Amniotic fluid sTREM-1 in normal pregnancy, spontaneous parturition at term and preterm, and intra-amniotic infection/inflammation

OBJECTIVE

Intra-amniotic infection/inflammation (IAI) is one of the most important mechanisms of disease in preterm birth. Triggering receptor expressed on myeloid cells (TREM)- 1 is a transmembrane glycoprotein expressed by neutrophils, macrophages and mature monocytes. TREM-1 is upregulated in biological fluids and tissues infected by Gram (+) and Gram (-) bacteria and fungi, amplifies the production of pro-inflammatory cytokines and chemokines, and its soluble form (sTREM-1) is released in the presence of infection. The aim of this study was to determine the effect of gestational age, parturition (term and preterm) and IAI in the amniotic fluid (AF) concentrations of sTREM-1.

STUDY DESIGN

This cross-sectional study included 434 patients in the following groups: (1) mid-trimester of pregnancy (14-18 weeks, n = 38); (2) normal pregnant women at term with (n = 39) and without (n = 39) labor; (3) patients with spontaneous preterm labor (PTL) and intact membranes classified into: (a) PTL who delivered at term (n = 99); (b) PTL who delivered preterm (<37 weeks gestation) without IAI (n = 80); and (c) PTL with IAI (n = 59); and (4) women with preterm prelabor rupture of membranes (PROM) with (n = 40) and without (n = 40) IAI. The AF concentration of sTREM-1 was determined by enzyme-linked immunoassay. Non-parametric statistics were used for analyses.

RESULTS

(1) sTREM-1 was detected in all the AF samples; (2) the median AF sTREM-1 concentration at term was higher than in the mid-trimester (4277.6 pg/ml vs. 1140.4 pg/ml; p < 0.001); (3) among patients with PTL, the median AF sTREM-1 concentration was higher in patients with IAI than in those without IAI (6154.4 pg/ml vs. 3282.8 pg/ml; p < 0.001) and those with PTL who delivered at term (6154.4 pg/ml vs. 2794 pg/ml; p < 0.001); (4) patients with preterm PROM with IAI had a higher median AF sTREM-1 concentration than those without IAI (7893.1 pg/ml vs. 3386.6 pg/ml; p < 0.001); (5) no differences were observed in the median AF sTREM-1 concentration between patients with spontaneous labor at term and those at term not in labor (4712.4 pg/ml vs. 4277.6 pg/ml; respectively p = 0.4); and 6) an AF sTREM-1 concentration >or=6416 pg/ml (derived from a ROC curve) had a sensitivity of 72% and a specificity of 89% for the diagnosis of intra-amniotic infection.

CONCLUSIONS

sTREM-1 is a physiologic constituent of the AF, and its concentration: (1) is significantly elevated in the presence of IAI; (2) increases with advancing gestation; and (3) does not change in the presence of spontaneous labor at term. We propose that sTREM-1 play a role in the innate immune response against intra-amniotic infection.

High tissue factor activity and low tissue factor pathway inhibitor concentrations in patients with preterm labor

OBJECTIVE

Preterm labor (PTL) has been associated with an increased thrombin generation in the maternal circulation and amniotic fluid. Tissue factor (TF) is a potent initiator of the coagulation cascade, which can trigger the hemostatic system to generate thrombin. The aims of this study were to determine whether spontaneous PTL with intact membranes is associated with changes in the maternal plasma concentrations and activity of TF as well as tissue factor pathway inhibitor (TFPI).

METHODS

This cross-sectional study included women in the following groups: (1) normal pregnancies (n = 86); (2) term pregnancies in spontaneous labor (TIL) (n = 67) and not in labor (TNL) (n = 88); and (3) patients with spontaneous PTL and intact membranes (n = 136) that were classified into three sub-groups: (a) PTL without intra-amniotic infection and/or inflammation (IAI) who delivered at term (n = 49); (b) PTL without IAI who delivered preterm (n = 54); and (c) PTL with IAI who delivered preterm (n = 33). Plasma concentrations of TF and TFPI were measured by ELISA, and their activity was measured by chromogenic assays. Non-parametric statistics were used for analysis.

RESULTS

(1) Among women at term, those with spontaneous labor had a higher median maternal plasma TF and a lower median TFPI concentration than those without labor. (2) Patients with PTL had a significantly lower median maternal plasma TFPI concentration than that of normal pregnant women, regardless of the presence of IAI. (3) There was no significant difference in the median maternal plasma TF concentration between patients with a normal pregnancy and those with PTL. (4) In contrast, the median maternal plasma TF activity was higher among patients with PTL than in women with normal pregnancies, regardless of the presence of IAI or preterm delivery. (5) However, maternal plasma TFPI activity did not differ among the study groups.

CONCLUSION

Women with preterm parturition, in contrast to those in labor at term, have a higher TF activity and a lower TFPI concentration, without a significant change in the median maternal plasma TF concentration. These observations suggest that the increased thrombin generation reported in patients with PTL may be the result of activation of the extrinsic pathway of the coagulation cascade. In addition, the increased thrombin generation reported in patients with PTL could be due to insufficient anti-coagulation, as reflected by the low maternal plasma TFPI concentration.

Hyperresistinemia - a novel feature in systemic infection during human pregnancy

PROBLEM

Resistin, originally described as an adipokine, has emerged as a potent pro-inflammatory protein associated with both acute and chronic inflammation. Moreover, resistin has been proposed as a powerful marker of sepsis severity, as well as a predictor of survival of critically ill non-pregnant patients. The aim of this study was to determine whether pyelonephritis during pregnancy is associated with changes in maternal plasma resistin concentrations.

METHODS OF STUDY

This cross-sectional study included the following groups: (i) normal pregnant women (n = 85) and (ii) pregnant women with pyelonephritis (n = 40). Maternal plasma resistin concentrations were determined by ELISA. Non-parametric statistics was used for analyses.

RESULTS

(i) The median maternal plasma resistin concentration was higher in patients with pyelonephritis than in those with a normal pregnancy (P < 0.001); (ii) among patients with pyelonephritis, the median maternal resistin concentration did not differ significantly between those with and without a positive blood culture (P = 0.3); (iii) among patients with pyelonephritis who were diagnosed with systemic inflammatory response syndrome (SIRS), those who fulfilled > or =3 criteria for SIRS had a significantly higher median maternal plasma resistin concentration than those who met only two criteria; and (iv) maternal WBC count positively correlated with circulating resistin concentration (r = 0.47, P = 0.02).

CONCLUSION

Hyperresistinemia is a feature of acute pyelonephritis during pregnancy. The results of this study support the role of resistin as an acute-phase protein in the presence of bacterial infection during pregnancy.

Evidence of maternal platelet activation, excessive thrombin generation, and high amniotic fluid tissue factor immunoreactivity and functional activity in patients with fetal death

OBJECTIVE

Fetal death can lead to disseminated intravascular coagulation or fetal death syndrome. However, currently it is not clear what are the changes in the coagulation system in patients with a fetal death without the fetal death syndrome. This study was undertaken to determine: (1) whether fetal death in the absence of fetal death syndrome is associated with changes in hemostatic markers in maternal plasma and amniotic fluid; and (2) whether maternal hypertension or placental abruption are associated with further changes in the hemostatic profile of these patients.

