1,25(OH)2D3 suppresses COX-2 up-regulation and thromboxane production in placental trophoblast cells in response to hypoxic stimulation.

In this study, we determined if vitamin D could inhibit oxidative stress-induced thromboxane production by placental trophoblasts. Trophoblast isolated from normal placentas were stimulated with CoCl2, a hypoxic mimicking agent, with or without pretreatment of 1,25(OH)2D3. Soluble phospholipase-A2, metabolites of thromboxane-A2 and prostacyclin, and 8-isoprostane were measured. Expression of cyclooxygenase-1 (COX-1), COX-2, and heme oxygenase-1 (HO-1) were determined. We found that pretreatment of trophoblasts with 1,25(OH)2D3 significantly reduced 8-isoprostane and the ratio of thromboxane-A2 to prostacyclin production, and blocked COX-2 expression induced by CoCl2. These results provide evidence of the beneficial effects of vitamin D on placental trophoblasts.

PAR-2 triggers placenta-derived protease-induced altered VE-cadherin reorganization at endothelial junctions in preeclampsia.

PAR-2 is a G-protein coupled protease receptor whose activation in endothelial cells (ECs) is associated with increased solute permeability. VE-cadherin is an endothelial-specific junction protein, which exhibits a disorganized distribution at cell junction during inflammation and is a useful indicator of endothelial barrier dysfunction. In the present study, we tested the hypothesis that PAR-2 activation mediates placenta-derived chymotrypsin-like protease (CLP)-induced endothelial junction disturbance and permeability in preeclampsia (PE). PAR-2 and VE-cadherin were examined by immunofluorescent staining. Specific CLP induced PAR-2 activation and altered VE-cadherin distribution was assessed following depletion of protease chymotrypsin in the placental conditioned medium and after PAR-2 siRNA. VE-cadherin assembly was determined by treating cells with protease chymotrypsin and/or the specific PAR-2 agonist SLIGKV-NH2. Our results showed: 1) placental conditioned medium not only disturbed VE-cadherin distribution at cell junctions but also activated PAR-2 in ECs; 2) PAR-2 siRNA blocked the placental conditioned medium induced PAR-2 upregulation and disorganization of VE-cadherin at cell junctions; 3) PAR-2 agonist induced PAR-2 activation and VE-cadherin reorganization were dose-dependent; and 4) PAR-2 agonist could stimulate ERK1/2 activation. These results strongly suggest that proteases produced by the placenta elicit endothelial barrier dysfunction via a PAR-2 signaling regulatory mechanism in PE.

ADAM17 regulates TNFα production by placental trophoblasts.

Increased trophoblast TNFα production is an important component of placental dysfunction in preeclampsia. However, the mechanism of increased TNFα production in the preeclamptic placenta is largely unknown. ADAM17 is a metallopeptidase that functions as a TNFα converting enzyme. In this study, we examined ADAM17 expression in placentas from normal and preeclamptic pregnancies and found increased ADAM17 expression in preeclamptic placentas compared to those from normal placentas, p < 0.05. Since hypoxia/oxidative stress is an underlying pathophysiology in the preeclamptic placenta, we further determined if hypoxia/oxidative stress could modulate ADAM17 expression and subsequently induce TNFα production in placental trophoblasts. Trophoblasts were isolated from normal term placentas and treated with cobalt (II) chloride (CoCl(2)), a hypoxia mimetic agent, at different concentrations. Our results showed that CoCl(2) induced a dose-dependent increase in TNFα production that is associated with enhanced ADAM17 expression. Trophoblast expressions of HO-1 (a sensor of cellular oxidative stress) and caspase-3 (an indicator of apoptosis) in response to CoCl(2) stimulation were also examined. We further found that metallopeptidase inhibitor GM6001 and ADAM17 siRNA could block CoCl(2) induced TNFα production, demonstrating the role of ADAM17 in TNFα production in placental trophoblasts. These results suggest that oxidative stress-induced increased ADAM17 expression could contribute to the increased TNFα production in preeclamptic placentas.

