X-linked inhibitor of apoptosis (XIAP) confers human trophoblast cell resistance to Fas-mediated apoptosis

Apoptosis occurs in the placenta throughout gestation, with a greater frequency near term in comparison to the first trimester. The Fas/FasL system represents one of the main apoptotic pathways controlling placental apoptosis. Although first trimester trophoblast cells express both Fas and FasL, they are resistant to Fas-induced apoptosis. Therefore, trophoblast resistance to Fas-mediated apoptosis may be due to the inhibition of the pathway downstream of Fas stimulation. Expression levels of X-linked inhibitor of apoptosis (XIAP) were recently shown to decrease in third trimester placentas, correlating with an increase in placental apoptosis. As a potent caspase inhibitor, XIAP prevents the activation of caspase-9 through its BIR3 domain and caspase-3 activation via the linker-BIR2 domain. In the present study, high levels of the active form of XIAP were detected in first trimester trophoblast cells, whereas term placental tissue samples predominantly expressed the inactive form of XIAP. Using a XIAP inhibitor, phenoxodiol, we demonstrate that XIAP inactivation sensitizes trophoblast cells to Fas stimulation, as evidenced by the anti-Fas mAb-induced decrease in trophoblast cell viability and increase in caspase-8, caspase-9 and caspase-3 activation. This suggests a functional role for XIAP in the regulation of the Fas apoptotic cascade in trophoblast cells during pregnancy.

The invasive phenotype of placenta accreta extravillous trophoblasts associates with loss of E-cadherin

INTRODUCTION

Epithelial-to-mesenchymal transition (EMT) is a process of molecular and phenotypic epithelial cell alteration promoting invasiveness. Loss of E-cadherin (E-CAD), a transmembrane protein involved in cell adhesion, is a marker of EMT. Proteolysis into N- and C-terminus fragments by ADAM10 and presenilin-1 (PSEN-1) generates soluble (sE-CAD) and transcriptionally active forms. We studied the protein expression patterns of E-CAD in the serum and placenta of women with histologically-confirmed over-invasive placentation.

METHODS

The patterns of expression and levels of sE-CAD were analyzed by Western blot, immunoassay, and immunoprecipitation. Tissue immunostaining for E-CAD, cytokeratin-7 (epithelial marker), vimentin (mesenchymal marker), ADAM10, PSEN-1 and β-catenin expression were investigated in parallel.

RESULTS

N-terminus cleaved 80 kDa sE-CAD fragments were present in serum of pregnant women with gestational age regulation of the circulatory levels. Women with advanced trophoblast invasion did not display circulatory levels of sE-CAD different from those of women with normal placentation. Histologically, extravillous trophoblasts (EVT) closer to the placental-myometrial interface demonstrated less E-CAD staining than those found deeper in the myometrium. These cells expressed both vimentin and cytokeratin, an additional feature of EMT. EVT of placentas with advanced invasion displayed intracellular E-CAD C-terminus immunoreactivity predominating over that of the extracellular N-terminus, a pattern consistent with preferential PSEN-1 processing.

DISCUSSION

Local processing of E-CAD may be an important molecular mechanism controlling the invasive phenotype of accreta EVT.

A comprehensive obstetric patient safety program reduces liability claims and payments

Begun in 2003, the Yale-New Haven Hospital comprehensive obstetric safety program consisted of measures to standardize care, improve teamwork and communication, and optimize oversight and quality review. Prior publications have demonstrated improvements in adverse outcomes and safety culture associated with this program. In this analysis, we aimed to assess the impact of this program on liability claims and payments at a single institution. We reviewed liability claims at a single, tertiary-care, teaching hospital for two 5-year periods (1998-2002 and 2003-2007), before and after implementing the safety program. Connecticut statute of limitations for professional malpractice is 36 months from injury. Claims/events were classified by event-year and payments were adjusted for inflation. We analyzed data for trends as well as differences between periods before and after implementation. Forty-four claims were filed during the 10-year study period. Annual cases per 1000 deliveries decreased significantly over the study period (P < .01). Claims (30 vs 14) and payments ($50.7 million vs $2.9 million) decreased in the 5-years after program inception. Compared with before program inception, median annual claims dropped from 1.31 to 0.64 (P = .02), and median annual payments per 1000 deliveries decreased from $1,141,638 to $63,470 (P < .01). Even estimating the monetary awards for the 2 remaining open cases using the median payments for the surrounding 5 years, a reduction in the median monetary amount per case resulting in payment to the claimant was also statistically significant ($632,262 vs $216,815, P = .046). In contrast, the Connecticut insurance market experienced a stable number of claims and markedly increased cost per claim during the same period. We conclude that an obstetric safety initiative can improve liability claims exposure and reduce liability payments.

Protein misfolding, congophilia, oligomerization, and defective amyloid processing in preeclampsia

Preeclampsia is a pregnancy-specific disorder of unknown etiology and a leading contributor to maternal and perinatal morbidity and mortality worldwide. Because there is no cure other than delivery, preeclampsia is the leading cause of iatrogenic preterm birth. We show that preeclampsia shares pathophysiologic features with recognized protein misfolding disorders. These features include urine congophilia (affinity for the amyloidophilic dye Congo red), affinity for conformational state–dependent antibodies, and dysregulation of prototype proteolytic enzymes involved in amyloid precursor protein (APP) processing. Assessment of global protein misfolding load in pregnancy based on urine congophilia (Congo red dot test) carries diagnostic and prognostic potential for preeclampsia. We used conformational state–dependent antibodies to demonstrate the presence of generic supramolecular assemblies (prefibrillar oligomers and annular protofibrils), which vary in quantitative and qualitative representation with preeclampsia severity. In the first attempt to characterize the preeclampsia misfoldome, we report that the urine congophilic material includes proteoforms of ceruloplasmin, immunoglobulin free light chains, SERPINA1, albumin, interferon-inducible protein 6-16, and Alzheimer’s β-amyloid. The human placenta abundantly expresses APP along with prototype APP-processing enzymes, of which the α-secretase ADAM10, the β-secretases BACE1 and BACE2, and the γ-secretase presenilin-1 were all up-regulated in preeclampsia. The presence of β-amyloid aggregates in placentas of women with preeclampsia and fetal growth restriction further supports the notion that this condition should join the growing list of protein conformational disorders. If these aggregates play a pathophysiologic role, our findings may lead to treatment for preeclampsia.

Improving maternal health and safety through adherence to postpartum hemorrhage protocol in Latin America

OBJECTIVE

To determine provider compliance with protocols for the prevention of postpartum hemorrhage and provider characteristics associated with adherence and non-adherence.

METHODS

A multicenter descriptive study was conducted involving 78 direct observations of provider-implemented protocols and 52 interviews with Peruvian maternal healthcare providers at 4 Peruvian clinical sites representing the local, regional, and national levels of care. Parturient participants planning a normal vaginal delivery were 17-49 years of age and 34-42 weeks pregnant. Primary outcomes were compared using χ2 testing, while quantitative survey data were evaluated using means, standard deviations, and Student t test or analysis of variance for statistical significance.