METHODS

A cross-sectional study included the following: (1) determination of changes in markers of coagulation and platelet activation in patients with a normal pregnancy (n = 71) and patients with fetal demise (FD) without disseminated intravascular coagulation (n = 65); (2) determination of the amniotic fluid (AF)-tissue factor concentration and activity, as well as the concentrations of thrombin-antithrombin III (TAT) complexes in patients with a normal pregnancy (n = 25) and those with a FD (n = 36) who underwent amniocentesis. Plasma and AF concentrations of TAT complexes and TF (an index of thrombin generation), as well as maternal plasma concentrations of sCD40L (a marker of platelet activation), tissue factor pathway inhibitor (TFPI) and prothrombin fragments (PF) 1 + 2 (also an indicator of in vivo thrombin generation) were measured by ELISA. TF and TFPI activity were measured using chromogenic assays.

RESULTS

(1) patients with FD without hypertension had a higher median maternal plasma sCD40L concentration than normal pregnant women (P < 0.001); (2) patients with FD had a higher median maternal plasma TAT III complexes than women with a normal pregnancy (P < 0.001); (3) the median AF-TF concentration and activity were higher in the FD group than in the normal pregnancy group (P < 0.001 for both); (4) patients with preeclampsia and FD had a higher median maternal plasma immunoreactive TF concentration than both normotensive patients with FD and women with normal pregnancies (P < 0.001 and P = 0.001, respectively); (5) the median plasma TF activity was higher in patients with preeclampsia and FD than that of women with normal pregnancies (P = 0.003); (6) among patients with a FD, those with placental abruption had a higher median AF-TAT complexes concentration than those without abruption (P = 0.0004).

CONCLUSIONS

Our findings indicate that: (1) mothers with a FD have evidence of increased in vivo thrombin generation and platelet activation than women with normal pregnancies; (2) patients with a FD and hypertension had a higher degree of TF activation than those with fetal death but without hypertension; (3) the AF of women with a FD had a higher median TF concentration and activity than that of normal pregnant women. AF can be a potential source for tissue factor and it participates in the development of fetal death syndrome in patients with a retained dead fetus.

Maternal plasma visfatin in preterm labor

OBJECTIVE

Visfatin, a novel adipokine with diabetogenic and immunoregulatory properties, has been implicated in the pathophysiology of insulin resistance, as well as in various acute and chronic inflammatory disorders. We have previously reported that amniotic fluid concentrations of visfatin are higher in patients with preterm labor (PTL) and intra-amniotic infection than in patients with PTL without infection. The aim of this study was to determine whether spontaneous PTL with intact membranes and intra-amniotic infection/inflammation (IAI) is associated with changes in maternal plasma circulating visfatin concentrations.

STUDY DESIGN

This cross-sectional study included patients in the following groups: (1) normal pregnant women (n = 123); (2) patients with an episode of PTL and intact membranes without IAI who delivered at term (n = 57); (3) PTL without IAI who delivered preterm (n = 47); and (4) PTL with IAI who delivered preterm (n = 57). Plasma visfatin concentrations were determined by ELISA. Non-parametric statistics were used for analysis.

RESULTS

(1) PTL with IAI leading to preterm delivery was associated with a higher median maternal plasma concentration of visfatin than normal pregnancy; (2) among patients with PTL, those with IAI had the highest median maternal concentration of visfatin; (3) the changes in maternal plasma visfatin remained significant after adjusting for maternal age, body mass index, gestational age at sampling, and birth weight.

CONCLUSION

(1) PTL with IAI is characterized by high maternal circulating visfatin concentrations; (2) these findings suggest that visfatin plays a role in the regulation of the metabolic adaptations to insults resulting in PTL in the context of IAI.

Maternal anti-protein Z antibodies in pregnancies complicated by pre-eclampsia, SGA and fetal death

OBJECTIVE

Low maternal plasma protein Z (PZ) concentrations were reported in patients with pre-eclampsia (PE), a small for gestational age (SGA) neonate, and a fetal demise (FD). Anti-protein Z antibodies (APZ-AB) have been proposed as a possible underlying mechanism leading to low plasma PZ concentrations. The objective of this study was to determine the maternal plasma concentration of APZ-AB in women with a normal pregnancy, and patients with PE, an SGA neonate or a FD.

STUDY DESIGN

A cross-sectional study included women in the following groups: (1) non-pregnant women (n = 45); and pregnant women with: (2) normal pregnancies (n = 70); (3) PE (n = 123); (4) SGA neonates (n = 51); and (5) a FD (n = 51). Plasma concentrations of anti-protein Z IgM and IgG antibodies were measured by ELISA. Elevated APZ-AB was defined as >75th, 90th and 95th percentile of the normal pregnancy group. Non-parametric statistics were used for analyses.

RESULTS

(1) Patients with an SGA neonate had a higher median maternal plasma IgG APZ-AB concentration than women with normal pregnancies (p < 0.001), and patients with PE (p < 0.001) or with a FD (p = 0.001). (2) The proportion of patients with a maternal plasma IgM APZ-AB concentration >90th percentile was higher in the SGA group than in the PE group (p = 0.01). (3) Patients with PE maternal plasma IgM APZ-AB concentration >90th percentile had a higher rate of villous thrombosis (p = 0.03) and persistent muscularization of basal plate arteries (p = 0.01) than those with IgM APZ-AB concentration <90th percentile; and (5) Patients with FD and maternal plasma IgM APZ-AB concentration >90th percentile had a higher rate of umbilical phlebitis and arteritis than those with IgM APZ-AB concentration <90th percentile (p = 0.003).

CONCLUSIONS

(1) Patients with SGA neonates have a higher median plasma concentration of IgG APZ-AB than normal pregnant women, or patients with PE or FD; and (2) maternal plasma IgM APZ-AB concentration >90th percentile was associated with vascular placental lesions in patients with PE, but not in those with an SGA neonate, suggesting that in a subset of patients, these antibodies can be associated with abnormal placentation and pregnancy complications.

Activation of the alternative pathway of complement is a feature of pre-term parturition but not of spontaneous labor at term

PROBLEM

Plasma concentrations of fragment Bb (FBb) are a marker for activation of the alternative pathway of the complement system. High concentrations of FBb in maternal blood, as early as the first trimester, are associated with subsequent spontaneous pre-term delivery <34 weeks of gestation. The aim of this study was to determine whether spontaneous pre-term labor (PTL) with intact membranes, intra-amniotic infection/inflammation (IAI) or labor at term are associated with alterations in circulating maternal FBb concentrations.

METHOD OF STUDY

This cross-sectional study included women in the following groups: (i) non-pregnant (n = 40); (ii) normal pregnancy (gestational age range 20-36, 6/7 weeks, n = 63); (iii) women at term not in labor (n = 70); (iv) women at term in spontaneous labor (n = 59); (v) patients with an episode of PTL who delivered at term (n = 62); (vi) PTL without IAI who delivered pre-term (n = 30); and (vii) PTL with IAI who delivered pre-term (n = 67). Maternal plasma FBb concentrations were determined by ELISA.

