml, range 0.1-676 pg/ml vs. median 3.2 pg/ml, range 0.1-408 pg/ml; p < 0.0001). In the context of MIAC, the median umbilical cord plasma IL-6 concentration was significantly higher in preterm than in term neonates (median 31.6 pg/ml, range 1.4-676 pg/ml vs. median 11.7 pg/ml, range 1.3-82 pg/ml, respectively; p < 0.05). Neonates born to mothers with a positive amniotic fluid culture had a significantly higher median IL-6 concentration than neonates born to mothers with a negative amniotic fluid culture (preterm: median 31.6, range 1.4-676 pg/ml vs. median 8.0, range 0.1-656 pg/ml; p < 0.05 and term: median 11.7, range 1.3-82 pg/ml vs. median 3.1, range 0.1-408 pg/ml; p < 0.01, respectively).

CONCLUSIONS

The preterm fetus is capable of mounting a systemic cytokine response as measured by IL-6 in its peripheral blood. In the setting of MIAC, a fetal IL-6 response is higher in preterm than in term gestation.

Antimicrobial peptides in amniotic fluid: defensins, calprotectin and bacterial/permeability-increasing protein in patients with microbial invasion of the amniotic cavity, intra-amniotic inflammation, preterm labor and premature rupture of membranes

OBJECTIVE

Neutrophil defensins (HNP 1-3), bactericidal/permeability-increasing protein (BPI) and calprotectin (MRP8/14) are antimicrobial peptides stored in leukocytes that act as effector molecules of the innate immune response. The purpose of this study was to determine whether parturition, premature rupture of the membranes (PROM) and microbial invasion of the amniotic cavity (MIAC) are associated with changes in amniotic fluid concentrations of these antimicrobial peptides.

STUDY DESIGN

Amniotic fluid was retrieved by amniocentesis from 333 patients in the following groups: group 1, mid-trimester with a subsequent normal pregnancy outcome (n = 84); group 2, preterm labor and intact membranes without MIAC who delivered at term (n = 36), or prematurely (n = 52) and preterm labor with MIAC (n = 26); group 3, preterm PROM with (n = 26) and without (n = 26) MIAC; and group 4, term with intact membranes in the absence of MIAC, in labor (n = 52) and not in labor (n = 31). The concentrations of HNP 1-3, BPI and calprotectin in amniotic fluid were determined by specific and sensitive immunoassays. Placentae of patients in both preterm labor with intact membranes and preterm PROM groups who delivered within 72 h of amniocentesis were examined. Non-parametric statistics, receiver-operating characteristic (ROC) curves and Cox regression models were used for analysis. A p value of < 0.05 was considered statistically significant.

RESULTS

Intra-amniotic infection was associated with a significant increase in amniotic fluid concentrations of immunoreactive HNP 1-3, BPI and calprotectin in both women with preterm labor and intact membranes, and women with preterm PROM. Preterm PROM was associated with a significant increase in amniotic fluid concentrations of immunoreactive HNP 1-3, BPI and calprotectin. Preterm parturition was associated with a significant increase in amniotic fluid concentrations of immunoreactive HNP 1-3, BPI and calprotectin, while parturition at term was associated with a significant increase in amniotic fluid concentrations of immunoreactive HNP 1-3. Among patients with preterm labor and intact membranes, elevation of amniotic fluid HNP 1-3, BPI and calprotectin concentrations was associated with intra-amniotic inflammation, histological chorioamnionitis and a shorter interval to delivery.

CONCLUSION

MIAC, preterm parturition and preterm PROM are associated with increased amniotic fluid concentrations of immunoreactive HNP 1-3, BPI and calprotectin. Moreover, elevated amniotic fluid concentrations of BPI, immunoreactive HNP 1-3 and calprotectin are associated with intra-amniotic inflammation, histological chorioamnionitis and shorter amniocentesis-to-delivery interval in patients presenting with preterm labor with intact membranes.

Evidence of participation of soluble CD14 in the host response to microbial invasion of the amniotic cavity and intra-amniotic inflammation in term and preterm gestations

OBJECTIVE

Endotoxin has been implicated in the mechanism responsible for the setting of infection in preterm labor. To exert its biological effects, endotoxin binds to a circulating protein known as lipopolysaccharide binding protein (LBP) and presents endotoxin monomers to CD14, which may be a membrane-bound receptor or a soluble molecule. The endotoxin-LBP-CD14 complex interacts with Toll-like receptor 4 and other regulatory proteins leading to cellular activation and an inflammatory response. The purpose of this study was to determine whether microbial invasion of the amniotic cavity (MIAC)/intra-amniotic inflammation (both preterm and term) and parturition at term are associated with changes in the amniotic fluid and umbilical plasma soluble concentrations of CD14 (sCD14).

STUDY DESIGN

Amniotic fluid was retrieved by amniocentesis from 88 patients in the following groups: group 1, preterm labor with intact membranes with MIAC/intra-amniotic inflammation (n = 18) and without these conditions (n = 26); group 2, term gestations not in labor without MIAC/intra-amniotic inflammation (n = 11), in labor without MIAC/intra-amniotic inflammation (n = 12) and in labor with MIAC/intra-amniotic inflammation (n = 13); and group 3, patients who underwent genetic amniocentesis at mid-trimester (n = 8). A sample of cord blood was obtained after delivery in all patients except those in group 3. sCD14 was assayed with a sensitive and specific immunoassay. Non-parametric statistics were used for analysis. A p value of < 0.05 was considered significant.

RESULTS

sCD14 was detectable in 97% (85/88) of the amniotic fluid samples. Amniotic fluid sCD14 concentrations were lower in patients at term than in the mid-trimester of pregnancy (mid-trimester: median 482 ng/ml, range 258-838 ng/ml vs. term no labor: median 7 ng/ml, range 2-274 ng/ml, p = 0.01). Among patients with preterm labor with intact membranes, the median amniotic fluid sCD14 level of patients with MIAC/intra-amniotic inflammation was higher than in patients without these conditions (median 1568 ng/ml, range 98-5887 ng/ml vs. median 645 ng/ml, range 0-3961 ng/ml, respectively; p = 0.01). Among women at term in labor, those with MIAC/intra-amniotic inflammation had a higher median amniotic fluid sCD14 concentration than those without these conditions (median 85 ng/ml, range 2-1113 ng/ml vs. median 17 ng/ml, range 0-186 ng/ml; p = 0.01). MIAC/intra-amniotic inflammation in women with preterm labor with intact membranes was associated with a higher median umbilical venous plasma sCD14 concentration (median 744 ng/ml, range 0-3620 ng/ml vs. median 0 ng/ml, range 0-2060 ng/ml; p = 0.04). sCD14 was undetectable in plasma from umbilical cords of all neonates born to women at term. An increase in amniotic fluid concentration of sCD14 was observed in cases of intrauterine infection, not only by gram-negative bacteria, but also gram-positive bacteria and Ureaplasma spp.