RESULTS

There were 3 significant differences between the national, regional, and local levels of care: adherence to all 3 interventions (P<0.001); professional experience (P<0.04); and retention of healthcare providers (P<0.001). There were no differences in provider training (P<0.097), and the retention of experienced healthcare providers was not associated with greater adherence to protocols. There were no significant differences in parturient characteristics.

CONCLUSION

Individual characteristics and institutional beliefs may have more influence than experience or training on adherence to protocols for prevention of postpartum hemorrhage; addressing these biases may improve patient safety in Peru and throughout Latin America.

Comparative analysis of 2-D versus 3-D ultrasound estimation of the fetal adrenal gland volume and prediction of preterm birth

OBJECTIVE

We aim to test the hypothesis that two-dimensional (2-D) fetal adrenal gland volume (AGV) measurements offer similar volume estimates as volume calculations based on 3-D technique.

METHODS

Fetal AGV was estimated by three-dimensional (3-D) ultrasound (VOCAL) in 93 women with signs/symptoms of preterm labor and 73 controls. Fetal AGV was calculated using an ellipsoid formula derived from 2-D measurements of the same blocks (0.523 × length × width × depth). Comparisons were performed by intraclass correlation coefficient (ICC), coefficient of repeatability, and Bland-Altman method. The corrected AGV (cAGV; AGV/fetal weight) was calculated for both methods and compared for prediction of preterm birth (PTB) within 7 days.

RESULTS

Among 168 volumes, there was a significant correlation between 3-D and 2-D methods (ICC = 0.979; 95% confidence interval [CI]: 0.971 to 0.984). The coefficient of repeatability for the 3-D was superior to the 2-D method (intraobserver 3-D: 30.8, 2-D:57.6; interobserver 3-D:12.2, 2-D: 15.6). Based on 2-D calculations, cAGV ≥ 433 mm3/kg was best for prediction of PTB (sensitivity: 75%, 95% CI = 59 to 87; specificity: 89%, 95% CI = 82 to 94). Sensitivity and specificity for the 3-D cAGV (cutoff ≥ 420 mm3/kg) was 85% (95% CI = 70 to 94) and 95% (95% CI = 90 to 98), respectively. In receiver-operating-curve curve analysis, 3-D cAGV was superior to 2-D cAGV for prediction of PTB (z = 1.99, p = 0.047).

CONCLUSION

2-D volume estimation of fetal adrenal gland using ellipsoid formula cannot replace 3-D AGV calculations for prediction of PTB.

Antenatal lamivudine to reduce perinatal hepatitis B transmission: a cost-effectiveness analysis

OBJECTIVES

This study aimed to determine whether administration of lamivudine to pregnant women with chronic hepatitis B in the third trimester is a cost-effective strategy in preventing perinatal transmission.

STUDY DESIGN

We developed a decision analysis model to compare the cost-effectiveness of 2 management strategies for chronic hepatitis B in pregnancy: (1) expectant management or (2) lamivudine administration in the third trimester. We assumed that lamivudine reduced perinatal transmission by 62%.

RESULTS

Our Markov model demonstrated that lamivudine administration is the dominant strategy. For every 1000 infected pregnant women treated with lamivudine, $337,000 is saved and 314 quality-adjusted life-years are gained. For every 1000 pregnancies with maternal hepatitis B, lamivudine prevents 21 cases of hepatocellular carcinoma and 5 liver transplants in the offspring. The model remained robust in sensitivity analysis.

CONCLUSION

Antenatal lamivudine administration to pregnant patients with hepatitis B is cost-effective, and frequently cost-saving, under a wide range of circumstances.

Prenatal hazardous substance use and adverse birth outcomes

OBJECTIVE

Assess the relative effects of a variety of illicit and licit drugs on risk for adverse birth outcomes.

METHODS

We used data from two large prospective investigations, and a novel analytic method, recursive partitioning class analysis to identify risk factors associated with preterm birth and delivering a small for gestational age infant.

RESULTS

Compared to cocaine and opiate non-users, cocaine users were 3.53 times as likely (95% CI: 1.65-7.56; p = 0.001) and opiate users 2.86 times as likely (95% CI: 1.11-7.36; p = 0.03) to deliver preterm. The odds of delivering a small for gestational age infant for women who smoked more than two cigarettes daily was 3.74, (95% CI: 2.47-5.65; p<0.0001) compared to women who smoked two or less cigarettes daily and had one previous child. Similarly, less educated, nulliparous women who smoked two or fewer cigarettes daily were 4.12 times as likely (95% CI: 2.04-8.34; p < 0.0001) to have a small for gestational age infant.

CONCLUSIONS

Among our covariates, prenatal cocaine and opiate use are the predominant risk factors for preterm birth; while tobacco use was the primary risk factor predicting small for gestational age at delivery. Multi-substance use did not substantially increase risk of adverse birth outcomes over these risk factors.

Screening for gestational diabetes mellitus: are the criteria proposed by the international association of the Diabetes and Pregnancy Study Groups cost-effective?

OBJECTIVE

The International Association of the Diabetes and Pregnancy Study Groups (IADPSG) recently recommended new criteria for diagnosing gestational diabetes mellitus (GDM). This study was undertaken to determine whether adopting the IADPSG criteria would be cost-effective, compared with the current standard of care.

RESEARCH DESIGN AND METHODS

We developed a decision analysis model comparing the cost-utility of three strategies to identify GDM: 1) no screening, 2) current screening practice (1-h 50-g glucose challenge test between 24 and 28 weeks followed by 3-h 100-g glucose tolerance test when indicated), or 3) screening practice proposed by the IADPSG. Assumptions included that 1) women diagnosed with GDM received additional prenatal monitoring, mitigating the risks of preeclampsia, shoulder dystocia, and birth injury; and 2) GDM women had opportunity for intensive postdelivery counseling and behavior modification to reduce future diabetes risks. The primary outcome measure was the incremental cost-effectiveness ratio (ICER).

RESULTS

Our model demonstrates that the IADPSG recommendations are cost-effective only when postdelivery care reduces diabetes incidence. For every 100,000 women screened, 6,178 quality-adjusted life-years (QALYs) are gained, at a cost of $125,633,826. The ICER for the IADPSG strategy compared with the current standard was $20,336 per QALY gained. When postdelivery care was not accomplished, the IADPSG strategy was no longer cost-effective. These results were robust in sensitivity analyses.

CONCLUSIONS

The IADPSG recommendation for glucose screening in pregnancy is cost-effective. The model is most sensitive to the likelihood of preventing future diabetes in patients identified with GDM using postdelivery counseling and intervention.

Indications contributing to the increasing cesarean delivery rate

OBJECTIVE

To examine physician-documented indications for cesarean delivery in order to investigate the specific factors contributing to the increasing cesarean delivery rate.