D2-40/podoplanin expression in the human placenta.

Placental tissue expresses many lymphatic markers. The current study was undertaken to examine if D2-40/podoplanin, a lymphatic endothelial marker, was expressed in the human placenta, and how it is altered developmentally and pathologically. We examined D2-40/podoplanin and VEGFR-3 expressions in placentas from normotensive pregnancies at different gestational ages and in placentas from women with clinically defined preeclampsia. D2-40 expression in systemic lymphatic vessel endothelium served as a positive control. Protein expression for D2-40, VEGFR-3, and ß-actin was determined by Western blot in placentas from normotensive (n = 6) and preeclamptic (n = 5) pregnancies. Our results show that D2-40/podoplanin was strongly expressed in the placenta, mainly as a network plexus pattern in the villous stroma throughout gestation. CD31 was limited to villous core fetal vessel endothelium and VEGFR-3 was found in both villous core fetal vessel endothelium and trophoblasts. D2-40/podoplanin expression was significantly decreased, and VEGFR-3 significantly increased in preeclamptic placental tissues compared to normotensive placental controls. Placental villous stroma is a reticular-like structure, and the localization of D2-40 to the stroma suggests that a lymphatic-like conductive network may exist in the human placenta. D2-40/podoplanin is an O-linked sialoglycoprotein. Although little is known regarding biological functions of sialylated glycoproteins within the placenta, placental D2-40/podoplanin may support fetal vessel angiogenesis during placenta development and reduced D2-40/podoplanin expression in preeclamptic placenta may contribute to altered interstitial fluid homeostasis and impaired angiogenesis in this pregnancy disorder.

Proteases and sFlt-1 release in the human placenta.

Increased placental release of soluble VEGF receptor-1 (sFlt-1) is believed to play an important role in the pathogenesis of preeclampsia (PE). Although the reason for increased placental sFlt-1 release in PE is unknown, proteolytic effect has been proposed as one of the mechanisms that mediate sFlt-1 release in the placenta. In this study, using various protease inhibitors, we tested the possible role of proteases in sFlt-1 release by human placenta. Villous explants from normal term placentas were incubated with various protease inhibitors including serine protease inhibitors (PMSF, aprotini, and specific chymotrypsin inhibitor (CI)), cysteine protease inhibitor E-64, metalloendopeptidase inhibitor PAD, and universal metalloprotease (ADAM) inhibitor PTM. Culture medium was collected and measured for sFlt-1 by ELISA. Our results showed that villous tissue treated with CI and PTM produced significantly less sFlt-1 than those of controls. PMSF, aprotini, E-64, and PAD had no effect on sFlt-1 release. We further examined chymotrypsin-like protease/chymase and ADAM10 expressions in tissue sections from normal and PE placentas by immunohistochemistry. We found that immunostaining for chymase and ADAM10 was significantly increased in the layer of syncytiotrophoblasts in PE placentas compared to normal placentas. These results suggest chymotrypsin-like serine protease and ADAM10, but not cysteine protease and metalloendopeptidase, may play a role in inducing sFlt-1 release in PE placentas.

Temporal pattern and spectral complexity as stimulus parameters for eliciting a cardiac orienting reflex in human fetuses.

The purpose of this study was to determine whether temporal pattern and/or spectral complexity were important stimulus parameters for eliciting a cardiac orienting reflex (OR) in low-risk human fetuses. Each of 28 term fetuses was exposed to four sounds formed from the four different combinations of temporal pattern (pulsed, continuous) and spectral complexity (sine wave, /â/). The fetal cardiac electrical signal was captured transabdominally at a rate of 1024 Hz, and fetal R-waves were extracted by using adaptive signal-processing techniques. We found that pulsed sounds elicited a significantly greater decrease in heart rate (HR) than did continuous sounds. However, the HR response was relatively unaffected by spectral complexity. For the pure tone and the phoneme used in this study, our results indicate that temporal characteristics were more effective at eliciting a cardiac OR in human fetuses than was spectral complexity.