CONCLUSION

sCD14 is a physiological constituent of amniotic fluid, and its concentrations at term are lower than in the mid-trimester. Intrauterine infection/inflammation is associated with a higher median amniotic fluid sCD14 concentration in both preterm and term parturition. Neonates born from mothers with preterm labor with intact membranes and MIAC/intra-amniotic inflammation had a higher median concentration of sCD14 in umbilical cord plasma than those without these conditions. sCD14 concentrations are increased in the amniotic fluid and umbilical cord blood even in the absence of a microbiologically proven gram-negative infection. CD14 appears to participate in the host response to intrauterine infection even in cases involving genital mycoplasmas.

Subclinical myocardial injury in small-for-gestational-age neonates

OBJECTIVE

Small-for-gestational-age (SGA) infants are at risk for premature death from cardiovascular disease (myocardial infarction and stroke), hypertension, and diabetes in adult life. Severe intrauterine growth restriction is often associated with subclinical cardiovascular abnormalities detectable during fetal echocardiography. The objective of this study was to determine whether SGA newborns have evidence of myocardial injury at birth.

STUDY DESIGN

Cardiac troponin I, a specific marker of myocardial injury widely used for the diagnosis of myocardial infarction in adults, was determined in umbilical cord blood. Umbilical cord venous blood was obtained at the time of birth from 72 SGA newborns (birth weight below the 10th centile for gestational age) and 309 newborns whose birth weights were appropriate for gestational age (AGA). Cardiac troponin I was determined with a commercially available immunoassay (sensitivity 0.2 ng/ml) employed in clinical laboratories (Immulite 2000, Diagnostic Products Corp., Los Angeles, CA).

RESULTS

Cardiac troponin I was not detectable in any of the blood samples from AGA infants. In contrast, 4.2% (3/72) of SGA infants had detectable cardiac troponin I in umbilical cord blood (Fisher's exact test, p = 0.007).

CONCLUSION

A subgroup of SGA newborns undergoes myocardial injury before birth. This insult may predispose to the development of adult premature cardiovascular disease and death.

Activation of coagulation system in preterm labor and preterm premature rupture of membranes

OBJECTIVE

Thrombin, originally discovered as a coagulation factor, is a multifunctional protease capable of inducing myometrial contractions in vitro and in vivo. This enzyme has been implicated in the mechanisms of premature labor. Plasma concentrations of thrombin-antithrombin (TAT) complexes are an index of in vivo thrombin generation. The purpose of this study was to determine whether patients with premature labor and preterm premature rupture of membranes (PROM) have evidence of increased thrombin generation in maternal blood, as determined by the TAT complex concentrations.

METHODS

A cross-sectional study was designed to determine plasma concentrations of TAT complexes in 110 women in the following groups: non-pregnant women (n = 20); normal pregnant women (n = 30); women in preterm labor with intact membranes (n = 30); and women with preterm PROM (n = 30). TAT complex concentrations were determined with a sensitive and specific immunoassay. Statistical analysis was conducted with non-parametric statistics.

RESULTS

Patients with preterm labor and intact membranes had a significantly higher median plasma TAT complex concentration than normal pregnant women (women in preterm labor, median 19.1 microg/l; range 7.4-406 vs. normal pregnant women, median 15 microg/l; range 6.8-32.5; p = 0.03). Patients with preterm PROM had a higher median TAT complex concentration than normal pregnant women (preterm PROM, median 19.1 microg/l; range 4.7-738.6 vs. normal pregnant women, median 15 microg/l; range 6.8-32.5; p = 0.03). Normal pregnancy was associated with a higher median plasma TAT complex concentration than the non-pregnant state (normal pregnant women, median 15 microg/l; range 6.8-32.5 vs. non-pregnant women, median 2.7 microg/l; range 0.9-14.2; p < 0.001).

CONCLUSION

Preterm labor and preterm PROM are associated with an excess generation of thrombin.

Evidence of in vivo generation of thrombin in patients with small-for-gestational-age fetuses and pre-eclampsia

OBJECTIVE

Thrombotic lesions in the maternal or fetal compartments are frequently observed in the placentas of patients with small-for-gestational-age (SGA) fetuses and in pre-eclampsia. The objective of this study was to determine whether there was evidence of in vivo generation of thrombin, the rate-limiting enzyme responsible for the formation of fibrin. The plasma concentrations of thrombin-antithrombin (TAT) complexes were used as an index of thrombin generation.

METHODS

TAT complexes were measured in the plasma from 68 women from the following groups: normal pregnancy (n = 29); pre-eclampsia (n = 26); and SGA (defined as estimated fetal weight below the 10th centile for gestational age, which was confirmed by neonatal birth weight) (n = 13). TAT complex plasma concentrations were determined with a specific and sensitive immunoassay. Statistical analysis was performed with non-parametric statistics.

RESULTS

The median plasma TAT complex concentrations were significantly higher in patients who delivered SGA neonates than in normal pregnant women (SGA, median 24.2 microg/l; range 11.9-788.7 vs. normal pregnancy, median: 14.4 microg/l; range 6.8-26.9; p = 0.001). Patients with pre-eclampsia had a higher median plasma TAT complex concentration than normal pregnant women (pre-eclampsia, median 18.1 microg/l; range 10.0-75.2 vs. normal pregnancy, median 14.4 microg/l; range 6.8-26.9; p = 0.02).

CONCLUSION

In vivo generation of thrombin, determined by the plasma concentrations of TAT complexes, is higher in patients with SGA fetuses and patients with pre-eclampsia than in normal pregnancy.

A role for the 72 kDa gelatinase (MMP-2) and its inhibitor (TIMP-2) in human parturition, premature rupture of membranes and intraamniotic infection

OBJECTIVE

Degradation of the extracellular matrix in fetal membranes has been implicated in the process of parturition and rupture of membranes. Matrix metalloproteinases (MMPs) are enzymes capable of degrading extracellular matrix including collagen. Tissue inhibitors of matrix metalloproteinases (TIMPs) inhibit the activity of MMPs by covalently binding to the enzymes. MMP-2 degrades Type IV collagen and TIMP-2 is its specific inhibitor. The objective of this study was to determine if human parturition, rupture of membranes (term and preterm) and microbial invasion of the amniotic cavity (MIAC) are associated with changes in the concentrations of MMP-2 and TIMP-2 in amniotic fluid.