METHODS

We analyzed rates of primary and repeat cesarean delivery, including indications for the procedure, among 32,443 live births at a major academic hospital between 2003 and 2009. Time trends for each indication were modeled to estimate the absolute and cumulative annualized relative risk of cesarean by indication over time and the relative contribution of each indication to the overall increase in primary cesarean delivery rate.

RESULTS

The cesarean delivery rate increased from 26% to 36.5% between 2003 and 2009; 50.0% of the increase was attributable to an increase in primary cesarean delivery. Among the documented indications, nonreassuring fetal status, arrest of dilation, multiple gestation, preeclampsia, suspected macrosomia, and maternal request increased over time, whereas arrest of descent, malpresentation, maternal-fetal indications, and other obstetric indications (eg, cord prolapse, placenta previa) did not increase. The relative contributions of each indication to the total increase in primary cesarean rate were: nonreassuring fetal status (32%), labor arrest disorders (18%), multiple gestation (16%), suspected macrosomia (10%), preeclampsia (10%), maternal request (8%), maternal-fetal conditions (5%), and other obstetric conditions (1%).

CONCLUSION

Primary cesarean births accounted for 50% of the increasing cesarean rate. Among primary cesarean deliveries, more subjective indications (nonreassuring fetal status and arrest of dilation) contributed larger proportions than more objective indications (malpresentation, maternal-fetal, and obstetric conditions).

Universal cervical-length screening to prevent preterm birth: a cost-effectiveness analysis

OBJECTIVE

To determine whether routine measurement of second-trimester transvaginal cervical length by ultrasound in low-risk singleton pregnancies is a cost-effective strategy.

METHODS

We developed a decision analysis model to compare the cost-effectiveness of two strategies for identifying pregnancies at risk for preterm birth: (1) no routine cervical length screening and (2) a single routine transvaginal cervical length measurement at 18-24 weeks' gestation. In our model, women identified as being at increased risk (cervical length < 1.5 cm) for preterm birth would be offered daily vaginal progesterone supplementation. We assumed that vaginal progesterone reduces preterm birth at < 34 weeks' gestation by 45%. We also assumed that a decreased cervical length could result in additional costs (ultrasound scans, inpatient admission) without significantly improved neonatal outcomes. The main outcome measure was incremental cost-effectiveness ratio.

RESULTS

Our model predicts that routine cervical-length screening is a dominant strategy when compared to routine care. For every 100,000 women screened, $12,119,947 can be potentially saved (in 2010 US dollars) and 423.9 quality-adjusted life-years could be gained. Additionally, we estimate that 22 cases of neonatal death or long-term neurologic deficits could be prevented per 100,000 women screened. Screening remained cost-effective but was no longer the dominant strategy when cervical-length ultrasound measurement costs exceeded $187 or when vaginal progesterone reduced delivery risk at < 34 weeks by less than 20%.

CONCLUSION

In low-risk pregnancies, universal transvaginal cervical length ultrasound screening appears to be a cost-effective strategy under a wide range of clinical circumstances (varied preterm birth rates, predictive values of a shortened cervix and costs).

Accreta complicating complete placenta previa is characterized by reduced systemic levels of vascular endothelial growth factor and by epithelial-to-mesenchymal transition of the invasive trophoblast

OBJECTIVE

We sought to characterize serum angiogenic factor profile of women with complete placenta previa and determine if invasive trophoblast differentiation characteristic of accreta, increta, or percreta shares features of epithelial-to-mesenchymal transition.

STUDY DESIGN

We analyzed gestational age-matched serum samples from 90 pregnant women with either complete placenta previa (n = 45) or uncomplicated pregnancies (n = 45). Vascular endothelial growth factor (VEGF), placental growth factor, and soluble form of fms-like-tyrosine-kinase-1 were immunoassayed. VEGF and phosphotyrosine immunoreactivity was surveyed in histological specimens relative to expression of vimentin and cytokeratin-7.

RESULTS

Women with previa and invasive placentation (accreta, n = 5; increta, n = 6; percreta, n = 2) had lower systemic VEGF (invasive previa: median 0.8 [0.02-3.4] vs control 6.5 [2.7-10.5] pg/mL, P = .02). VEGF and phosphotyrosine immunostaining predominated in the invasive extravillous trophoblasts that coexpressed vimentin and cytokeratin-7, an epithelial-to-mesenchymal transition feature and tumorlike cell phenotype.

CONCLUSION

Lower systemic free VEGF and a switch of the interstitial extravillous trophoblasts to a metastable cell phenotype characterize placenta previa with excessive myometrial invasion.

Ultrasound measurement of fetal adrenal gland enlargement: an accurate predictor of preterm birth

OBJECTIVE

The objective of the study was to test whether ultrasound-measured fetal adrenal gland volume (AGV) and fetal zone enlargement (FZE) predicts preterm birth (PTB) better than cervical length (CL).

STUDY DESIGN

Three-dimensional and 2-dimensional ultrasound were used prospectively to measure fetal AGV, FZE, and CL in women with preterm labor symptoms. We corrected AGV for fetal weight (cAGV). The ratio between whole gland depth (D) and central fetal zone depth (d) (d/D) was used to measure FZE. Ability of cAGV, d/D, and CL to predict PTB 7 days or less was compared.

RESULTS

Twenty-seven of 74 women (36.5%) presenting between 21 and 34 weeks had PTB of 7 days or less. FZE greater than 49.5% was the single best predictor for PTB (sensitivity/specificity 100%/89%) compared with cAGV (81%/87%) and CL (56%/60%; P < .05). Prediction was independent of obstetrics history and tocolytic use.

CONCLUSION

The 2-dimensional measurement of the adrenal gland FZE is highly effective performing superior to CL in identifying women at risk for PTB within 7 days.

A comprehensive obstetrics patient safety program improves safety climate and culture

OBJECTIVE

The purpose of this study was to determine the effect of an obstetrics patient safety program on staff safety culture.

STUDY DESIGN

We implemented (1) obstetrics patient safety nurse, (2) protocol-based standardization of practice, (3) crew resource management training, (4) oversight by a patient safety committee, (5) 24-hour obstetrics hospitalist, and (6) an anonymous event reporting system. We administered the Safety Attitude Questionnaire on 4 occasions over 5 years (2004-2009) to all staff members that assessed teamwork and safety cultures, job satisfaction, working conditions, stress recognition, and perceptions of management.

RESULTS

We observed significant improvements in the proportion of staff members with favorable perceptions of teamwork culture (39% in 2004 to 63% in 2009), safety culture (33% to 63%), job satisfaction (39% to 53%), and management (10% to 37%). Individual roles (obstetrics providers, residents, and nurses) also experienced improvements in safety and teamwork, with significantly better congruence between doctors and nurses.

CONCLUSION

Safety programs can improve workforce perceptions of safety and an improved safety climate.