Human fetuses have nonlinear cardiac dynamics.

Approximate entropy (ApEn) is a statistic that quantifies regularity in time series data, and this parameter has several features that make it attractive for analyzing physiological systems. In this study, ApEn was used to detect nonlinearities in the heart rate (HR) patterns of 12 low-risk human fetuses between 38 and 40 wk of gestation. The fetal cardiac electrical signal was sampled at a rate of 1,024 Hz by using Ag-AgCl electrodes positioned across the mother's abdomen, and fetal R waves were extracted by using adaptive signal processing techniques. To test for nonlinearity, ApEn for the original HR time series was compared with ApEn for three dynamic models: temporally uncorrelated noise, linearly correlated noise, and linearly correlated noise with nonlinear distortion. Each model had the same mean and SD in HR as the original time series, and one model also preserved the Fourier power spectrum. We estimated that noise accounted for 17.2-44.5% of the total between-fetus variance in ApEn. Nevertheless, ApEn for the original time series data still differed significantly from ApEn for the three dynamic models for both group comparisons and individual fetuses. We concluded that the HR time series, in low-risk human fetuses, could not be modeled as temporally uncorrelated noise, linearly correlated noise, or static filtering of linearly correlated noise.

Spontaneous motor activity in the perinatal infant before and after birth: stability in individual differences.

This study was undertaken to determine if a relationship existed between the duration of spontaneous general movements before and after birth. Twenty-two infants were examined three times as fetuses between 38 and 40 weeks gestational age and three times as neonates between 2 and 4 weeks postnatal age. Motor activity level during active sleep periods was quantified by direct sonographic visualization for fetuses and by videotaped images of trunk movement for neonates. We found that both fetuses and neonates exhibited stable individual differences in motor activity level. In addition, infants who moved at a certain rate as fetuses generally moved at the same relative rate as neonates up to 4-weeks postnatal age. Our findings suggested that individual differences in motor activity level in the 1st month following birth probably arise during fetal life.

High vagal tone is associated with more efficient regulation of homeostasis in low-risk human fetuses.

Homeostasis is maintained primarily by the parasympathetic nervous system and is thought to provide a physiological substrate for the development of complex behaviors. This investigation was undertaken to test the hypothesis that infants with high parasympathetic tone are more efficient regulators of homeostasis than infants with low parasympathetic tone. Respiratory sinus arrhythmia (RSA) was used as a measure of parasympathetic tone, and the efficiency of homeostatic control was quantified, for each infant, by the slope (SRSA) and correlation coefficient (RRSA) of the regression line relating fluctuations in heart period and fluctuations in RSA. To test our hypothesis, we examined the relationship between RSA and both SRSA and RRSA in 34 low-risk human fetuses between 36 and 40 weeks gestation. We found that fetuses who were parasympathetic-dominated had larger SRSA and RRSA values, and hence were more efficient regulators of homeostasis, than fetuses who were sympathetic-dominated. The results of our analyses are important because they establish, very early in development, a physiological basis for the relationship between vagal tone and the development of complex behaviors.

Pneumonia as a complication of pregnancy.