STUDY DESIGN

A cross-sectional study was conducted with women in the following categories: 1) term with intact membranes, in labor and not in labor; 2) preterm labor and intact membranes who delivered at term, who delivered preterm and preterm labor with MIAC; 3) preterm premature rupture of membranes (PROM) with and without infection; 4) term and preterm PROM not in labor; and 5) midtrimester. MMP-2 and TIMP-2 concentrations in amniotic fluid were determined using sensitive and specific immunoassays.

RESULTS

The concentration of TIMP-2 increased with advancing gestational age (r = 0.6, p < 0.001). No correlation was found between MMP-2 concentrations and gestational age. Human parturition and rupture of membranes (term and preterm) and in patients with intact membranes were not associated with changes in the amniotic fluid MMP-2 concentrations. In contrast, 1) patients with spontaneous labor (term and preterm) had significantly lower median concentrations of TIMP-2 compared to those not in labor (p < 0.05 for both); 2) MIAC in women with preterm labor and preterm PROM was associated with a significant decrease in amniotic fluid TIMP-2 concentrations (p < 0.04 for both comparisons); 3) Rupture of the membranes (term and preterm) was also associated with a significant decrease in the amniotic fluid TIMP-2 concentrations (p < 0.05 and p < 0.03, respectively).

CONCLUSIONS

Human parturition (preterm and term), rupture of fetal membranes (term and preterm) and intraamniotic infection are associated with a significant decrease in amniotic fluid TIMP-2 concentrations.

Funisitis and chorionic vasculitis: the histological counterpart of the fetal inflammatory response syndrome

OBJECTIVE

To determine whether there is a relationship between the presence of histological signs of inflammation in the extraplacental membranes and umbilical cord and the concentrations of fetal plasma interleukin-6 (IL-6).

METHODS

The study examined a cohort of patients who were admitted with preterm labor or preterm premature rupture of the membranes (PROM) and who underwent cordocentesis. Inclusion criteria included fetal plasma available for IL-6 determination, histological examination of the umbilical cord and placenta, and delivery within 48 h of the procedure. This last criterion was used to preserve a meaningful temporal relationship between fetal plasma IL-6 and the results of histological examination of the placenta. Fetal plasma IL-6 was determined by a high sensitivity ELISA. Forty-five patients were available for study: 18 patients had preterm labor with intact membranes and 27 had preterm PROM.

RESULTS

The incidence of funisitis was 44.4% (20/45): 27.8% (5/18) in patients with preterm labor and intact membranes and 55.6% (15/27) in patients with preterm PROM. The median values of fetal plasma IL-6 in patients with funisitis, chorioamnionitis without funisitis, and non-inflamed membranes were 51.4, 18.4 and 5.2 pg/ml, respectively. After log transformation of the fetal plasma IL-6 concentration, the means differed significantly from each other (ANOVA, p < 0.02). There was no difference in log fetal plasma IL-6 concentration between patients with funisitis and those with chorioamnionitis without funisitis. The difference in mean concentration of log fetal plasma IL-6 between patients with funisitis or chorionic vasculitis and those without inflammation was highly significant (post-hoc test, p = 0.01 and p < 0.01, respectively). Fetuses with fetal plasma IL-6 > 11 pg/ml had a significantly higher rate of histological signs of inflammation in the extra-placental membranes and umbilical cord than those with fetal plasma IL-6 < 11 pg/ml (funisitis: 55.6% (15/27) vs. 27.8% (5/18), p < 0.05; chorionic vasculitis: 55.6% (15/27) vs. 12.5% (2/16), p < 0.01; chorioamnionitis only: 25.9% (7/27) vs. 16.7% (3/18), p < 0.05; no inflammation: 18.5% (5/27) vs. 55.6% (10/18), p < 0.05, respectively). Fetuses with funisitis had significantly higher rates of clinical and histological chorioamnionitis, and neonatal infectious morbidity (proven + suspected sepsis) than fetuses without funisitis (40% (8/20) vs. 8% (2/25), 90% (18/20) vs. 36% (9/25), and 40% (8/20) vs. 4% (1/25), respectively; p < 0.01 for each). Fetuses with chorionic vasculitis had significantly higher rates of clinical and histological chorioamnionitis as well as neonatal infectious morbidity (proven + suspected sepsis) than fetuses without chorionic vasculitis (100% (17/17) vs. 42.3% (11/26), p < 0.01; 82.4% (14/17) vs. 50.0% (13/26), p = 0.05; and 41.2% (7/17) vs. 7.7% (2/26), p = 0.01).

CONCLUSION

Fetal plasma IL-6 concentration is significantly associated with the presence of inflammatory lesions in the extraplacental membranes and umbilical cord. Fetuses with fetal plasma IL-6 > 11 pg/ml had a significantly higher rate of funisitis and/or chorionic vasculitis than fetuses with fetal plasma IL-6 < 11 pg/ml. These findings suggest that funisitis/chorionic vasculitis is the histological manifestation of the fetal inflammatory response syndrome.

The relationship between amniotic fluid matrix metalloproteinase-8 and funisitis

OBJECTIVE

The fetal inflammatory response syndrome is a multisystem disorder associated with impending preterm delivery and adverse neonatal outcome. Inflammation of the umbilical cord--funisitis--is the histologic counterpart of fetal inflammatory response syndrome and has been associated with an increased risk for the development of cerebral palsy. Neutrophils found in the amniotic cavity are of fetal origin. Therefore, neutrophil secretory products may be an index of the fetal inflammatory response syndrome. To test this hypothesis, we examined the relationship between levels of amniotic fluid matrix metalloproteinase-8 and funisitis.

STUDY DESIGN

The relationship between the presence of funisitis and concentrations of amniotic fluid matrix metalloproteinase-8 was examined in 255 consecutive patients who delivered preterm singleton neonates (gestational age, <36 weeks) within 72 hours of amniocentesis. Amniotic fluid was cultured for aerobic and anaerobic bacteria and for mycoplasmas. Funisitis was diagnosed in the presence of neutrophil infiltration into the umbilical vessel walls or Wharton jelly. Matrix metalloproteinase-8 was measured by use of a specific immunoassay. Nonparametric statistics were used for analysis.

RESULTS

Funisitis was present in 23% (59/255) of cases. Patients with funisitis had a significantly higher median concentration of amniotic fluid matrix metalloproteinase-8 than those without funisitis (median, 433.7 ng/mL [range, 1.5-3836.8 ng/mL] vs median, 1.9 ng/mL [range, <0.3-4202.7 ng/mL]; P <.001). The diagnostic indices of matrix metalloproteinase-8 (cutoff, 23 ng/mL) in the identification of funisitis were: sensitivity of 90% (53/59), specificity of 78% (153/196), positive predictive value of 55% (53/96), and negative predictive value of 96% (153/159).