RESULTS

(i) Among patients with PTL, those who had a pre-term delivery either with IAI (1.21 microg/mL, IQR 0.77-2.16) or without IAI (1.13 microg/mL, IQR 0.92-2.08) had a higher median maternal plasma FBb concentration than those who delivered at term (0.86 microg/mL, IQR 0.64-1.57; P = 0.007 and P = 0.026, respectively); (ii) there was no difference in the median plasma FBb concentration between patients with and without IAI who delivered pre-term (P = 0.9); (iii) in contrast, spontaneous labor at term was not associated with a significant change in the maternal plasma FBb concentration (P = 0.8); (iv) maternal plasma concentration of FBb did not differ significantly between normal pregnant women and the non-pregnant controls (P = 0.8) and were not correlated with advancing gestational age (r = -0.28, P = 0.8).

CONCLUSION

(i) Pre-term parturition is associated with activation of the alternative complement pathway in maternal circulation; (ii) such activation is not detectable in spontaneous labor at term; (iii) IAI does not explain the activation of the alternative pathway of complement in PTL. Collectively, these observations suggest that pre-term and term labors have fundamental differences in the regulation of innate immunity.

Fragment Bb in amniotic fluid: evidence for complement activation by the alternative pathway in women with intra-amniotic infection/inflammation

OBJECTIVE

Fragment Bb is an activator of the alternative pathway of the complement system. Recently, increased first trimester maternal plasma concentrations of this fragment were reported in patients destined to have a spontaneous preterm delivery before 34 weeks of gestation. The aim of this study was to determine whether the amniotic fluid (AF) concentrations of fragment Bb change with gestational age, spontaneous labor (term and preterm) and in the presence of intra-amniotic infection/inflammation (IAI).

STUDY DESIGN

This cross-sectional study included patients in the following groups: (1) mid-trimester (n = 64); (2) term in spontaneous labor (n = 70); (3) term not in labor (n = 43); (4) spontaneous preterm labor (PTL) who delivered at term (n = 76); (5) PTL without IAI who delivered preterm (n = 73); (6) PTL with IAI (n = 76); (7) preterm prelabor rupture of membranes (PROM) without IAI (n = 71); and (8) preterm PROM with IAI (n = 71). Fragment Bb concentration in AF was determined by an enzyme-linked immunoassay. Non-parametric statistics were used for analyses.

RESULTS

(1) Fragment Bb was detected in all AF samples (n = 544); (2) The median AF concentration of fragment Bb in patients at term not in labor was significantly higher than that of those in the mid-trimester [2.42 microg/ml, interquartile range (IQR) 1.78-3.22 vs. 1.64 microg/ml, IQR 1.06-3.49; p < 0.001]; (3) Among patients with PTL, those with IAI had a higher median AF fragment Bb concentration than that of woman without IAI, who delivered preterm (4.82 microg/ml, IQR 3.32-6.08 vs. 3.67 microg/ml, IQR 2.35-4.57; p < 0.001) and than that of women with an episode of PTL, who delivered at term (3.21 microg/ml, IQR 2.39-4.16; p < 0.001); (4) Similarly, among patients with preterm PROM, the median AF fragment Bb concentration was higher in individuals with IAI than in those without IAI (4.24 microg/ml, IQR 2.58-5.79 vs. 2.79 microg/ml, IQR 2.09-3.89; p < 0.001). (5) Among patients at term, the median AF fragment Bb concentration did not differ between women with spontaneous labor and those without labor (term in labor: 2.47 microg/ml, IQR 1.86-3.22; p = 0.97).

CONCLUSIONS

(1) Fragment Bb, an activator of the alternative complement pathway, is a physiologic constituent of the AF, and its concentration increases with advancing gestational age; (2) AF concentrations of fragment Bb are higher in pregnancies complicated with IAI; and (3) labor at term is not associated with changes in the AF concentrations of fragment Bb. These findings suggest a role for fragment Bb in the host immune response against IAI.

Amniotic fluid soluble human leukocyte antigen-G in term and preterm parturition, and intra-amniotic infection/inflammation

OBJECTIVE

Circulating soluble human leukocyte antigen-G (sHLA-G) has been associated with pregnancy complications, and determination of sHLA-G concentrations in amniotic fluid (AF) has been reported in normal pregnancies. Our aim was to determine if the AF concentrations of sHLA-G change with advancing gestation, spontaneous labor at term, and in patients with spontaneous preterm labor (PTL) with intact membranes, as well as in those with preterm prelabor rupture of membranes (PROM), in the presence or absence of intra-amniotic infection/inflammation (IAI).

STUDY DESIGN

This cross-sectional study included the following groups: (1) mid-trimester (n = 55); (2) normal pregnancy at term with (n = 50) and without (n = 50) labor; (3) spontaneous PTL with intact membranes divided into: (a) PTL who delivered at term (n = 153); (b) PTL who delivered preterm without IAI (n = 108); and (c) PTL with IAI (n = 84); and (4) preterm PROM with (n = 46) and without (n = 44) IAI. sHLA-G concentrations were determined by ELISA. Non-parametric statistics were used for analysis.

RESULTS

(1) Among patients with PTL, the median AF sHLA-G concentration was higher in patients with IAI than in those without IAI or women that delivered at term (p < 0.001 for both comparisons); (2) Similarly, patients with preterm PROM and IAI had higher median AF sHLA-G concentrations than those without IAI (p = 0.004); (3) Among patients with PTL and delivery, those with histologic chorioamnionitis and/or funisitis had a higher median AF sHLA-G concentration than those without histologic inflammation (p < 0.001); and (4) The median AF sHLA-G concentration did not change with advancing gestational age.

CONCLUSIONS

AF sHLA-G concentrations are elevated in preterm parturition associated to IAI as well as in histologic chorioamnionitis. We propose that sHLA-G may participate in the regulation of the host immune response against intra-amniotic infection.

A subset of patients destined to develop spontaneous preterm labor has an abnormal angiogenic/anti-angiogenic profile in maternal plasma: evidence in support of pathophysiologic heterogeneity of preterm labor derived from a longitudinal study

OBJECTIVE

An imbalance between angiogenic and anti-angiogenic factors in maternal blood has been observed in several obstetrical syndromes including preeclampsia, pregnancies with fetal growth restriction and fetal death. Vascular lesions have been identified in a subset of patients with spontaneous preterm labor (PTL). It is possible that PTL may be one of the manifestations of an anti-angiogenic state. The aim of this study was to determine if patients prior to the clinical diagnosis of PTL leading to preterm delivery had plasma concentrations of angiogenic and anti-angiogenic factors different from normal pregnant women.

STUDY DESIGN

This longitudinal nested case-control study included normal pregnant women (n = 208) and patients with PTL leading to preterm delivery (n = 52). Maternal blood samples were collected at 6 gestational age intervals from 6 to 36.9 weeks of gestation. The end point (time of diagnosis) of the study, 'True PTL', was defined as patients presenting with PTL and delivered within 1 day. Plasma concentrations of sVEGFR-1, sVEGFR-2, sEng and PlGF were determined by ELISA. Analysis was performed with both cross-sectional and longitudinal (mixed effects model) approaches.