Interpretation of 2002 Centers for Disease Control guidelines for group B streptococcus and evolving provider practice patterns

We investigated if clinicians were altering their care of group B streptococcus (GBS)-positive women in labor to achieve 4 hours of intrapartum antibiotic prophylaxis based on their interpretation of the 2002 Centers for Disease Control (CDC) guidelines on prevention of perinatal GBS disease. We surveyed all clinicians with privileges on the labor floor at our institution about their interpretation and clinical application of the 2002 CDC guidelines. Seventy of 96 eligible clinicians (72.9%) completed our survey. In our survey, only 22.9% of clinicians reported not altering their management of labor in GBS-positive pregnancies that achieved less than 4 hours of prophylaxis. These alterations included "laboring down" or delaying pushing; turning off or decrease an oxytocin infusion; or delaying or avoiding artificial rupture of membranes. Clinicians are altering their management of labor to attempt to achieve 4 hours of intrapartum prophylaxis. The 2002 CDC guidelines do not specifically recommend prolonging labor and are being interpreted differently in the clinical setting than the authors may have intended. The effects and consequences of this interpretation are unknown.

IL-6 trans-signaling system in intra-amniotic inflammation, preterm birth, and preterm premature rupture of the membranes

Classic IL-6 signaling is conditioned by the transmembrane receptor (IL-6R) and homodimerization of gp130. During trans-signaling, IL-6 binds to soluble IL-6R (sIL-6R), enabling activation of cells expressing solely gp130. Soluble gp130 (sgp130) selectively inhibits IL-6 trans-signaling. To characterize amniotic fluid (AF) IL-6 trans-signaling molecules (IL-6, sIL-6R, sgp130) in normal gestations and pregnancies complicated by intra-amniotic inflammation (IAI), we studied 301 women during second trimester (n = 39), third trimester (n = 40), and preterm labor with intact (n = 131, 85 negative IAI and 46 positive IAI) or preterm premature rupture of membranes (PPROM; n = 91, 61 negative IAI and 30 positive IAI). ELISA, Western blotting, and real-time RT-PCR were used to investigate AF, placenta, and amniochorion for protein and mRNA expression of sIL-6R, sgp130, IL-6R, and gp130. Tissues were immunostained for IL-6R, gp130, CD15(+) (polymorphonuclear), and CD3(+) (T cell) inflammatory cells. The ability of sIL-6R and sgp130 to modulate basal and LPS-stimulated release of amniochorion matrix metalloprotease-9 was tested ex vivo. We showed that in physiologic gestations, AF sgp130 decreases toward term. AF IL-6 and sIL-6R were increased in IAI, whereas sgp130 was decreased in PPROM. Our results suggested that fetal membranes are the probable source of AF sIL-6R and sgp130. Immunohistochemistry and RT-PCR revealed increased IL-6R and decreased gp130 expression in amniochorion of women with IAI. Ex vivo, sIL-6R and LPS augmented amniochorion matrix metalloprotease-9 release, whereas sgp130 opposed this effect. We conclude that IL-6 trans-signaling molecules are physiologic constituents of the AF regulated by gestational age and inflammation. PPROM likely involves functional loss of sgp130.

Normative postpartum intraabdominal pressure: potential implications in the diagnosis of abdominal compartment syndrome

OBJECTIVE

We sought to establish normative values of intraabdominal pressure (IAP) in postpartum women with and without arterial hypertension.

STUDY DESIGN

Bladder pressure was measured via a Foley catheter 1 hour following completion of cesarean section in supine and semirecumbent positions in 21 patients.

RESULTS

Mean supine IAP (6.4 +/- 5.2 mm Hg) was significantly lower than semirecumbent IAP (11.6 +/- 7.2 mm Hg) (P < .05). Body mass index (BMI) was significantly correlated to IAP regardless of the gestational age (r(2) supine = 0.46, semirecumbent = 0.37; P = .004 for either). Increasing gravidity was associated with decreasing IAP. Patients with arterial hypertension had higher BMI, were delivered earlier, and had higher IAP than patients with normal arterial pressure, either in supine or semirecumbent position. However, these relationships were not significant when results were controlled for BMI.

CONCLUSION

Postcesarean section IAP is higher than in the general surgical population. Patients with hypertensive disorders have IAPs approaching to intraabdominal hypertension range.

Amniotic fluid angiopoietin-1, angiopoietin-2, and soluble receptor tunica interna endothelial cell kinase-2 levels and regulation in normal pregnancy and intraamniotic inflammation-induced preterm birth

BACKGROUND

Angiopoietin-1 (Ang-1) and Ang-2 act selectively on endothelial cells by engaging the Tunica interna endothelial cell kinase-2 (Tie2) receptor. A soluble form of Tie2 (sTie2) blocks angiopoietin bioactivity.

OBJECTIVE

The aim of the study was to characterize changes and expression patterns of Ang-1, Ang-2, and sTie2 in amniotic fluid (AF) and placenta during human pregnancy and intraamniotic inflammation (IAI)-induced preterm birth.

DESIGN AND SETTING

We conducted a cross-sectional study at a tertiary university hospital.

PATIENTS

AF levels of Ang-1, Ang-2, and sTie2 were evaluated in 176 women during second trimester (n = 40), third trimester (n = 37), and preterm labor (positive IAI, n = 50; negative IAI, n = 49). Placenta and cord blood of select women were analyzed.

MAIN OUTCOME MEASURES

Ang-1, Ang-2, sTie2, and IL-6 were evaluated by ELISA. Real-time PCR measured Ang-1, Ang-2, and Tie2 placental mRNA levels. Placenta was immunostained for Ang-1 and Ang-2. Placental explant cultures were stimulated with lipopolysaccharide, Pam3Cys, and modulators of protein synthesis/secretion (cycloheximide, monensin, and brefeldin A).

RESULTS

In normal pregnancy, the levels and ratios of AF Ang-1, Ang-2, and sTie2 varied with gestational age (GA) (P < 0.001). PCR revealed corresponding changes in placental Ang-1 and Ang-2, but not Tie2, mRNA. IAI raised AF Ang-1, Ang-2, and sTie2 above the expected level for GA without affecting their placental mRNA. Ang-2 immunoreactivity appeared enhanced in areas of villous edema. AF Ang-2/Ang-1 ratio was an important determinant of cord blood IL-6 (P < 0.001). Ex-vivo, sTie2 release was increased by Golgi disrupting but not bacterial mimic agents.

CONCLUSIONS

Ang-1, Ang-2, and sTie2 are physiological constituents of AF that are GA and IAI regulated. Ang-2/Ang-1 ratio may play a role in modulating the fetal inflammatory response to IAI. Placental sTie2 shedding likely involves a Golgi-mediated mechanism.

Human labor is associated with reduced decidual cell expression of progesterone, but not glucocorticoid, receptors

CONTEXT

Unchanging plasma progesterone (P4) levels suggest that human labor is initiated by reduced P4 receptor (PR) expression, which elicits functional P4 withdrawal. The glucocorticoid receptor (GR) is also implicated in this process.