OBJECTIVE: To identify risk factors for the development of antepartum pneumonia and to describe maternal and perinatal outcome in pregnant women with pneumonia. METHODS: The study group consisted of 59 women with antepartum pneumonia. Pneumonia was defined by the presence of lower respiratory tract symptoms, radiographic findings, no other source of infection, and at least two of the following: oral temperature > or =38 degrees C, white blood cell count > or =15,000/ml, auscultatory findings, and/or positive sputum cultures. For comparison, a control group (n = 118) of pregnant women was formed by selecting the first mother who delivered immediately before and after an index study subject. RESULTS: Mothers in the study group were significantly more likely than women in the control group to have either a history of asthma (P = 0.022) or an admission hematocrit < or =30% (P < 0.001). Women with pneumonia were also more likely to receive a tocolytic agent (P < 0.001) and/or beta-methasone to enhance fetal lung maturity (P < 0.001). In addition, study subjects delivered at an earlier mean gestational age (P = 0.002) and had infants who weighed significantly less (P = 0.003) than mothers in the control group. Multivariate analysis indicated that women with asthma or anemia had more than a five-fold increase in the risk of developing pneumonia during pregnancy (P = 0.013), and mothers with pneumonia were significantly more likely to deliver before 34 weeks gestation (P = 0.04). CONCLUSIONS: Pneumonia during pregnancy was associated with maternal anemia and asthma. In addition, preterm labor with tocolysis and/or beta-methasone was more common in women with pneumonia, and these women were more likely to deliver preterm and have low birthweight infants compared to women without pneumonia.

Behavioral state affects heart rate response to low-intensity sound in human fetuses.

The cardiac orienting reflex is elicited by a low-intensity sound, it consists of a sustained heart rate (HR) deceleration, and it is a specific physiological correlate of cognitive processing. In this study we examined the relationship between behavioral state and the cardiac orienting reflex in 75 human fetuses between 36 and 40 weeks gestation. Each fetus was stimulated with a 30-s speech sound at an average intensity of 83 dB SPL in quiet sleep (QS) and active sleep (AS). The fetal cardiac electrical signal was captured transabdominally at a rate of 1024 Hz and fetal R-waves were extracted using adaptive signal processing. Fetal behavioral states were assigned based on HR pattern and the presence or absence of eye and general body movements. We found that a significant HR deceleration occurred, in both QS and AS, following stimulus onset. However, HR decelerations occurred more often in QS than AS; and for fetuses exhibiting a HR deceleration, the magnitude of the deceleration was greater in AS compared to QS. In addition, in AS female fetuses exhibited a larger, more sustained HR deceleratory response than male fetuses, but the seconds x gender interaction in QS was not significant. Based on these results, we concluded that behavioral state is an important determinant of the HR deceleratory response in human fetuses.

Pregnancy in women with spinal cord injuries.

Most women with spinal cord injuries (SCI) resume normal reproductive function, can have sexual relationships, and become pregnant. Pregnancy is not contraindicated in women with SCI, but pregnant women with acute or chronic SCI pose unique challenges for perinatal health care providers. The normal physiologic changes of pregnancy may predispose women with SCI to potentially life-threatening complications, including autonomic hyperreflexia, pyelonephritis, respiratory insufficiency, thrombophlebitis, and unattended delivery of the infant. This article reviews the effect of SCI on female reproduction, pregnancy, and labor, and summarizes the treatment of the pregnant woman with a spinal cord injury.

Hospital readmission for postpartum endometritis.

This study identified risk factors associated with readmission for postpartum endometritis. The study group consisted of 109 mothers (Group I) who were discharged after delivery and readmitted with endometritis. Control groups consisted of women who had endometritis immediately after delivery but who did not require readmission (Group II, n = 109), and women who had no intrapartum or puerperal infection and also were not readmitted (Group III, n = 109). Subjects in Groups II and III were matched to an index study subject for date of delivery and maternal age, race, and parity; and women in Groups I and III were also matched for route of delivery. Groups were compared in terms of demographic characteristics, intrapartum course, and clinical presentation. The data were analyzed with the t-test, chi2, and multiple logistic regression analyses, and a P value < .05 was considered significant. Women in Groups I and III delivered vaginally more often than mothers in Group II. In addition, mothers in Groups I and III had similar postpartum courses, no evidence of infection on discharge after delivery, and a similar period from delivery until postpartum discharge. Although women in Group I were more likely to have spontaneous rupture of membranes, a shorter latent period, and have fewer bilateral tubal ligations than mothers in Group II, multivariate analysis identified route of delivery as the only significant maternal variable associated with postpartum endometritis requiring readmission. Women who were readmitted for endometritis usually delivered vaginally, and the occurrence of late-onset postpartum endometritis was unrelated to the length of stay following delivery.