CONCLUSIONS

There is a strong association between increased levels of amniotic fluid matrix metalloproteinase-8 and funisitis. We propose that determination of amniotic fluid matrix metalloproteinase-8 concentrations may assist the assessment of the fetal inflammatory status, thereby eliminating the need for fetal blood sampling.

Clinical significance of intra-amniotic inflammation in patients with preterm labor and intact membranes

OBJECTIVE

The purpose of this study was to determine the frequency and clinical significance of intraamniotic inflammation in patients with preterm labor and intact membranes.

STUDY DESIGN

Amniocentesis was performed in 206 patients with preterm labor and intact membranes. Amniotic fluid was cultured for aerobic and anaerobic bacteria and mycoplasmas. The diagnosis of intraamniotic inflammation was made in patients with a negative amniotic fluid culture on the basis of amniotic fluid concentrations of interleukin-6 (>2.6 ng/mL, derived from receiver operating characteristic curve analysis). Statistical analysis was conducted with contingency tables and survival techniques.

RESULTS

Intra-amniotic inflammation (negative amniotic fluid culture but elevated amniotic fluid interleukin-6) was more common than intra-amniotic infection (positive amniotic fluid culture regardless of amniotic fluid interleukin-6 concentration; 21% [44/206 women] vs 10% [21/206 women]; P <.001). The amniocentesisto-delivery interval was significantly shorter in patients with intra-amniotic inflammation than in patients with a negative culture and without an inflammation (median, 20 hours [range, 0.1-2328 hours] vs median, 701 hours [range, 0.1-3252 hours], respectively; P <.0001). Spontaneous preterm delivery of <37 weeks was more frequent in patients with intra-amniotic inflammation than in those with a negative culture and without inflammation (98% vs 35%; P <.001). Patients with intra-amniotic inflammation had a significantly higher rate of adverse outcome than patients with a negative culture and without intra-amniotic inflammation. Adverse outcomes included clinical and histologic chorioamnionitis, funisitis, early preterm birth, and significant neonatal morbidity. There were no significant differences in the rate of adverse outcomes between patients with a negative culture but with intra-amniotic inflammation and patients with intra-amniotic infection (positive culture regardless of amniotic fluid interleukin-6 concentration).

CONCLUSION

Intra-amniotic inflammation/infection complicates one third of the patients with preterm labor (32%; 65/206 women), and its presence is a risk factor for adverse outcome. The outcome of patients with microbiologically proven intra-amniotic infection is similar to that of patients with intra-amniotic inflammation and a negative amniotic fluid culture. We propose that the treatment of patients in preterm labor be based on the operational diagnosis of intra-amniotic inflammation rather than the diagnosis of intra-amniotic infection because the latter diagnosis cannot be undertaken rapidly.

Histo-topographic distribution of acute inflammation of the human umbilical cord

Acute inflammation of the umbilical cord, acute funisitis, is a sign of fetal inflammatory response, and the clinicopathological need for its identification is increasing. This study was conducted in order to describe the topographic distribution of acute funisitis, and thereby to provide more information on the intrinsic nature of acute funisitis and find a better way of pathologically examining the umbilical cord. A total of 10 umbilical cords affected by acute funisitis were histopathologically examined throughout their entire lengths at 1 mm intervals. Pathological examination was done to characterize the extent of the funisitis, the involvement of the vein (phlebitis) or of one or both arteries (arteritis), and the presence of inflammation in Wharton's jelly. Umbilical cord plasma interleukin (IL)-6 was measured by specific immunoassay to assess whether or not the severity of acute funisitis correlates with fetal cytokine response. It would appear that the inflammatory reaction begins as a discrete, multifocal process which eventually becomes contiguous as the inflammatory reaction proceeds. Umbilical cord plasma IL-6 concentrations tended to correlate with the extent of umbilical cord inflammation. The initial phase of acute funisitis involves discrete and multiple foci along the length of the umbilical cord. Moreover, the extent of acute funisitis reflects the severity of systemic fetal cytokine response. Therefore, adequate sampling using multiple sections would facilitate the identification of acute funisitis. We propose a standard sampling procedure taking one section from each third of the umbilical cord.

Phenotypic and metabolic characteristics of monocytes and granulocytes in normal pregnancy and maternal infection

OBJECTIVE

Normal pregnancy has been proposed to be a state of physiologic activation of the innate limb of the immune response. Recent studies have concluded that normal pregnancy produces inflammatory changes in peripheral blood leukocytes akin to those of sepsis. This unexpected observation has implications that are critical to understanding the susceptibility of pregnant women to sepsis, the pathophysiology of preeclampsia, and the biology of normal pregnancy. This study was designed to examine the phenotypic and metabolic characteristics of monocytes and granulocytes in normal pregnancy and in pregnant patients with acute infection.

STUDY DESIGN

A cross-sectional study was conducted that included nonpregnant women (n = 20), normal pregnant women (n = 57), and pregnant women with a positive blood culture and/or pyelonephritis (n = 16). Phenotypic and metabolic characteristics of monocytes and granulocytes were studied with the use of flow cytometry and monoclonal antibodies against surface markers (CD11b, CD14, CD15, CD16, CD18, CD49d, CD62L, CD64, CD66b, and HLA-DR). Intracellular reactive oxygen species were measured at basal conditions and after stimulation (oxidative burst). The stimulation index (ratio of intracellular reactive oxygen species after oxidative burst over basal state) was calculated. Nonparametric statistics were used. A probability value of <.01 was considered statistically significant.

RESULTS

Granulocytes from normal pregnant women had a higher median mean channel brightness for CD14 and CD64, but lower median mean channel brightness for CD16 and HLA-DR than granulocytes of nonpregnant women. Granulocytes of patients with acute infection had a higher median mean channel brightness for CD64 and CD66b than granulocytes of normal pregnant women. Monocytes from patients with acute infection had a higher mean channel brightness for CD11b, CD16, CD18, CD49d, CD64, and CD66b than monocytes of normal pregnant women. Baseline intracellular reactive oxygen species, oxidative burst, and stimulation index values were significantly higher in the granulocytes and monocytes of normal pregnant women than in the granulocytes and monocytes of nonpregnant women. Similarly, baseline intracellular reactive oxygen species, oxidative burst, and stimulation index values were higher in women with acute infections than in normal pregnant women.

CONCLUSION

Normal pregnancy was associated with phenotypic and metabolic changes of granulocytes and monocytes; pregnant women with acute infection had more marked phenotypic and metabolic changes of leukocytes than normal pregnant women. These qualitative differences indicate that the innate limb of the immune response is not maximally activated during normal pregnancy.