OBJECTIVE

Our objective was to compare PR and GR staining in human decidual cells (DCs) and interstitial trophoblasts (ITs) of gestational age-matched pre- and postcontraction specimens and to evaluate steroid effects on PR and GR expression in human DC cultures.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Decidua basalis and parietalis sections were immunostained for PR or GR and then for the cytoplasmic DC and IT markers vimentin and cytokeratin. Western blotting measured PR and GR levels in nuclear extracts of cultured leukocyte-free term DCs after incubation with estradiol-17beta (E2) with or without medroxyprogesterone acetate (MPA).

RESULTS

PR histological scores (HSCOREs) were significantly higher in DC nuclei from pre- vs. post-uterine-contraction decidua basalis and parietalis sections with PR immunostaining absent from ITs. In contrast, immunoreactive GR was localized in IT and DC nuclei. GR HSCORES were significantly higher in ITs than DCs but similar in pre- vs. post-uterine-contraction specimens. In term DC monolayers, PR-A and PR-B were enhanced by E2 and inhibited by MPA, whereas E2 plus MPA produced intermediate PR expression. The GR was constitutively expressed.

CONCLUSIONS

In post- vs. pre-uterine-contraction specimens, significantly lower HSCOREs in DC nuclei, but not IT, and unchanging GR levels in DCs and ITs suggest that functional P4 withdrawal may occur in DCs and is unlikely to involve the GR. Nuclear extracts from DC monolayer cultures express steroid-regulated PR-A and PR-B and constitutive GR.

Determination of placental weight using two-dimensional sonography and volumetric mathematic modeling

An abnormally decreased placental weight has been linked to increased perinatal complications, including intrauterine fetal demise (IUFD) and fetal growth restriction (IUGR). Despite its promise, determining placental weight prenatally using three-dimensional systems is time-consuming and requires expensive technology and expertise. We propose a novel method using two-dimensional sonography that provides an immediate estimation of placental volume. Placental volume was calculated in 29 third-trimester pregnancies using linear measurements of placental width, height, and thickness to calculate the convex-concave shell volume within 24 hours of birth. Data were analyzed to calculate Spearman's rho (r (s)) and significance. There was a significant correlation between estimated placental volume (EPV) and actual placental weight (r (s) = 0.80, P < 0.001). Subgroup analysis of preterm gestations ( N = 14) revealed an even more significant correlation of EPV to actual placental weight (r (s) = 0.89, P < 0.001). Placental weight can be accurately predicted by two-dimensional ultrasound with volumetric calculations. This method is simple, rapid, and accurate, making it practical for routine prenatal care, as well as for high-risk cases with decreased fetal movement and IUGR. Routine EPV surveillance may decrease the rates of perinatal complications and unexpected IUFD.

The role of urinary soluble endoglin in the diagnosis of pre-eclampsia: comparison with soluble fms-like tyrosine kinase 1 to placental growth factor ratio

OBJECTIVE

Endoglin, an anti-angiogenic glycoprotein expressed on endothelial cells, has been proposed recently as a biomarker of pre-eclampsia (PE). Given that PE is characterised by an imbalance of angiogenic factors, we sought to determine the clinical utility of urinary soluble endoglin, relative to the soluble fms-like tyrosine kinase 1 to placental growth factor (PlGF) ratio, in the diagnosis of PE during gestation.

DESIGN

Prospective observational cohort.

SETTING

Tertiary referral university hospital.

POPULATION

Two hundred and thirty-four pregnant women were enrolled prospectively in the following groups: healthy controls, n = 63; gestational age (GA), median (interquartile range), 33 weeks (27-39 weeks); chronic hypertension, n = 27; GA, 33 weeks (30-36 weeks); mild PE, n = 38; GA, 37 weeks (34-40 weeks); severe PE, n = 106; GA, 32 weeks (29-37 weeks).

METHODS

Free urinary levels of soluble endoglin, soluble fms-like tyrosine kinase 1 and PlGF were measured by sensitive and specific immunoassay. Levels for all urinary analytes were normalised to creatinine.

MAIN OUTCOME MEASURES

Urinary soluble endoglin, and the soluble fms-like tyrosine kinase 1 to PlGF ratio.

RESULTS

In healthy controls, urinary soluble endoglin levels were increased significantly at term relative to those earlier in gestation. Severe PE was characterised by an increased urinary level of soluble endoglin, soluble fms-like tyrosine kinase 1, protein to creatinine ratio and soluble fms-like tyrosine kinase 1 to PlGF ratio compared with all other groups. There was a direct correlation between urinary soluble endoglin and proteinuria that remained after GA correction (R = 0.382, P < 0.001). Urinary soluble endoglin could not differentiate mild PE from severe preterm PE. Overall, soluble endoglin had the ability to discriminate PE from chronic hypertension and healthy controls only in women who were evaluated at <37 weeks of GA. The sensitivity, specificity and accuracy of urinary soluble endoglin alone in the diagnosis of PE or in the identification of women with PE requiring a mandated delivery before 37 weeks of gestation were 70%, 86% and 76%, respectively. These values were inferior to those of the soluble fms-like tyrosine kinase 1 to PlGF ratio (P < 0.001). The addition of urinary soluble endoglin did not improve the diagnostic accuracy of the soluble fms-like tyrosine kinase 1 to PlGF ratio alone.

CONCLUSIONS

We have provided evidence that soluble endoglin is present and elevated in the urine of women who develop preterm PE. Urinary soluble endoglin has only limited ability to determine the severity of PE and to distinguish between PE and chronic hypertension both preterm and at term. Compared with urinary soluble endoglin, the soluble fms-like tyrosine kinase 1 to PlGF ratio remains a better marker of disease presence, severity and outcome.

Disparities in cesarean delivery rates and associated adverse neonatal outcomes in New York City hospitals

OBJECTIVE

To examine the primary cesarean delivery rates and associated neonatal outcomes by insurance status in public and private hospitals in New York City.

METHODS

We accessed Vital statistics data on all births to women with Medicaid or private insurance from 1996 through 2003, compiling a total of 321,308 nulliparous women who delivered singleton neonates by either normal spontaneous vaginal delivery or primary cesarean delivery. Rates of primary cesarean delivery and adverse neonatal outcomes were examined by hospital type and insurance status while controlling for potential confounders.