Methods used to diagnose premature rupture of membranes: a national survey of 812 obstetric nurses.

OBJECTIVE: To identify methods used to diagnose premature rupture of membranes (PROM). METHODS: A 14-item questionnaire was mailed to 1992 registered nurses certified in inpatient obstetrics to determine information on practice facility, obstetric services, procedures used to obtain vaginal fluids for testing, and methods used to diagnose PROM. RESULTS: A total of 812 (40.8%) surveys were available for analysis. Of tests used to confirm PROM, observation of pooling fluid in the posterior fornix and fern tests were much more likely to be used in teaching and military hospitals and in facilities with tertiary obstetric services than in private hospitals (all P values < .001). To obtain vaginal fluids for fern and nitrazine testing, the dry glove method (ie, insertion of a gloved hand or nitrazine strip into the vagina) was used significantly more often in private hospitals than in teaching or military facilities (P < .001). In addition, the dry glove method was used significantly more often (P < .001) and the speculum examination was used less often (P < .001) to collect vaginal fluids for testing when private physicians performed more than 75% of deliveries at a particular hospital. In contrast, vaginal fluid was obtained during a sterile speculum examination more often in facilities in which more than 75% of deliveries were performed by residents (P < .001), and/or when more than 75% of speculum examinations were performed by nursing personnel (P < .001). Multiple linear regression analyses indicated that observation of pooling fluid and use of the fern test were significantly associated with hospital type, percentage of deliveries by private physicians, and percentage of speculum examinations performed by nursing personnel (all P values < .001). CONCLUSION: A sterile speculum examination is used more often to obtain vaginal fluids for testing and to diagnose ruptured membranes in teaching or military facilities and when nursing personnel have been trained in speculum examinations.

Heart rate dynamics in low risk human fetuses.

Evaluation of nonlinear heart rate (HR) dynamics has received considerable attention in the pediatric literature because such analyses not only provide insight into underlying control mechanisms, but may also help to differentiate between normal and abnormal infants. The purpose of this study was to determine, in eight low risk human fetuses, if nonlinear HR dynamics could be identified by analyzing the dispersion of interbeat intervals at slow (Ds) and fast (Df) HRs. The fetal cardiac electrical signal was captured transabdominally at a resolution of +/- 1 ms. To test the null hypothesis, that the time series is the result of a linear stochastic process, Ds and Df for the original time series were compared with the values calculated for three linear models. The linear models were constructed to preserve the major statistical properties of the original time series, including the mean, SD, and the Fourier power spectrum. For each fetus, there was no evidence of nonlinear cardiac dynamics based on analyses of Ds and Df. In contrast, the distribution of adjacent R-R intervals and the pattern of change across three successive interbeat intervals both revealed significant nonlinearities in HR control in each fetus. If the difference between normal and abnormal infants is the result of aberrant control of nonlinear processes, then our findings indicate that parameters which describe the nonlinearity may be more useful then Ds and Df in assigning a risk status.

Clinical presentation of women readmitted with postpartum severe preeclampsia or eclampsia.

OBJECTIVE: To identify symptoms that prompted a group of women readmitted for postpartum severe preeclampsia or eclampsia to seek medical care. DESIGN: Retrospective, case-control. SETTING: Tertiary-care teaching hospital. SUBJECTS: The study group consisted of 53 women readmitted in the postpartum period with severe preeclampsia or eclampsia. The control group was matched two-to-one with an index study participant and consisted of 106 women who had intrapartum severe preeclampsia or eclampsia. MAIN OUTCOME MEASURES: Patient symptoms, physical findings, laboratory assays. RESULTS: Neurologic complaints, malaise, and nausea and vomiting were reported more often in women who were readmitted than in mothers with intrapartum preeclampsia (all p values less than .001). Headaches were positively correlated with systolic, diastolic, and mean arterial blood pressure in women who were readmitted (all p values less than .05), although there was no relationship between blood pressure and headaches in the control group. In addition, multivariate analysis revealed that study participants were more likely to deliver at full term, have headaches and malaise, have normal platelet values, and develop seizures than mothers in the control group, chi 2 = 155.7, p < .001. CONCLUSIONS: Women readmitted for postpartum severe preeclampsia or eclampsia have a clinical presentation that differs from that of intrapartum preeclampsia or eclampsia.