RESULTS

(1) Plasma sEng concentration in patients destined to develop PTL was higher than that in normal pregnant women from 15-20 weeks of gestation. The difference became statistical significant at 28 weeks of gestation, or approximately 5-10 weeks prior to the diagnosis of 'true PTL'. (2) Backward analysis suggests that plasma concentrations of PlGF and sVEGFR-2 were lower, and those of sVEGFR-1 were higher in patients with PTL than in normal pregnant women less than 5 weeks prior to the diagnosis of 'true PTL'; and (3) Plasma concentrations of sEng and sVEGFR-1 were higher and those of PlGF and sVEGFR-2 were lower in patients diagnosed with PTL and delivery within 1 day than in normal pregnant women who delivered at term.

CONCLUSION

The changes in sEng are demonstrable several weeks prior to the onset of preterm parturition. In contrast, the changes in the other angiogenic proteins are present close to the onset of PTL and delivery. This observation supports the view that an imbalance of angiogenic factors participates in the pathophysiology of spontaneous preterm parturition.

Differential expression pattern of genes encoding for anti-microbial peptides in the fetal membranes of patients with spontaneous preterm labor and intact membranes and those with preterm prelabor rupture of the membranes

OBJECTIVE

Increased amniotic fluid concentrations of anti-microbial peptides, components of the innate immune system, have been reported in patients with preterm labor (PTL) with intact membranes and intra-amniotic infection and/or inflammation (IAI), as well as in patients with preterm prelabor rupture of the membranes (PPROM). This study was designed to confirm these results using a targeted approach, detecting DEFA1, DEFB1, GNLY, and S100A9 gene expression in the choriamniotic membranes in pregnancies complicated with PTL and intact membranes or PPROM, with and without histologic chorioamnionitis.

STUDY DESIGN

Human fetal membranes were obtained from patients in the following groups: (1) PTL with intact membranes (n = 15); (2) PTL with intact membranes with histologic chorioamnionitis (n = 12); (3) PPROM (n = 17); and (4) PPROM with histologic chorioamnionitis (n = 21). The mRNA expression of alpha-defensin-1, beta-defensin-1, calgranulin B and granulysin in the fetal membranes was determined by qRT-PCR.

RESULTS

(1) The expression of alpha-defensin-1 mRNA in the fetal membranes was higher in patients with PTL and intact membranes with histologic chorioamnionitis, than those without chorioamnionitis (19.4-fold, p < 0.001); (2) Among patients with histologic chorioamnionitis, patients with PTL and intact membranes had a higher alpha-defensin-1 mRNA expression than those with PPROM (5.5-fold, p = 0.003); (3) Histologic chorioamnionitis was associated with a higher calgranulin B mRNA expression in the chorioamniotic membranes of patients with both PTL and intact membranes (7.9-fold, p = 0.03) and PPROM (7.6-fold, p < 0.0001); (4) The expression of calgranulin B mRNA in the fetal membranes was higher in patients with PTL and intact membranes without histologic chorioamnionitis than in those with PPROM without histologic chorioamnionitis (2.7-fold, p = 0.03); (5) There were no differences in the expression of beta-defensin-1 and granulysin in the chorioamniotic membranes between the study groups even in the presence of histologic chorioamnioniotis.

CONCLUSIONS

(1) Among patients with histologic chorioamnionitis, the mRNA expression of alpha-defensin-1 and calgranulin B in the fetal membranes of patients with PTL and intact membranes as well as that of calgranulin B in the fetal membranes of patients with PPROM is higher than in the membranes of those without histologic chorioamnionitis; (2) histologic chorioamnionitis is associated with differences in the pattern of alpha-defensin-1 mRNA expression in the fetal membranes in patients with PTL and intact membranes and those with PPROM.

Plasma soluble endoglin concentration in pre-eclampsia is associated with an increased impedance to flow in the maternal and fetal circulations

OBJECTIVES

To examine the relationship between abnormalities in uterine (UtA) and/or umbilical artery (UA) Doppler velocimetry and maternal plasma concentrations of soluble endoglin (sEng) in patients with pre-eclampsia (PE).

METHODS

A cross-sectional study was conducted in 135 normal pregnant women and 69 patients with PE. Patients with PE were subclassified into four groups: those who had Doppler abnormalities in both the UtA and UA, patients who had Doppler abnormalities in the UtA alone, those who had Doppler abnormalities in the UA alone, and patients without Doppler abnormalities in either vessel. Plasma concentrations of sEng were determined by enzyme-linked immunosorbent assay.

RESULTS

Among patients with PE, those with abnormal UtA and UA Doppler velocimetry had the highest median plasma concentration of sEng compared with any other group (P < 0.001, Kruskal-Wallis test). Women with PE with normal Doppler velocimetry in both vessels had the lowest median plasma concentration of sEng. There was a significant relationship between plasma concentrations of sEng and mean UtA resistance index (Spearman Rho = 0.5, P < 0.001) as well as UA pulsatility index (Spearman Rho = 0.4, P = 0.002). Multiple regression analysis suggested that Doppler abnormalities in the UtA and UA as well as gestational age at blood sampling contributed to plasma sEng concentrations (P < 0.001).

CONCLUSIONS

Abnormalities of impedance to blood flow in the UtA and UA are associated with an excess of sEng in the circulation of mothers with PE. These findings suggest that the 'antiangiogenic state' in PE is partially reflected in abnormalities of Doppler velocimetry.

Maternal plasma concentration of the pro-inflammatory adipokine pre-B-cell-enhancing factor (PBEF)/visfatin is elevated in pregnant patients with acute pyelonephritis

PROBLEM

Visfatin/pre-B-cell-enhancing factor (PBEF) has been implicated in the regulation of the innate immune system, as well as in glucose metabolism. Specifically, visfatin plays a requisite role in delayed neutrophil apoptosis in patients with sepsis. The aim of this study was to determine whether pyelonephritis during pregnancy is associated with changes in maternal plasma visfatin concentration in normal weight and overweight/obese patients.

METHOD OF STUDY

This cross-sectional study included the following groups: (1) normal pregnant women (n = 200) and (2) pregnant women with pyelonephritis (n = 40). Maternal plasma visfatin concentrations were determined by ELISA. Non-parametric statistics was used for analyses.

RESULTS

(1) The median maternal plasma visfatin concentration was significantly higher in patients with pyelonephritis than in those with a normal pregnancy; (2) among overweight/obese pregnant women, those with pyelonephritis had a significantly higher median plasma visfatin concentration than women with a normal pregnancy; and (3) pyelonephritis was independently associated with higher maternal plasma visfatin concentrations after adjustment for maternal age, pre-gestational body mass index, smoking status, gestational age at sampling, and birthweight.

CONCLUSION

Acute pyelonephritis during pregnancy is associated with a high circulating maternal visfatin concentration. These findings suggest that visfatin/PBEF may play a role in the regulation of the complex and dynamic crosstalk between inflammation and metabolism during pregnancy.

Low circulating maternal adiponectin in patients with pyelonephritis: adiponectin at the crossroads of pregnancy and infection

OBJECTIVE

An emerging theme in modern biology is that adipose tissue can respond to metabolic stress, and to inflammatory stimuli, by regulating the secretion of a complex network of soluble mediators, termed adipokines. Adiponectin, the most prevalent circulating adipokine in human, has profound insulin-sensitizing and anti-inflammatory properties. Indeed, the notion that adiponectin plays an important role in the interactions between the metabolic and the immune systems has been strongly suggested. Thus, the aim of this study was to determine if pyelonephritis during pregnancy is associated with changes in maternal serum adiponectin concentrations.