RESULTS

There were 51,682 and 269,626 women who delivered in public hospitals and private hospitals, respectively. The cesarean delivery rate of women with private insurance delivering in private hospitals was 30.4% compared with a cesarean rate of 21.2% in Medicaid patients delivering in public hospitals (adjusted odds ratio [OR] 1.57, 95% confidence interval [CI] 1.53-1.63). The percent of infants born to women with private insurance and Medicaid delivering in private hospitals with a 5-minute Apgar score less than 7 was 0.6% and 0.8% compared with 1.0% of infants delivering in the public hospital system (adjusted OR 0.59, 95% CI 0.51- 0.68 and adjusted OR 0.73, 95% CI 0.65- 0.82). The neonatal intensive care unit admission rate was also lower in neonates born in private hospitals at 6.7% and 8.5% compared with a 12.8% admission rate in public hospitals (adjusted OR 0.48, 95% CI 0.46-0.51 and adjusted OR 0.59, 95% CI 0.57- 0.62 after controlling for mode of delivery).

CONCLUSION

Even when controlling for confounders, there was an association between primary cesarean delivery and insurance status regardless of hospital type. There was also a higher risk of adverse neonatal outcomes in the public hospitals regardless of mode of delivery.

LEVEL OF EVIDENCE

III.

Progestin and thrombin regulate tissue factor expression in human term decidual cells

CONTEXT

Perivascular cell membrane-bound tissue factor (TF) initiates hemostasis via thrombin generation. The identity and potential regulation of TF-expressing cells at the human maternal-fetal interface that confers hemostatic protection during normal and preterm delivery is unclear.

OBJECTIVES

The objective of the study were to identify TF-expressing cells at the maternal-fetal interface in term and preterm decidual sections by immunohistochemistry and evaluate progestin, thrombin, TNF-alpha, and IL-1beta effects on TF expression by cultured human term decidual cells (DCs).

INTERVENTIONS AND MAIN OUTCOME MEASURES

Serial placental sections were immunostained for TF. Leukocyte-free term DC monolayers were incubated with 10(-8) M estradiol (E2) or E2 plus 10(-7) M medroxyprogestrone acetate (MPA) +/- thrombin or TNF-alpha or IL-1beta. ELISA and Western blotting assessed TF in cell lysates. Quantitative real-time RT-PCR measured TF mRNA levels.

RESULTS

Immunolocalized TF in DC membranes in preterm and term placental sections displayed higher Histologic Scores than villous mesenchymal cells (P < 0.05). TF was undetected in interstitial or extravillous trophoblasts. Compared with DCs incubated with E2, MPA and 2.5 U/ml thrombin each doubled TF levels (P < 0.05) and E2 + MPA + thrombin further doubled TF levels (P < 0.05), whereas TNF-alpha and IL-1beta were ineffective. Western blotting confirmed the ELISA results. Quantitative RT-PCR revealed corresponding changes in TF mRNA levels.

CONCLUSIONS

In human term placental sections, DC-expressed TF exceeds that of other cell types at the maternal-fetal interface and is localized at the cell membranes in which it can bind to factor VII and meet the hemostatic demands of labor and delivery via thrombin formation. Unlike the general concept that TF is constitutive in cells that highly express it, MPA and thrombin significantly enhanced TF expression in term DC monolayers.

Hypertensive pregnancy disorders and subsequent cardiovascular morbidity and type 2 diabetes mellitus in the mother

Minimal data exist concerning the relationship between hypertensive pregnancy disorders and various subsequent cardiovascular events and the effect of type 2 diabetes mellitus on these. In a registry-based cohort study, we identified women delivering in Denmark from 1978 to 2007 with a first singleton (n=782 287) and 2 first consecutive singleton deliveries (n=536 419). The exposures were gestational hypertension and mild and severe preeclampsia. We adjusted for preterm delivery, small for gestational age, placental abruption, and stillbirth and, in a second model, we also adjusted for the development of type 2 diabetes mellitus. The end points were subsequent hypertension, ischemic heart disease, congestive heart failure, thromboembolic event, stroke, and type 2 diabetes mellitus. The risk of subsequent hypertension was increased 5.31-fold (range: 4.90 to 5.75) after gestational hypertension, 3.61-fold (range: 3.43 to 3.80) after mild preeclampsia, and 6.07-fold (range: 5.45 to 6.77) after severe preeclampsia. The risk of subsequent type 2 diabetes mellitus was increased 3.12-fold (range: 2.63 to 3.70) after gestational hypertension and 3.68-fold (range: 3.04 to 4.46) after severe preeclampsia. Women having 2 pregnancies both complicated by preeclampsia had a 6.00-fold (range: 5.40 to 6.67) increased risk of subsequent hypertension compared with 2.70-fold (range: 2.51 to 2.90) for women having preeclampsia in their first pregnancy only and 4.34-fold (range: 3.98 to 4.74) for women having preeclampsia in their second pregnancy only. The risk of subsequent thromboembolism was 1.03-fold (range: 0.73 to 1.45), 1.53-fold (range: 1.32 to 1.77), and 1.91-fold (range: 1.35 to 2.70) increased after gestational hypertension and mild and severe preeclampsia, respectively. Thus, hypertensive pregnancy disorders are strongly associated with subsequent type 2 diabetes mellitus and hypertension, the latter independent of subsequent type 2 diabetes mellitus. The severity, parity, and recurrence of these hypertensive pregnancy disorders increase the risk of subsequent cardiovascular events.

The cost-effectiveness of universal screening in pregnancy for subclinical hypothyroidism

OBJECTIVE

The purpose of this study was to determine whether routine screening for subclinical hypothyroidism during pregnancy would be cost-effective.

STUDY DESIGN

We developed a decision analysis model to compare the cost-effectiveness of 2 screening strategies during pregnancy for subclinical hypothyroidism: (1) no routine screening of serum thyroid-stimulating hormone (TSH) levels (standard) and (2) routine screening of TSH levels. In the latter, women with subclinical hypothyroidism received thyroid hormone replacement. We assumed that thyroid hormone replacement could reduce the incidence of an offspring IQ < 85 for pregnancies with subclinical hypothyroidism. The main outcome measure was marginal cost per quality-adjusted life year (QALY) gained.

RESULTS

Our model predicts that universal screening is the dominant strategy. For every 100,000 pregnant women who were screened, $8,356,383 are saved, and 589.3 QALYs are gained. When subclinical hypothyroidism prevalence is reduced to 0.25%, screening remains cost-effective at $21,664/QALY gained.

CONCLUSION

Screening for subclinical hypothyroidism in pregnancy will be a cost-effective strategy under a wide range of circumstances.

Timing of fetal meconium absorption by amnionic macrophages

This study sought to determine the time interval from fetal defecation to membrane staining and subsequent meconium uptake by amnionic macrophages. Pieces of external membranes were fastened to Teflon rings to create a well. The amnionic surface was exposed to meconium and amniotic fluid for 1 to 48 hours and analyzed microscopically for the presence of free meconium and meconium-laden amnionic macrophages. In each of the experiments, prior to the 12-hour time point, few meconium-laden macrophages were present in the membrane layers. A significant rise in the number of meconium-laden macrophages and a concomitant increase in staining intensity was noted in the membranes at 24 and 48 hours. Contrary to previous reports, our in vitro model of meconium incorporation into placental membranes demonstrated that significant numbers of meconium-laden macrophages were only observed after 24 and 48 hours.