The antiphospholipid antibody syndrome: an overview.

The antiphospholipid antibody syndrome is characterized by the presence of maternal anticardiolipin antibodies and/or the lupus anticoagulant in association with recurrent pregnancy loss, thrombotic events, and/or thrombocytopenia. This disorder occurs rarely, but pregnant patients with antiphospholipid antibodies are at risk for adverse maternal and perinatal outcomes. This article reviews the antiphospholipid antibody syndrome, including its pathophysiology, clinical sequelae, diagnostic criteria, medical treatment, and nursing care.

Temporal stability in the distribution of behavioral states for individual human fetuses.

Although behavioral state analyses have been useful in differentiating between groups of normal and at-risk fetuses, the large between-subject differences in the percent time spent in the various behavioral states poses a major obstacle in identifying abnormal neurological functioning in individual fetuses. Does this variability represent a true difference in state organization between fetuses, or does it simply reflect individual fluctuations in state control at the time of observation? To answer this question, we examined each of 33 human fetuses for 4 h on three separate days between 38 and 40 weeks gestation. The percent time spent in each behavioral state and in transition and insertion periods was determined for each of the three 4-h study sessions, and within-subject analysis of variance was performed to obtain an objective measure of state profile consistency for each fetus. We found that, on the average, fetuses exhibited remarkable within-subject consistency in their state profiles. However, even among this group of low-risk fetuses, there were significant differences in the degree of state organization achieved by individual fetuses. These findings, which indicate the existence of a well-developed central nervous system before birth, suggest that individual differences in the consistency of behavioral state profiles may be indexing important between-subject differences in neurological development.

The heart rate deceleratory response in low-risk human fetuses: effect of stimulus intensity on response topography.

The purpose of this study was to determine the effect of stimulus intensity on heart rate response in 18 low-risk human fetuses between 37 and 40 weeks gestation. Each fetus was stimulated in quiet sleep with a 30-s voice sound at intensities of 80 dB and 90 dB. The fetal cardiac electrical signal was captured transabdominally at a rate of 1024 Hz and fetal R-waves were extracted using adaptive signal-processing techniques. We found that fetuses generally exhibited a 5- to 10-s decrease in heart rate following stimulus onset at an intensity of 80 dB. The response pattern changed from deceleratory to acceleratory when stimulus intensity was increased to 90 dB. Our findings suggest that a heart rate deceleration at low-stimulus intensity may be a component of the orienting reflex in the human fetus.

Similarities and differences in behavioral state organization during sleep periods in the perinatal infant before and after birth.

The purpose of this study was to determine the degree of consistency in behavioral state organization for 30 low-risk human participants examined as fetuses at 38-40 weeks gestation and again as neonates at approximately 2 weeks postnatal age. Behavioral states were assigned similarly for fetuses and neonates in terms of heart rate pattern and the presence or absence of eye and gross body movements. We found that the time spent in a sleep period was distributed among quiet sleep (QS), active sleep (AS), and indeterminate states in virtually identical proportions for fetuses and neonates. However, the only within-subject consistency between the fetal and neonatal periods was in the duration of complete QS epochs. Fetuses made fewer transitions between QS and AS, but neonates had shorter and more structured AS-->QS transitions. These findings suggest that, whereas central nervous system processes governing QS do not change appreciably, the control of AS undergoes significant changes in the 4 weeks spanning the fetal and neonatal periods. We believe that the duration of enclosed QS epochs provides the only stable measure of behavioral state development between the prenatal and postnatal periods.