STUDY DESIGN

This cross-sectional study included women in the following groups: 1) normal pregnant women (n=200); and 2) pregnant women with pyelonephritis (n=50). Maternal plasma adiponectin concentrations were determined by ELISA. Non-parametric statistics were used for analyses.

RESULTS

1) The median maternal plasma adiponectin concentration was lower in patients with pyelonephritis than in those with a normal pregnancy (P<0.001); 2) among pregnant women with a normal weight, patients with pyelonephritis had a lower median plasma adiponectin concentration than those with a normal pregnancy (P<0.001); 3) similarly, among overweight/obese patients, those with pyelonephritis had a lower median plasma adiponectin concentration than those with a normal pregnancy (P<0.001); and 4) the presence of pyelonephritis was independently associated with maternal plasma adiponectin concentrations after adjustment for maternal age, smoking, gestational age at sampling, and pregestational body mass index (BMI).

CONCLUSION

1) The findings that acute pyelonephritis in pregnancy is characterized by low maternal plasma concentrations of adiponectin in both lean and overweight/obese patients are novel and concur with the antiinflammatory properties of adiponectin; and 2) the results of this study support the notion that adiponectin may play a role in the intricate interface between inflammation and metabolism during pregnancy.

The prognosis of pregnancy conceived despite the presence of an intrauterine device (IUD)

OBJECTIVE

Intrauterine devices (IUDs) are used for contraception worldwide; however, the management of pregnancies with an IUD poses a clinical challenge. The purpose of this study was to determine the outcome of pregnancy in patients with an IUD.

STUDY DESIGN

A retrospective cohort study (December 1997-June 2007) was conducted. The cohort consisted of 12,297 pregnancies, of which 196 had an IUD. Only singleton pregnancies were included. Logistic regression analysis was used to adjust for potential confounders between the groups.

RESULTS

1) Pregnancies with an IUD were associated with a higher rate of late miscarriage, preterm delivery, vaginal bleeding, clinical chorioamnionitis, and placental abruption than those without an IUD; 2) among patients with available histologic examination of the placenta, the rate of histologic chorioamnionitis and/or funisitis was higher in patients with an IUD than in those without an IUD (54.2% vs. 14.7%; P<0.001). Similarly, among patients who underwent an amniocentesis, the prevalence of microbial invasion of the amniotic cavity (MIAC) was also higher in pregnant women with an IUD than in those without an IUD (45.9% vs. 8.8%; P<0.001); and 3) intra-amniotic infection caused by Candida species was more frequently present in pregnancies with an IUD than in those without an IUD (31.1% vs. 6.3%; P<0.001).

CONCLUSION

Pregnant women with an IUD are at a very high risk for adverse pregnancy outcomes. This finding can be attributed, at least in part, to the high prevalence of intra-amniotic infection and placental inflammatory lesions observed in pregnancies with an IUD.

Evidence for complement activation in the amniotic fluid of women with spontaneous preterm labor and intra-amniotic infection

OBJECTIVE

The complement system plays an important role in host defense against infection. Concentrations of complement split products or anaphylatoxins (C3a, C4a, and C5a) in biological fluids are considered to reflect complement activation. The purpose of this study was to determine if term and preterm parturition are associated with evidence of complement activation in the amniotic fluid.

STUDY DESIGN

Amniotic fluid (AF) samples were collected from 270 women in the following groups: (1) normal pregnant women in midtrimester (n = 70), (2) term not in labor (n = 23), (3) term in labor (n = 48), and (4) preterm labor (PTL) (n = 129). PTL was categorized into: (a) PTL without microbial invasion of the amniotic cavity (MIAC) who delivered at term (n = 42), (b) PTL who delivered preterm without MIAC (n = 57), and (c) PTL with MIAC (n = 30). C5a, C4a, and C3a concentrations in amniotic fluid were determined by ELISA. Nonparametric tests were used for statistical analysis.

RESULTS

(1) The median AF C5a concentration was higher in women at term than that of those in the midtrimester (p = 0.02); (2) Spontaneous labor at term was not associated with changes in AF concentrations of anaphylatoxins C3a, C4a, and C5a (all p > 0.05); (3) Among patients with PTL who delivered preterm, those with MIAC had higher AF C4a and C5a concentrations than those without infection (p < 0.01); and (4) AF C3a, C4a, and C5a concentrations were higher in patients with PTL with MIAC than in those with PTL without MIAC who delivered at term.

CONCLUSION

Patients with spontaneous preterm labor and intact membranes with microbial invasion of the amniotic cavity had higher median amniotic fluid concentration of complement split products C3a, C4a, and C5a than patients without intra-amniotic infection. These findings suggest that preterm labor in the context of infection is associated with activation of the complement system.

Mitochondrial manganese superoxide dismutase mRNA expression in human chorioamniotic membranes and its association with labor, inflammation, and infection

OBJECTIVE

Human parturition is characterized by the activation of genes involved in acute inflammatory responses in the fetal membranes. Manganese superoxide dismutase (Mn SOD) is a mitochondrial enzyme that scavenges reactive oxygen species (ROS). Mn SOD is up-regulated in sites of inflammation and has an important role in the down-regulation of acute inflammatory processes. Therefore, the aim of this study was to determine the differences in Mn SOD mRNA expression in the fetal membranes in patients with term and preterm labor (PTL) as well as in acute chorioamnionitis.

STUDY DESIGN

Fetal membranes were obtained from patients in the following groups: (1) term not in labor (n = 29); (2) term in labor (n = 29); (3) spontaneous PTL with intact mebranes (n = 16); (4) PTL with histological chorioamnionitis (n = 12); (5) preterm prelabor rupture of the membranes (PPROM; n = 17); and (6) PPROM with histological chorioamnionitis (n = 21). Mn SOD mRNA expression in the membranes was determined by quantitative real-time reverse transcription-polymerase chain reaction.

RESULTS

(1) Mn SOD mRNA expression was higher in the fetal membranes of patients at term in labor than those not in labor (2.4-fold; p = 0.02); (2) the amount of Mn SOD mRNA in the fetal membranes was higher in PTL than in term labor or in PPROM (7.2-fold, p = 0.03; 3.2-fold, p = 0.03, respectively); (3) Mn SOD mRNA expression was higher when histological chorioamnionitis was present both among patients with PPROM (3.8-fold, p = 0.02) and with PTL (5.4-fold, p = 0.02) than in patients with these conditions without histological chorioamnionitis; (4) expression of Mn SOD mRNA was higher in PTL with chorioamnionitis than in PPROM with chorioamnionitis (4.3-fold, p = 0.03).

CONCLUSION

The increase in Mn SOD mRNA expression by fetal membranes in term labor and in histological chorioamnionitis in PTL and PPROM suggests that the fetus deploys anti-oxidant mechanisms to constrain the inflammatory processes in the chorioamniotic membranes.