Proteomic profiling of urine identifies specific fragments of SERPINA1 and albumin as biomarkers of preeclampsia

OBJECTIVE

The cause of preeclampsia remains unknown and the diagnosis can be uncertain. We used proteomic-based analysis of urine to improve disease classification and extend the pathophysiologic understanding of preeclampsia.

STUDY DESIGN

Urine samples from 284 women were analyzed by surface-enhanced laser desorption/ionization. In the exploratory phase, 59 samples were used to extract the proteomic fingerprint characteristic of severe preeclampsia requiring mandated delivery and to develop a diagnostic algorithm. In the challenge phase, we sought to prospectively validate the algorithm in 225 women screened for a variety of high- and low-risk conditions, including preeclampsia. Of these, 19 women were followed longitudinally throughout pregnancy. The presence of biomarkers was interpreted relative to clinical classification, need for delivery, and other urine laboratory measures (ratios of protein to creatinine and soluble fms-like tyrosine kinase-1 to placental growth factor). In the translational phase, biomarker identification by tandem mass spectrometry and validation experiments in urine, serum, and placenta were used to identify, quantify, and localize the biomarkers or related proteins.

RESULTS

We report that women with preeclampsia appear to present a unique urine proteomic fingerprint that predicts preeclampsia in need of mandated delivery with highest accuracy. This characteristic proteomic profile also has the ability to distinguish preeclampsia from other hypertensive or proteinuric disorders in pregnancy. Pregnant women followed longitudinally who developed preeclampsia displayed abnormal urinary profiles more than 10 weeks before clinical manifestation. Tandem mass spectrometry and de novo sequencing identified the biomarkers as nonrandom cleavage products of SERPINA1 and albumin. Of these, the 21 amino acid C-terminus fragment of SERPINA1 was highly associated with severe forms of preeclampsia requiring early delivery. In preeclampsia, increased and aberrant SERPINA1 immunoreactivity was found in urine, serum, and placenta, in which it localized predominantly to placental villi and placental vascular spaces adherent to the endothelium. In addition, significant perivascular deposits of misfolded SERPINA1 aggregates were exclusively identified in preeclamptic placentae.

CONCLUSION

Proteomics-based characterization of urine in preeclampsia identified a proteomic fingerprint composed of SERPINA1 and albumin fragments, which can accurately diagnose preeclampsia and shows promise to discriminate it from other hypertensive proteinuric diseases. These findings provide insight into a novel pathophysiological mechanism of preeclampsia related to SERPINA1 misfolding, which may offer new therapeutic opportunities in the future.

Stillbirth at term in women of advanced maternal age in the United States: when could the antenatal testing be initiated?

We sought to determine if advanced maternal age (AMA) is a risk factor for intrauterine fetal demise (IUFD). We used a U.S. Centers for Disease Control and Prevention database and analyzed outcomes in women 15 to 44 years of age with term singleton gestations. Cox proportional hazards models and Cochran-Mantel-Haenszel tests were used. Results were controlled for maternal race and smoking. After excluding congenital anomalies and medical complications, 6,239,399 singleton term deliveries were identified. When compared with women 25 to 29 years of age, the risk of IUFD increased with advancing age: 30 to 34 years, odds ratio [OR] = 1.24 (95% confidence interval [CI], 1.13 to 1.36); 35 to 39 years, OR = 1.45 (95% CI, 1.21 to 1.74), and 40 to 44 years, OR = 3.04 (95% CI, 1.58 to 5.86). The risk of IUFD for women 40 to 44 years of age at 39 weeks is comparable with that of 42 weeks in those 25 to 29 years of age. We concluded that AMA is an independent predictor of IUFD, and a strategy of antenatal testing in those > or = 40 years of age beginning at 38 weeks may be considered.

Matrix metalloproteinase 9 (MMP9) expression in preeclamptic decidua and MMP9 induction by tumor necrosis factor alpha and interleukin 1 beta in human first trimester decidual cells

Extravillous trophoblasts (EVTs) invade human decidua via sequential integrin-mediated binding and proteolysis of basement membrane proteins in the extracellular matrix (ECM). In preeclampsia, shallow EVT invasion impairs spiral artery and arteriole remodeling to reduce uteroplacental blood flow. Excess decidual cell-expressed matrix metalloproteinases (MMPs) 2 and 9, in response to preeclampsia-related interleukin 1 beta (IL1B) and tumor necrosis factor alpha (TNF), may inappropriately degrade these basement membrane proteins and impede EVT invasion. This study found significantly higher immunohistochemical MMP9 levels in decidual cells and adjacent interstitial trophoblasts in placental sections of preeclamptic versus gestational age-matched control women. In contrast, immunostaining for MMP2 and tissue inhibitor of matrix metalloproteinases 1 and 2 (TIMP1 and TIMP2) were similar in preeclamptic and control groups. First-trimester decidual cells were incubated with estradiol (E(2)) or E(2) + medroxyprogesterone acetate (MPA), with or without TNF or IL1B. As measured by ELISA, both cytokines elicited concentration-dependent increases in secreted MMP9 levels that were unaffected by MPA. In contrast, secreted levels of MMP2, TIMP1, and TIMP2 were unchanged in all treatment groups. Substrate gel zymography and Western blotting confirmed that each cytokine increased secreted levels of MMP9 but not MMP2. Similarly, quantitative RT-PCR found that TNF and IL1B enhanced MMP9, but not MMP2, mRNA levels. At the implantation site, inflammatory cytokine-enhanced MMP9 may promote preeclampsia by disrupting the decidual ECM to interfere with normal stepwise EVT invasion.

Prepregnancy body mass index, hypertensive disorders of pregnancy, and long-term maternal mortality

OBJECTIVE

Recent studies have shown increased maternal mortality rates after hypertensive disorders of pregnancy (HDP), but the reasons for this increase remain unclear. This study examines the relationship between elevated prepregnancy body mass index (BMI), HDP, and postpregnancy mortality.

STUDY DESIGN

Data came from a 1975-1976 subset (n = 13,722 women) of a population-based cohort. Multiple logistic regression was used to examine the risk of HDP by BMI; age-adjusted Cox proportional hazards models were used to examine survival rates.

RESULTS

Overweight (BMI, 25-29.9 kg/m2) and obesity (BMI, > or = 30 kg/m2) were associated with increased HDP (odds ratio [OR], 2.82; 95% confidence interval [CI], 2.40-3.31 and OR, 5.51; 95% CI, 4.15-7.31]) and decreased survival (hazard ratio [HR], 1.42; 95% CI, 1.10-1.83 and HR, 2.43; 95% CI, 1.61-3.68), compared with normal weight (BMI, 18.5-24.9 kg/m2). HDP was significantly associated with increased mortality rates for women who survived > 15 years (HR, 1.94; 95% CI, 1.42-2.67]; HR adjusted for BMI, 1.65; 95% CI, 1.19-2.79]). A greater increase in risk of death after HDP was seen in the overweight women (HR, 1.86; 95% CI, 1.07-3.20) and obese women (HR, 2.90; 95% CI, 1.28-6.58), compared with normal weight women (HR, 1.26; 95% CI, 0.74-2.14).