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

OBJECTIVE

Experimental and clinical studies support a role for the fetus in the control of the onset of labor. Fetal systemic inflammation, but not a maternal inflammatory response, has been linked to the onset of preterm labor and delivery on the basis of the determination of inflammatory cytokines in fetal and maternal blood. We propose that parturition requires fetomaternal cooperation and that inflammation is an integral part of the parturitional process. This study used flow cytometry, a sensitive technique for the detection of intravascular inflammation, to assess whether maternal inflammation is present in preterm labor.

STUDY DESIGN

A prospective cross-sectional study was performed including patients with preterm labor (n = 55) and women with normal pregnancy (n = 50). Intravascular inflammation was studied by using flow cytometry. Maternal blood was assayed to determine granulocyte and monocyte phenotype by using monoclonal antibodies, which included the following cluster of differentiation (CD) markers: CD11b, CD14, CD15, CD16, CD18, CD49d, CD62L, CD64, CD66b, and HLA-DR. Oxidative burst and generation of basal intracellular oxygen radical species were assessed. Statistical analysis was conducted with the use of nonparametric methods. A P value of <.01 was considered statistically significant.

RESULTS

Preterm labor was associated with a significant increase in the median mean channel brightness of CD11b, CD15, and CD66b on granulocytes and median mean channel brightness of CD11b and CD15 on monocytes. The ratio of oxidative burst over basal intracellular oxygen radical species in both granulocytes and monocytes was increased in preterm labor (P <. 01).

CONCLUSION

Preterm labor with intact membranes is associated with phenotypic and metabolic changes of maternal granulocytes and monocytes.

An elevated amniotic fluid matrix metalloproteinase-8 level at the time of mid-trimester genetic amniocentesis is a risk factor for spontaneous preterm delivery

OBJECTIVE

Strong evidence implicates chronic intra-amniotic inflammation in the etiology of mid-trimester abortion and spontaneous preterm delivery. The purpose of this study was to determine if concentrations of amniotic fluid matrix metalloproteinase-8, and cytokines such as interleukin-6 and angiogenin can identify patients at risk for spontaneous preterm delivery in patients undergoing mid-trimester amniocentesis.

STUDY DESIGN

A case-control study was conducted to compare mid-trimester concentrations of amniotic fluid matrix metalloproteinase-8, interleukin-6, and angiogenin in patients who delivered at term and in those who delivered before term. The study included 19 cases with spontaneous preterm delivery and 95 matched controls with normal outcomes. Patients with abnormal fetal karyotypes or major anomalies were excluded. Matrix metalloproteinase-8, interleukin-6, and angiogenin were measured by using specific immunoassays. Mann-Whitney U tests, Fisher exact tests, and receiver-operating characteristic curves were used for statistical analysis.

RESULTS

The median amniotic fluid matrix metalloproteinase-8, interleukin-6, and angiogenin concentrations of patients with spontaneous preterm delivery were significantly higher than those of control cases (matrix metalloproteinase-8: median, 3.1 ng/mL [range, 0.3-1954.9 ng/mL] vs median, 1.3 ng/mL [range, <0.3-45.2 ng/mL], P <.01; interleukin-6: median, 0.32 ng/mL [range, 0.04-2.52 ng/mL] vs median, 0.18 ng/mL [range, 0.01-1.81 ng/mL], P <.01; angiogenin: median, 11.1 ng/mL [range, 4.5-30.7 ng/mL] vs median, 6.7 ng/mL [range, 1.3-21.9 ng/mL], P <.001). Amniotic fluid matrix metalloproteinase-8 concentrations higher than 23 ng/mL had the highest specificity and odds ratio (sensitivity, 42% [8/19]; specificity, 99% [94/95]; OR, 68.4 [95% CI, 7.8-599.1]) in the identification of the patients with preterm delivery after genetic amniocentesis.

CONCLUSIONS

Elevated mid-trimester concentrations of amniotic fluid matrix metalloproteinase-8, interleukin-6, and angiogenin are a risk factor for early spontaneous preterm delivery (<32 weeks). An elevated matrix metalloproteinase-8 level of >23 ng/mL is a powerful predictor of spontaneous preterm delivery (<32 weeks) with an odds ratio of 68.4. Amniotic fluid studies can be used to improve the risk assessment for preterm delivery in women who undergo mid-trimester amniocentesis for genetic indications.

The frequency and clinical significance of intra-amniotic inflammation in patients with a positive cervical fetal fibronectin

OBJECTIVE

A positive fetal fibronectin result in cervicovaginal fluid is a powerful predictor of preterm delivery and is considered a marker for upper genital tract infection (ie, intrauterine infection). Treatment with antimicrobial agents is being considered in patients with a positive fetal fibronectin test of cervico/vaginal fluid. This study was undertaken to determine the frequency and clinical significance of intra-amniotic infection/inflammation in patients with a positive fetal fibronectin.

STUDY DESIGN

A total of 1709 pregnant women (gestational age, 23-31 weeks) were screened for cervical fetal fibronectin. Patients with a positive fibronectin were offered amniocentesis for the diagnosis of intra-amniotic infection and treatment with antibiotics. Amniocentesis was performed in 58 patients with a positive fibronectin test (>50 ng/mL). Amniotic fluid was cultured for aerobic/anaerobic bacteria and mycoplasmas. Polymerase chain reaction assay for Ureaplasma urealyticum was performed. Interleukin-6 concentrations were measured by a specific immunoassay. Nonparametric statistics were used for analysis.

RESULTS

None of the patients with a positive fibronectin had a positive amniotic fluid culture. U urealyticum was detected in 1 case (1.8%) with the polymerase chain reaction assay. Amniotic fluid IL-6 was elevated (>2.5 ng/mL) in 5.3% of patients (3/57 patients); all of these patients delivered preterm neonates. There was no relationship between amniotic fluid IL-6 and cervical fibronectin concentration (r = 0.14;P: >.1). Patients who delivered preterm (<34 weeks) had higher median amniotic fluid IL-6 and cervical fetal fibronectin concentrations than those patients who delivered after 34 weeks (IL-6: median, 2.1 ng/mL [range, 0.1-25.3 ng/mL] vs median, 0.3 ng/mL [0.03-2.4 ng/mL]; P <.05; fibronectin: median, 509 ng/mL [260->1000 ng/mL] vs median, 155 ng/mL [50-889 ng/mL]; P <.01).

CONCLUSION

Intra-amniotic infection was detected in 1.8% of cases with a positive fibronectin in the cervical fluid; intra-amniotic inflammation was present in 5.3% of cases. All patients with a positive fetal fibronectin and intra-amniotic inflammation delivered preterm neonates.

Phenotypic and metabolic characteristics of monocytes and granulocytes in preeclampsia

OBJECTIVE

The maternal syndrome of preeclampsia has recently been attributed to a systemic intravascular inflammatory response and endothelial cell activation and dysfunction. This novel hypothesis has considerable clinical and biological implications. This study was designed to determine whether women with preeclampsia have evidence of intravascular inflammation by examination of the phenotypic and metabolic activity of granulocytes and monocytes.