A prospective cohort study of the value of maternal plasma concentrations of angiogenic and anti-angiogenic factors in early pregnancy and midtrimester in the identification of patients destined to develop preeclampsia

OBJECTIVE

Changes in the maternal plasma concentrations of angiogenic (placental growth factor (PlGF) and vascular endothelial growth factor (VEGF)) and anti-angiogenic factors (sEng and vascular endothelial growth factor receptor-1 (sVEGFR-1)) precede the clinical presentation of preeclampsia. This study was conducted to examine the role of maternal plasma PlGF, sEng, and sVEGFR-1 concentrations in early pregnancy and midtrimester in the identification of patients destined to develop preeclampsia.

METHODS

This longitudinal cohort study included 1622 consecutive singleton pregnant women. Plasma samples were obtained in early pregnancy (6-15 weeks) and midtrimester (20-25 weeks). Maternal plasma PlGF, sEng, and sVEGFR-1 concentrations were determined using sensitive and specific immunoassays. The primary outcome was the development of preeclampsia. Secondary outcomes included term, preterm, and early-onset preeclampsia. Receiving operating characteristic curves, sensitivity, specificity, positive and negative likelihood ratios, and multivariable logistic regression were applied. A p-value of <0.05 was considered significant.

RESULTS

(1) The prevalence of preeclampsia, term, preterm, (<37 weeks) and early-onset preeclampsia (<34 weeks) was 3.8 (62/1622), 2.5 (40/1622), 1.4 (22/1622) and 0.6% (9/1622), respectively; (2) Higher likelihood ratios were provided by ratios of midtrimester plasma concentrations of PlGF, sEng, and sVEGFR-1 than single analytes; (3) Individual angiogenic and anti-angiogenic factors did not perform well in the identification of preeclampsia as a whole; in particular, they perform poorly in the prediction of term preeclampsia; (4) In contrast, a combination of these analytes such as the PlGF/sEng ratio, its delta and slope had the best predictive performance with a sensitivity of 100%, a specificity of 98-99%, and likelihood ratios for a positive test of 57.6, 55.6 and 89.6, respectively, for predicting early-onset preeclampsia.

CONCLUSIONS

(1) The PlGF/sEng ratio and its delta and slope had an excellent predictive performance for the prediction of early-onset preeclampsia, with very high likelihood ratios for a positive test result and very low likelihood ratios for a negative test result; and (2) Although the positive likelihood ratios are high and the positive predictive values low, the number of patients needed to be closely followed is 4:1 for the PlGF/sEng ratio and 3:1 for the slope of PlGF/sEng.

Changes in amniotic fluid concentration of thrombin-antithrombin III complexes in patients with preterm labor: evidence of an increased thrombin generation

OBJECTIVE

Preterm labor is associated with excessive maternal thrombin generation, as evidenced by increased circulating thrombin-antithrombin (TAT) III complexes concentration. In addition to its hemostatic functions, thrombin has uterotonic properties that may participate in the mechanism leading to preterm birth in cases of intrauterine bleeding. Thrombin also has a proinflammatory role, and inflammation is associated with increased thrombin generation. The aim of this study was to determine whether intra-amniotic infection/inflammation (IAI) is associated with increased amniotic fluid (AF) thrombin generation in women with preterm and term deliveries.

STUDY DESIGN

This cross-sectional study included the following groups: (1) mid-trimester (n = 74); (2) term not in labor (n = 39); (3) term in labor (n = 25); (4) term in labor with IAI (n = 22); (5) spontaneous preterm labor (PTL) who delivered at term (n = 62); (6) PTL without IAI who delivered preterm (n = 59); (7) PTL with IAI (n = 71). The AF TAT III complexes concentration was measured by enzyme linked immunosorbent assay (ELISA). Non-parametric statistics were used for analysis.

RESULTS

(1) TAT III complexes were identified in all AF samples; (2) patients with PTL who delivered preterm, with and without IAI, had a higher median AF TAT III complexes concentration than those with an episode of PTL who delivered at term (p < 0.001, p = 0.03, respectively); (3) among patients with PTL without IAI, elevated AF TAT III complexes concentration were independently associated with a shorter amniocentesis-to-delivery interval (hazard ratio, 1.5; 95% CI, 1.07-2.1); (4) among patients at term, those with IAI had a higher median AF TAT III complexes concentration than those without IAI, whether in labor or not in labor (p = 0.02); (5) there was no significant difference between the median AF TAT III complexes concentration of patients at term with and without labor; (6) patients who had a mid-trimester amniocentesis had a lower median AF TAT III complexes concentration than that of patients at term not in labor (p < 0.001).

CONCLUSIONS

We present herein a distinct difference in the pattern of intra-amniotic thrombin generation between term and preterm parturition. PTL leading to preterm delivery is associated with an increased intra-amniotic thrombin generation regardless of the presence of IAI. In contrast, term delivery is associated with an increased intra-amniotic thrombin generation only in patients with IAI.

Dysregulation of maternal serum adiponectin in preterm labor

OBJECTIVE

Intra-amniotic and systemic infection/inflammation have been causally linked to preterm parturition and fetal injury. An emerging theme is that adipose tissue can orchestrate a metabolic response to insults, but also an inflammatory response via the production of adipocytokines, and that these two phenomenons are interrelated. Adiponectin, an insulin-sensitising, anti-inflammatory adipocytokine, circulates in multimeric complexes including low-molecular weight (LMW) trimers, medium-molecular weight (MMW) hexamers and high-molecular weight (HMW) isoforms. Each of these complexes can exert differential biological effects. The aim of this study was to determine whether spontaneous preterm labor (PTL) with intact membranes and intra-amniotic infection/inflammation (IAI) is associated with changes in maternal serum circulating adiponectin multimers.

STUDY DESIGN

This cross-sectional study included patients in the following groups: (1) normal pregnant women (n=158); (2) patients with an episode of preterm labor and intact membranes without IAI who delivered at term (n=41); (3) preterm labor without IAI who delivered preterm (n=27); and (4) preterm labor with IAI who delivered preterm (n=36). Serum adiponectin multimers (total, HMW, MMW and LMW) concentrations were determined by ELISA. Non-parametric statistics were used for analyses.

RESULTS

(1) Preterm labor leading to preterm delivery or an episode of preterm labor that does not lead to preterm delivery was associated with a lower median maternal serum concentration of total and HMW adiponectin, a lower median HMW/total adiponectin ratio and a higher median LMW/total adiponectin ratio than normal pregnancy; (2) among patients with preterm labor, those with IAI had the lowest median concentration of total and HMW adiponectin, as well as the lowest median HMW/total adiponectin ratio; (3) the changes in maternal adiponectin and adiponectin multimers remained significant after adjusting for confounding factors such as maternal age, BMI, gestational age at sampling and parity.

CONCLUSION

(1) Preterm labor is characterised by a change in the profile of adiponectin multimers concentrations and their relative isoforms. These changes were observed in patients with an episode of preterm labor not leading to preterm delivery, in patients with intra-amniotic inflammation, or in those without evidence of intra-amniotic inflammation. (2) The changes in adiponectin multimer concentrations reported in preterm labor are different from those previously reported in spontaneous labor at term, suggesting that there is a fundamental difference between preterm labor and labor at term. (3) The findings reported herein provide the first evidence for the participation of adiponectin multimer in preterm parturition. We propose that adiponectins and adipokines in general provide a mechanism to organise the metabolic demands generated by the process of preterm parturition regardless of the nature of the insult (intra-amniotic inflammation or not).