CONCLUSION

Elevated prepregnancy BMI is associated with increased risk of HDP, which are in turn is associated with increased long-term maternal mortality rates. This association between HDP and mortality rates increases with elevated prepregnancy BMI.

Thrombin regulates soluble fms-like tyrosine kinase-1 (sFlt-1) expression in first trimester decidua: implications for preeclampsia

The primary placental defect in preeclampsia is shallow trophoblast invasion of the decidua leading to incomplete vascular transformation and inadequate uteroplacental perfusion. Soluble fms-like tyrosine kinase-1 (sFlt-1) seems to interfere with these events by inhibiting local angiogenesis and/or by impeding trophoblast invasion. Preeclampsia is also associated with maternal thrombophilias and decidual hemorrhage, which form thrombin from decidual cell-expressed tissue factor. Although sFlt-1 is highly expressed by trophoblasts, sFlt-1 expression has not been studied in decidual cells, which are the predominant cell type encountered by invading trophoblasts. Here, we demonstrate that isolated decidual cells express sFlt-1 mRNA, suggesting that they can synthesize sFlt-1. Moreover, in first trimester decidual cells, thrombin enhanced sFlt-1 mRNA levels, as measured by quantitative reverse transcriptase-polymerase chain reaction, and levels of secreted sFlt-1 protein, as measured by enzyme-linked immunosorbent assay. The thrombin antagonist hirudin blocked this effect, demonstrating that active thrombin is required. Emphasizing the specificity of the thrombin response, neither interleukin-1beta nor tumor necrosis factor-alpha affected sFlt-1 expression in the decidual cells. In contrast to first trimester decidual cells, thrombin did not affect sFlt-1 levels in cultured term decidual cells. In early pregnancy, thrombin may act as an autocrine/paracrine enhancer of sFlt-1 expression by decidual cells to promote pre-eclampsia by interfering with local vascular transformation.

Fetal Adrenal Gland Volume

OBJECTIVE

To investigate the risk of preterm birth (delivery at less than 37 weeks of gestation) by evaluating the fetal adrenal gland volume, hallmark of activation of the fetal hypothalamic-pituitary-adrenal axis, measured by 3-dimensional ultrasonography.

METHODS

We performed 3-dimensional ultrasound examination of the fetal adrenal gland volume in 126 singleton fetuses, prospectively comparing those born to mothers with signs or symptoms of preterm labor (n=53) to control subjects (n=73). Multiplanar technique with rotational methods for measurement of fetal adrenal gland volume was performed by using Virtual Organ Computer-Aided Analysis (VOCAL) technology.

RESULTS

The fetal adrenal gland volume was successfully examined in 86.5% of the cases. There was a direct relationship between the fetal adrenal gland volume and estimated fetal weight. A corrected adrenal gland volume of greater than 422 mm3/kg was best in predicting preterm birth within 5 days from the time of the measurement. The sensitivity, specificity, and positive and negative likelihood ratios were 92%, 99%, 93.5, and 0.08, respectively. Multiple logistic regression analysis showed that the corrected adrenal gland volume was the only significant independent predictor factor of preterm birth within 5 days of measurement.

CONCLUSION

Corrected adrenal gland volume measurement may identify women at risk for impending preterm birth. This information can be generated noninvasively and in time for clinical decision making.

LEVEL OF EVIDENCE

II.

Progestin inhibits and thrombin stimulates the plasminogen activator/inhibitor system in term decidual stromal cells: implications for parturition

OBJECTIVE

Labor is associated with 'decidual activation' with increased proteolysis and extracellular matrix degradation. The balance between plasminogen activator inhibitor-1 (PAI-1) and urokinase (uPA) and tissue-type plasminogen activator (tPA) is an important determinant of proteolytic activity at the maternal-fetal interface. Thrombin released at the time of placental abruption (decidual hemorrhage) is known to promote decidual proteolysis and uterine contractions. This study investigates the separate and interactive effects of steroid hormones and thrombin on PAI-1, uPA, and tPA expression by term decidual cells (DCs).

STUDY DESIGN

Term DCs were isolated by enzymatic digestion, purified, and depleted of leukocytes. Cells were treated with estradiol (10(-8) mol [E2]), medroxyprogesterone acetate (10(-7) mol [MPA]), both, or vehicle for 7 days. After 24-hour incubation with or without thrombin (0.1-2.5 U/mL), levels of PAI-1, uPA, and tPA in conditioned supernatant were measured by specific ELISA and Western blotting. Levels of PAI-1 and uPA mRNA were measured by quantitative RT-PCR.

RESULTS

In the cultured term DCs, ELISA measurements indicated that basal output of PAI-1 was about 2 logs higher than that of either uPA or tPA (2.5 +/- 0.7 ng/mL per microg protein, 13.4 +/- 6.3 pg/mL per microg protein, and 25.4 +/- 10.8 pg/mL per microg protein, respectively). Although E2 alone did not affect PAI-1 output, MPA and E2+MPA significantly enhanced PAI-1 production (2.5 +/- 0.7 vs 8.2 +/- 2.0 ng/mL per microg protein for E2+MPA [3.3-fold]; P < .01). By contrast, uPA output was inhibited by exposure to MPA (13.4 +/- 6.3 vs 2.6 +/- 1.1 pg/mL per microg protein [0.2-fold]; P < .05), whereas tPA production was not affected by MPA. Thrombin did not significantly affect uPA and tPA production by term DCs. In contrast, in E2+MPA-treated term DCs, thrombin, a hemostatic proinflammatory cytokine, selectively increased PAI-1 output in a dose-dependent fashion, which could be blocked by the selective thrombin inhibitor, hirudin. Western blotting confirmed the effects of MPA and thrombin in elevating secreted levels of PAI-1. Unlike the increase in PAI-1 output elicited by thrombin, term DCs were unresponsive to either of the classic proinflammatory cytokines, TNFalpha or IL-1beta. Corresponding effects on PAI-1 mRNA levels were elicited by MPA and thrombin as seen for PAI-1 protein expression, suggesting that these up-regulatory effects are transcriptionally mediated.

CONCLUSION

Progestin enhanced PAI-1 and inhibited uPA expression by term DCs, which may explain in part the pregnancy-prolonging properties of progesterone as a consequence of inhibited proteolytic activity at the maternal-fetal interface. Thrombin augmented PAI-1 expression in the absence of increased uPA or tPA expression by term DCs, suggesting that abruption-associated decidual proteolysis and preterm labor is mediated primarily by thrombin-enhanced matrix metalloproteinase expression rather than an indirect effect on the plasminogen activator/inhibitor system.