STUDY DESIGN

A cross-sectional study was performed that included patients with preeclampsia (n = 31) and normal pregnancies (n = 58) matched for gestational age at blood draw. Intravascular inflammation was studied with use of flow cytometry. Peripheral venous blood was assayed to determine granulocyte and monocyte phenotype with the use of monoclonal antibodies for selective cluster differentiation (CD) antigens. The panel of antibodies included CD11b, CD14, CD16, CD18, CD49d, CD62L, CD64, CD66b, and HLA-DR. The quantity of basal intracellular reactive oxygen species and oxidative burst was assessed. Results were reported as mean channel brightness or intensity of detected fluorescence. Analysis was conducted with nonparametric statistics. A P value <.01 was considered to be significant.

RESULTS

Preeclampsia was associated with a significant increase in mean channel brightness for CD11b on granulocytes and monocytes but lower mean channel brightness for CD62L on granulocytes than those from women with normal pregnancy (P <.01 for each). Basal intracellular reactive oxygen species were increased in monocytes but not in granulocytes. The oxidative burst was higher in both cell types.

CONCLUSION

Preeclampsia is associated with phenotypic and metabolic changes in granulocytes and monocytes.

Umbilical arteritis and phlebitis mark different stages of the fetal inflammatory response

OBJECTIVE

Funisitis, the inflammation of the umbilical cord determined by histologic examination of the placenta, is evidence of a fetal inflammatory response. The inflammatory process may involve the umbilical vein (phlebitis) and one or both umbilical arteries (arteritis) and extend into the Wharton's jelly. This study was conducted to examine whether the pattern of inflammation of the umbilical cord correlates with a biochemical marker of systemic fetal inflammation (umbilical cord plasma interleukin-6) and an adverse neonatal outcome.

STUDY DESIGN

This cohort study included 636 cases of preterm delivery (<36 weeks) with or without inflammation of the umbilical cord. Umbilical cord blood was collected at the time of delivery. The aim of pathologic examination was to characterize the extent of umbilical cord inflammation and the involvement of the vein (phlebitis), the involvement of one or both arteries (arteritis), and the presence of inflammation of the Wharton's jelly. Umbilical cord plasma interleukin-6 concentrations were assayed by a sensitive and specific immunoassay.

RESULTS

Neonates with umbilical arteritis had a significantly higher median concentration of cord plasma interleukin-6 (median, 111 pg/mL; range, 0.1-19,230 pg/mL) than those without umbilical arteritis (median, 22.5 pg/mL; range, 0.9-511.6 pg/mL; P <.05). Also, severe neonatal morbidity occurred more frequently in infants with arteritis than in those without arteritis (74% vs 50%; P <.05). And finally, the most severe form of inflammation, which involves both arteries, vein, and Wharton's jelly, was associated with the highest median concentration of plasma interleukin-6 observed in this study (median, 182.6 pg/mL; range, 0.1-7,400 pg/mL), whereas inflammation limited to the vein (phlebitis) was associated with a lower concentration of cord plasma interleukin-6 (median, 29.1 pg/mL; range, 0.9-511.6 pg/mL; P <.05).

CONCLUSION

Neonates whose placenta demonstrates umbilical arteritis have higher concentrations of umbilical cord plasma interleukin-6 and higher rates of adverse outcome than those without umbilical arteritis.

Acute funisitis of preterm but not term placentas is associated with severe fetal inflammatory response

Acute funisitis, whose basic pathologic feature is umbilical vasculitis, constitutes a type of fetal inflammatory response to intrauterine infection. In the present study, a comparative analysis was performed between the clinicopathologic profiles of acute funisitis in term and preterm placentas along with measurement of fetal plasma interleukin 6 (IL-6) levels by specific immunoassay to assess the different biologic implications for the fetus. Acute funisitis in preterm placentas showed a significantly higher incidence of umbilical arteritis (P <.000001), higher fetal plasma IL-6 level (P <.0001), and higher prevalence of major perinatal morbidities (P <.0001). To assess the possible variation in fetal cell response to infectious agents according to gestational age, amnion cells and placental villous tissues obtained at different gestational ages were treated with bacterial lipopolysaccharides, and the IL-6 level of the culture media was assayed. Amnion cells and placental villous tissues from preterm placenta showed a more pronounced cytokine response than those from term placenta. The findings of this study indicate that the clinicopathologic significance of acute funisitis in term placentas is different from that of preterm placentas. Furthermore, they indicate that the robust inflammatory response of the fetus associated with elevated fetal plasma IL-6 level may reflect the biologic needs of the premature fetus to escape from the hostile intrauterine environment.

The relationship between oligohydramnios and the onset of preterm labor in preterm premature rupture of membranes

OBJECTIVE

The objective of this study was to determine whether a reduced amniotic fluid volume was associated with the onset of preterm parturition in patients with preterm premature rupture of membranes.

STUDY DESIGN

An amniotic fluid index was determined before transabdominal amniocentesis in 129 patients with preterm premature rupture of membranes (gestational age < or = 35 weeks). Amniotic fluid was cultured for aerobic and anaerobic bacteria, as well as for mycoplasmas. Survival techniques were used for analysis.

RESULTS

Amniotic fluid index was < or = 5 cm in 29% of patients (38/129). Patients with an amniotic fluid index of < or = 5 cm had a significantly higher rate of positive amniotic fluid culture than those with an amniotic fluid index of >5 cm (42% [16/38] vs 18% [16/91]; P<.01). Spontaneous preterm delivery within 24 hours and 48 hours was more frequent among patients with an amniotic fluid index of < or = 5 cm than those with an amniotic fluid index of >5 cm (for 24 hours, 29% vs 12%; for 48 hours, 42% vs 21%; P<.05 for each). The amniocentesis-to-delivery interval was significantly shorter in patients with an amniotic fluid index of < or = 5 cm than in patients with an amniotic fluid index of >5 cm (median, 38 hours; range, 0.2-1310 hours; vs median, 100 hours; range 0.1-2917 hours; P<.01). Moreover, Cox proportional hazards model analysis indicated that an amniotic fluid index of < or = 5 cm was a significant predictor of the duration of the pregnancy after adjustment for gestational age and the results of amniotic fluid culture (odds ratio, 2.4; 95% confidence interval, 1.4-3.9; P<.001).

CONCLUSION

Patients with preterm premature rupture of membranes and an amniotic fluid index of < or = 5 cm are at increased risk for a shorter interval to delivery.