Repeatability and reproducibility of fetal cardiac ventricular volume calculations using spatiotemporal image correlation and virtual organ computer-aided analysis

OBJECTIVE

The objective of this study was to quantify the repeatability and reproducibility of fetal cardiac ventricular volumes obtained using spatiotemporal image correlation (STIC) and Virtual Organ Computer-Aided Analysis (VOCAL; GE Healthcare, Kretztechnik, Zipf, Austria).

METHODS

A technique was developed to compute ventricular volumes using the subfeature Contour Finder: Trace. Twenty-five normal pregnancies were evaluated for the following: (1) to compare the coefficient of variation (CV) of ventricular volumes obtained using 15 degrees and 30 degrees rotation; (2) to compare the CV between 3 methods of quantifying ventricular volumes: (a) Manual Trace, (b) Inversion Mode, and (c) Contour Finder: Trace; and (3) to determine repeatability by calculating agreement and reliability of ventricular volumes when each STIC was measured twice by 3 observers. Reproducibility was assessed by obtaining 2 STICs from each of 44 normal pregnancies. For each STIC, 2 ventricular volume calculations were performed, and agreement and reliability were evaluated. Additionally, measurement error was examined.

RESULTS

(1) Agreement was better with 15 degrees rotation than 30 degrees (15 degrees: 3.6%; 95% confidence interval [CI], 3.0%-4.2%; versus 30 degrees: 7.1%; 95% CI, 5.8%-8.6%; P < .001); (2) ventricular volumes obtained with Contour Finder: Trace had better agreement than those obtained using either Inversion Mode (Contour Finder: Trace: 3.6%; 95% CI, 3.0%-4.2%; versus Inversion Mode: 6.0%; 95% CI, 4.9%-7.2%; P < .001) or Manual Trace (10.5%; 95% CI, 8.7%-12.5%; P < .001); (3) ventricular volumes were repeatable with good agreement and excellent reliability for both intraobserver and interobserver measurements; and (4) ventricular volumes were reproducible with negligible differences in agreement and good reliability. In addition, bias between STIC acquisitions was minimal (<1%; mean percent difference, -0.4%; 95% limits of agreement, -5.4%-5.9%).

CONCLUSIONS

Fetal echocardiography using STIC and VOCAL allows repeatable and reproducible calculation of ventricular volumes with the subfeature Contour Finder: Trace.

Antibiotic administration to patients with preterm premature rupture of membranes does not eradicate intra-amniotic infection

OBJECTIVE

Antibiotic administration has become part of the standard of care for patients with preterm premature rupture of membranes (PROM). Yet, the natural history of intrauterine infection/inflammation during antibiotic therapy remains largely unknown. This study was conducted to determine if antibiotic administration to the mother eradicates intra-amniotic infection and/or reduces the frequency of intra-amniotic inflammation, a risk factor for impending preterm labor/delivery and adverse neonatal outcome.

METHODS

A subset of patients with preterm PROM admitted to our institution underwent amniocenteses before and after antibiotic administration in order to guide clinical management. Amniotic fluid analysis consisted of a Gram stain, culture for aerobic and anaerobic bacteria as well as genital mycoplasmas, and amniotic fluid white blood cell (WBC) count. Microbial invasion of the amniotic cavity (MIAC) was defined as a positive amniotic fluid culture. Intra-amniotic inflammation was defined as an amniotic fluid WBC count >or=100/mm(3). Patients were given antibiotics and steroids after the 24(th) week of gestation. Antibiotic treatment consisted of ampicillin and erythromycin for 7 days for patients without evidence of intra-amniotic inflammation or MIAC, and ceftriaxone, clindamycin and erythromycin for 10-14 days for those with intra-amniotic inflammation or MIAC.

RESULTS

Forty-six patients with preterm PROM whose first amniocentesis was performed between 18 and 32 weeks (median 27.4 weeks) were included in the study. The overall prevalence of intra-amniotic inflammation in the first amniocentesis was 39% (18/46). Seven had a positive amniotic fluid culture for microorganisms. At the time of the second amniocentesis, six of the seven patients with a positive amniotic fluid culture had microorganisms. Of 18 patients with intra-amniotic inflammation at admission, only three showed no evidence of inflammation after antibiotic treatment. Among patients with no evidence of intra-amniotic inflammation at admission, 32% (9/28) developed inflammation despite therapy. Five of these nine patients had positive amniotic fluid cultures.

CONCLUSIONS

(1) Antibiotic administration (ceftriaxone, clindamycin, and erythromycin) rarely eradicates intra-amniotic infection in patients with preterm PROM; (2) intra-amniotic inflammation developed in one-third of patients who did not have inflammation at admission, despite antibiotic administration; (3) a sub-group of patients with documented inflammation of the amniotic cavity demonstrated a decrease in the intensity of the inflammatory process after antibiotic administration.

Four-dimensional fetal echocardiography with spatiotemporal image correlation (STIC): A systematic study of standard cardiac views assessed by different observers

OBJECTIVE

To test the agreement between observers and reproducibility of a technique to display standard cardiac views of the left and right ventricular outflow tracts from four-dimensional volume datasets acquired with Spatiotemporal Image Correlation (STIC).

METHODS

A technique was developed to obtain dynamic multiplanar images of the left ventricular outflow tract (LVOT) and right ventricular outflow tract (RVOT) from volume datasets acquired with STIC. Volume datasets were acquired from fetuses with normal cardiac anatomy. Twenty volume datasets of satisfactory quality were pre-selected by one investigator. The data was randomly assigned for a blinded review by two independent observers with previous experience in fetal echocardiography. Only one volume dataset was used for each fetus. After a training session, the observers obtained standardized cardiac views of the LVOT and RVOT, which were scored on a scale of 1 to 5, based on diagnostic value and image quality (1=unacceptable, 2=marginal, 3=acceptable, 4=good, and 5=excellent). Median scores and interquartile range, as well as inter- and intraobserver agreement were calculated for each view.

RESULTS

The mean menstrual age at the time of volume acquisition was 25.5+/-4.5 weeks. Median scores (interquartile range) for LVOT images, obtained by the first and second observers, were 3.5 (2.25-5.00) and 4 (3.00-5.00), respectively. The median scores (interquartile range) for RVOT images obtained by the first and second observers were 3 (3.00-5.00) and 3 (2.00-4.00), respectively. The interobserver intraclass correlation coefficient for the LVOT was 0.693 (95% CI 0.380-0.822), and 0.696 (95% CI 0.382-0.866) for the RVOT. For the intraobserver agreement analysis, observer 1 gave higher scores to the LVOT the second time the volumes were analyzed [LVOT: 3.50 (2.25-5.00) vs. 5.00 (4.00-5.00, p=0.008)].

CONCLUSION

STIC can be reproducibly used to evaluate fetal cardiac outflow tracts by independent examiners. Slightly better image quality rating scores during the intraobserver variability trial suggests the presence of a learning curve for the manipulation and analysis of volume data obtained by STIC.