The relationship among inflammatory lesions of the umbilical cord (funisitis), umbilical cord plasma interleukin 6 concentration, amniotic fluid infection, and neonatal sepsis

OBJECTIVE

The purpose of this study was to determine whether funisitis (inflammation of the umbilical cord detected by histologic examination of the placenta) is associated with changes in the umbilical cord plasma concentration of interleukin 6, microbial invasion of the amniotic cavity, and neonatal sepsis.

STUDY DESIGN

The relationship among the presence of funisitis, interleukin 6 concentrations in umbilical cord plasma at birth, the results of amniotic fluid culture performed within 3 days of birth, and the occurrence of congenital neonatal sepsis was examined in 315 consecutive singleton preterm births (20-35 weeks' gestation). Funisitis was diagnosed in the presence of neutrophil infiltration into the umbilical vessel walls or Wharton jelly. The interleukin 6 concentration was measured with a specific immunoassay. Amniocentesis was performed in 106 patients within 3 days of birth. Amniotic fluid was cultured for aerobic and anaerobic bacteria and for mycoplasmas.

RESULTS

(1) Funisitis was present in 25% of patients (78/315). (2) Patients with funisitis had a significantly higher median cord plasma interleukin 6 and a lower gestational age at birth than did those without funisitis (cord interleukin 6: median, 52.4 pg/mL; range, 0.9-19,230 pg/mL; vs median, 4.6 pg/mL; range, 0-18,108 pg/mL; gestational age: median, 31.1 weeks' gestation; range, 21.0-35.0 weeks' gestation; vs median, 32.9 weeks' gestation; range, 21.4-35.0 weeks' gestation; P<.001 for each comparison). (3) A cord plasma interleukin 6 of > or =17.5 pg/mL had a sensitivity of 70% and a specificity of 78% in the identification of funisitis. (4) Microbial invasion of the amniotic cavity and clinical chorioamnionitis were more common among patients with funisitis than among those without funisitis (positive amniotic fluid culture: 53% [20/38]; vs. 12% [8/68]; clinical chorioamnionitis: 18% [14/78]; vs. 4% [9/237]; P<.001 for each comparison). (5) Neonates with funisitis had a significantly higher rate of congenital sepsis than did those without this lesion (12% [8/66] vs. 1% [3/216]; P<.001); this difference remained significant after adjustment for gestational age at birth (odds ratio, 7.2; 95% confidence interval, 1.8-29.0).

CONCLUSION

(1) Umbilical cord plasma interleukin 6 concentrations were higher in neonates born with funisitis than in those without this lesion. (2) Funisitis is associated with amniotic fluid infection, congenital neonatal sepsis, and the fetal inflammatory response syndrome.

Participation of the novel cytokine interleukin 18 in the host response to intra-amniotic infection

OBJECTIVE

Interleukin 18 is a proinflammatory pleiotropic cytokine that has been implicated in the host defense against infection. This study was undertaken to determine whether interleukin 18 concentrations change in the maternal, fetal, and amniotic fluid compartments with labor (term and preterm) and microbial invasion of the amniotic cavity.

STUDY DESIGN

Amniotic fluid was assayed for interleukin 18 in samples obtained from 285 patients in the following groups: (1) term not in labor (n = 22), in labor (n = 19), and with microbial invasion of the amniotic cavity (n = 16); (2) preterm labor who delivered at term (n = 38), who delivered preterm but without microbial invasion of the amniotic cavity (n = 41), and preterm labor with microbial invasion of the amniotic cavity (n = 24); (3) preterm premature rupture of membranes without microbial invasion of the amniotic cavity (n = 30) and with microbial invasion of the amniotic cavity (n = 34); (4) term premature rupture of membranes not in labor (n = 20) and term premature rupture of membranes in labor (n = 19); and (5) midtrimester (n = 22). In addition, cord and maternal plasma samples from women at term not in labor (n = 20) and in labor (n = 20) were assayed for interleukin 18.

RESULTS

(1) Interleukin 18 was detectable in all amniotic fluid samples and maternal and umbilical cord blood samples. (2) Interleukin 18 concentrations increased with advancing gestational age (r = 0.47; P <.0001). (3) Microbial invasion of the amniotic cavity in either preterm or term parturition was associated with a significant increase in the amniotic fluid concentration of interleukin 18 (preterm labor without microbial invasion of the amniotic cavity: median, 14.95 pg/mL; range, 3.9-277.0 pg/mL; vs preterm labor with microbial invasion of the amniotic cavity: median, 20.75 pg/mL; range, 5.53-160.21 pg/mL; P <.02; term labor without microbial invasion of the amniotic cavity: median, 18.73 pg/mL; range, 5.09-95.44 pg/mL; vs term labor with microbial invasion of the amniotic cavity: median, 24.35 pg/mL; range, 10.07-144.42 pg/mL; P<.004). (4) Both term and preterm parturition were associated with a modest increase in amniotic fluid interleukin 18 concentrations, although this trend did not reach statistical significance. (5) Rupture of membranes at term was associated with a significant decrease in amniotic fluid interleukin 18 concentrations (intact membranes: median, 14.96 pg/mL; range, <3.89-26.07 pg/mL; vs rupture of membranes: median, 10.1 pg/mL; range, 4.29-21.44 pg/mL; P <.001).

CONCLUSION

(1) Interleukin 18 is increased in cases of microbial invasion of the amniotic cavity. (2) Interleukin 18 is detectable in the amniotic, maternal, and fetal compartments. (3) We propose that this novel cytokine plays a role in the host defense against infection.

Further observations on the fetal inflammatory response syndrome: a potential homeostatic role for the soluble receptors of tumor necrosis factor alpha

OBJECTIVE

The fetal inflammatory response syndrome is a subclinical condition frequently present in preterm labor and preterm premature rupture of the membranes and is associated with increased perinatal morbidity and mortality. Tumor necrosis factor alpha is a mediator of septic shock and death, and it exerts its biologic effects by interacting with 2 receptors, TNF-R1 and TNF-R2. Soluble tumor necrosis factor receptors can buffer the biologic activity and protect against the deleterious effects of tumor necrosis factor alpha. The purpose of this study was to determine the behavior of soluble tumor necrosis factor receptors in fetuses with and without fetal inflammatory response syndrome.

STUDY DESIGN

Fetal blood sampling was performed in patients with preterm labor (n = 95) and preterm premature rupture of the membranes (n = 39). Control samples were obtained from fetuses who were undergoing blood sampling for clinical indications and had normal outcomes (n = 21). Fetal inflammatory response syndrome was defined as a fetal plasma interleukin 6 concentration >11 pg/mL. Concentrations of interleukin 6 and TNF-R1 and TNF-R2 were determined by use of sensitive and specific immunoassays. Analysis of covariance was used for statistical analysis.

RESULTS

(1) TNF-R1 and TNF-R2 were detectable in all samples, and their concentrations decreased with advancing gestational age (r = -0.8 and r = -0.7; P<.0001 and P<.001, respectively). (2) The mean fetal plasma concentrations of TNF-R1 and TNF-R2 were significantly higher in fetuses with fetal inflammatory response syndrome than in those without the syndrome after adjustment for gestational age and fetal membrane status (TNF-R1: no fetal inflammatory response syndrome, mean +/- SE, 3473.7+/-128.8 pg/mL; vs fetal inflammatory response syndrome, mean +/- SE, 4079.9+/-190.7 pg/mL; P<.005; TNF-R2: no fetal inflammatory response syndrome, mean +/- SE, 6033.2+/-235.4 pg/mL; vs. fetal inflammatory response syndrome, mean +/- SE, 7783.1+/-342.8 pg/mL; P<.0001). (3) Fetuses of patients who delivered within 72 hours of cordocentesis had significantly higher concentrations of TNF-R1 and TNF-R2 receptors than those with longer latency periods (P<.05 for each).

CONCLUSION

The fetal inflammatory response syndrome is associated with increased availability of the soluble receptors of tumor necrosis factor alpha in fetal plasma. These factors may attenuate the deleterious effects of tumor necrosis factor alpha.

Clinical implications of detection of Ureaplasma urealyticum in the amniotic cavity with the polymerase chain reaction

OBJECTIVE

The objective of this study was to determine the frequency and clinical significance of the detection of Ureaplasma urealyticum by means of the polymerase chain reaction with specific primers in the amniotic fluid of patients with preterm premature rupture of membranes.

STUDY DESIGN

Amniocentesis was performed in 154 patients with preterm premature rupture of membranes. Amniotic fluid was cultured for aerobic and anaerobic bacteria and for mycoplasmas. Ureaplasma urealyticum was detected by means of the polymerase chain reaction with specific primers. Patients were divided into the following 3 groups according to the results of amniotic fluid culture and polymerase chain reaction for U. urealyticum: those with a negative amniotic fluid culture and a negative polymerase chain reaction (n = 99), those with a negative amniotic fluid culture but a positive polymerase chain reaction (n = 18), and those with a positive amniotic fluid culture regardless of the results of the polymerase chain reaction (n = 37). Contingency table and survival techniques were used for analysis.

RESULTS

(1) U. urealyticum was detected by polymerase chain reaction in 28% (43/154) of patients and by culture in 16% (25/154). (2) Among the 43 patients with a positive polymerase chain reaction for U urealyticum, amniotic fluid culture was negative in 42% (18/43). (3) Patients with a negative amniotic fluid culture for U urealyticum but a positive polymerase chain reaction had a significantly shorter median interval from amniocentesis to delivery and a higher amniotic fluid interleukin 6 and white blood cell count than did those with a negative amniotic fluid culture and a negative polymerase chain reaction (interval to delivery; median, 53 hours; range, 0.3-335 hours; vs. median, 141 hours; range, 0.1-3552 hours; P<.05; amniotic fluid white blood cell count: median, 513 cells/mm(3); range, 1-2295 cells/mm(3); vs. median, 1 cell/mm(3); range, 0-7956 cells/mm(3); amniotic fluid interleukin 6: median, 16.6 ng/mL; range, 0.3-53.0 ng/mL; vs. median 0.4 ng/mL; range, 0-69.8 ng/mL; P<.0001 for all). (4) Patients with a positive polymerase chain reaction for U. urealyticum but a negative amniotic fluid culture had a higher rate of significant neonatal morbidity than did those with both a negative culture and a negative polymerase chain reaction (P<.05). (5) No significant differences in perinatal outcome were observed between patients with a negative culture but a positive polymerase chain reaction and those with a positive amniotic fluid culture.

CONCLUSION

(1) Culture techniques for mycoplasmas missed 40% of cases of microbial invasion of the amniotic cavity with U. urealyticum. (2) Patients with a positive polymerase chain reaction but a negative amniotic fluid culture are at risk for adverse outcomes. (3) The use of molecular microbiologic techniques is likely to increase the detection of infection among patients with obstetric complications.

Lactoferrin in intrauterine infection, human parturition, and rupture of fetal membranes

OBJECTIVE

Lactoferrin is an iron-binding protein with antimicrobial properties. This study was undertaken to determine whether amniotic fluid concentrations of this protein change with gestational age, infection, labor, and rupture of membranes.

STUDY DESIGN

This cross-sectional study included women who underwent transabdominal amniocentesis (n = 268) in the following groups: (1) mid trimester of pregnancy; (2) preterm labor who delivered at term, preterm labor who delivered preterm with intra-amniotic infection, and preterm labor who delivered preterm without intra-amniotic infection; (3) preterm premature rupture of membranes in the presence or absence of intra-amniotic infection; (4) term with intact membranes not in labor, in labor, and in labor with intra-amniotic infection; and (5) premature rupture of membranes at term not in labor. In addition, lactoferrin concentrations were determined in maternal plasma and cord blood of patients at term not in labor. Lactoferrin concentration was measured with an immunoassay.

RESULTS

(1) Lactoferrin was detectable in 85.4% (229/268) of amniotic fluid samples, not detectable in all fluid obtained in the mid trimester, and detectable in all maternal and cord plasma samples. (2) The concentration of lactoferrin increased with advancing gestational age (r = 0.68; P <.0001). (3) Intra-amniotic infection was associated with significant increases in amniotic fluid lactoferrin concentrations in patients with preterm labor (no intra-amniotic infection median, 1641.2 ng/mL; range, <1.24-35,090.0 ng/mL; vs intra-amniotic infection median, 3833.6 ng/mL; range, 746.0-47,020.0 ng/mL; P <.001), term labor (no intra-amniotic infection median, 2085.8 ng/mL; range, 425.0-23,230.0 ng/mL; vs intra-amniotic infection median, 5627.0 ng/mL; range, <1.24-19,220.0 ng/mL; P <. 001), and preterm premature rupture of membranes (no intra-amniotic infection median, 2190 ng/mL; range, <1.24-7456.1 ng/mL; vs intra-amniotic infection median, 3449.3 ng/mL; range, <1.24-83,600. 0; P <.01). (4) Spontaneous labor at term but not preterm was associated with a significant decrease in amniotic fluid lactoferrin concentration (P <.05). (5) Spontaneous term parturition was associated with a significant increase in umbilical cord plasma lactoferrin concentration (P <.005).

CONCLUSION

(1) Intra-amniotic infection was consistently associated with dramatically increased concentrations of lactoferrin in amniotic fluid. (2) Term parturition was associated with a significant increase in lactoferrin concentration in the fetal compartment (umbilical cord blood) and a decrease in the amniotic compartment. We propose that lactoferrin is part of the repertoire of host defense mechanisms against intra-amniotic infection.