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.

Plasma soluble vascular endothelial growth factor receptor-1 concentration is elevated prior to the clinical diagnosis of pre-eclampsia

OBJECTIVE

Accumulating evidence suggests that the balance between vascular endothelial growth factor (VEGF), placental growth factor (PIGF), and their receptors is important for effective vasculogenesis, angiogenesis, and placental development. Recently, the soluble form of VEGFR-1 (sVEGFR-1), an antagonist to VEGF and PIGF, has been implicated in the pathophysiology of pre-eclampsia. Plasma sVEGFR-1 concentration is elevated in pre-eclampsia at the time of clinical diagnosis and correlates with the severity of the disease. The purpose of this study was to determine whether the concentrations of sVEGFR-1 in plasma of pre-eclamptic patients change prior to the clinical manifestations of the disease.

METHODS

A longitudinal case-control study was conducted in normal pregnant women (n = 44) and patients with pre-eclampsia (n = 44). Blood sampling was performed at six intervals: (1) 7-16 weeks; (2) 16-24 weeks; (3) 24-28 weeks; (4)28-32 weeks; (5) 32-36 weeks; and (6) more than 37 weeks of gestation. To examine the relationship between plasmasVEGFR-1 concentration and interval to clinical diagnosis of pre-eclampsia, plasma samples of pre-eclamptic patients at different gestational ages were stratified according to the interval from blood sampling to clinical development of the disease into five groups: (1) at clinical manifestation; (2) 2-5 weeks; (3) 6-10 weeks; (4) 11-16 weeks; and (5) 17-25 weeks before clinical manifestations. Plasma concentrations of sVEGFR-1 were determined by enzyme-linked immunoassay. Parametric statistics and repeated measure procedures were used for the analysis.

RESULTS

The mean plasma sVEGFR-1 concentration in pre-eclamptic patients before the clinical manifestation of the disease was significantly higher than in normal pregnant women at 24-28, 28-32, and 32-37 weeks of gestation (p = 0.02,p < 0.001, and p < 0.001, respectively). In contrast, no significant differences in the mean plasma sVEGFR-1 concentration between patients with pre-eclampsia and normal pregnant women were observed both at 7-16 weeks and 16-24 weeks of gestation (p= 0.1 and p= 0.9). Similarly, the mean plasma sVEGFR-1 concentration was significantly higher in pre-eclamptic patients than in normal pregnant women at clinical manifestation, at 2-5 weeks (mean 3.8 weeks), and at 6-10 weeks (mean 8.2 weeks) prior to the development of clinical pre-eclampsia (p < 0.001, p < 0.001, and p = 0.002,respectively). Among patients with early-onset pre-eclampsia (defined as gestational age of 34 weeks or less), the mean plasma sVEGFR-1 concentration was significantly higher in pre-eclampsia (before clinical diagnosis) than in normal pregnant women at 24-28 (mean 26.4) weeks of gestation (p = 0.008). In contrast, among patients with the late-onset disease(defined as gestational age of more than 34 weeks), plasma sVEGFR-1 concentration in pre-clinical pre-eclampsia was significantly higher than in normal pregnant women at 28-32 (mean 30.2) weeks of gestation (p < 0.001).

CONCLUSIONS

Plasma sVEGFR-1 concentration is elevated in pre-eclampsia prior to the clinical diagnosis of the disease. This elevation began 6-10 weeks prior to the clinical manifestations, and the increase was more pronounced at 2-5 weeks before the diagnosis, as well as at clinical presentation. Furthermore, in early-onset pre-eclampsia, plasma concentration ofsVEGFR-1 is elevated earlier than the late-onset disease.

Maternal serum adiponectin multimers in gestational diabetes

OBJECTIVE

Adiponectin, an adipokine with profound insulin-sensitizing effect, consists of heterogeneous species of multimers. These oligomeric complexes circulate as low-molecular-weight (LMW) trimers, medium-molecular-weight (MMW) hexamers and high-molecular-weight (HMW) isoforms and can exert differential biological effects. The aims of this study were to determine whether there is a change in circulating adiponectin multimers in the presence of gestational diabetes mellitus (GDM), overweight/obesity or with a treatment with sulfonylurea or insulin in patients with GDM.

STUDY DESIGN

This cross-sectional study included women with: 1) normal pregnancy (n=149); and 2) patients with GDM (n=72). Thirty-three patients with GDM were managed with diet alone. Among the others 39 diabetic patients, 17 were treated with Glyburide and 22 with insulin. The study population was further stratified by first trimester body mass index (BMI) (normal weight <25 kg/m(2) vs. overweight/obese > or =25 kg/m(2)). Serum adiponectin multimers (total, HMW, MMW and LMW) concentrations were determined by ELISA.

RESULTS

1) The median maternal serum of total, HMW, MMW and LMW were lower in patients with GDM than in those with normal pregnancies (P<0.001 for all comparisons); 2) patients with GDM had a lower HMW/total adiponectin ratio and a higher MMW/total and LMW/total adiponectin ratio than those with a normal pregnancy (P<0.001 for all comparisons); and 3) among GDM patients, there were no differences in the concentrations and relative distribution of adiponectin multimers between those who were managed with diet, and those who were treated with pharmacological agents.

CONCLUSION

1) GDM is characterized by a distinctive pattern of concentrations and relative distribution of adiponectin multimers akin to Type 2 diabetes mellitus; 2) dysregulation of adiponectin multimeres can provide a mechanistic basis for the association between adiposity and GDM.

Amniotic fluid fetal hemoglobin in normal pregnancies and pregnancies complicated with preterm labor or prelabor rupture of membranes

OBJECTIVE

Hemoglobin and its catabolic products have been associated with amniotic fluid (AF) discoloration and intra-amniotic infection/inflammation (IAI). However, the origin of AF hemoglobin (maternal or fetal) has not been determined. The aims of this study were to determine if fetal hemoglobin can be detected in AF obtained from normal pregnancies, and whether there is an association between AF fetal hemoglobin concentrations and gestational age, spontaneous labor (term and preterm), preterm prelabor rupture of membranes (PPROM) and IAI.

STUDY DESIGN

This cross-sectional study included pregnant women in the following groups: (1) mid-trimester (n = 60); (2) term not in labor (n = 21); (3) term in labor (n = 47); (4) spontaneous preterm labor with intact membranes (PTL) without IAI who delivered at term (n = 89); (5) PTL without IAI who delivered preterm (n = 74); (6) PTL with IAI (n = 78); (7) PPROM with (n = 48) and (8) without IAI (n = 48). AF fetal hemoglobin concentrations were determined by ELISA. Non-parametric statistics were used for analyses.

RESULTS

(1) Fetal hemoglobin was detected in 80.4% of all AF samples; (2) women at term not in labor had a higher median AF fetal hemoglobin concentration than those at mid-trimester (p = 0.008); (3) labor at term was not associated with a significant difference in the median AF fetal hemoglobin concentration; (4) the median AF fetal hemoglobin concentration was not significantly different among the three PTL groups or between the PPROM groups; (5) women with PTL and IAI had a lower AF fetal hemoglobin percentage of the total hemoglobin than those without IAI who delivered preterm (p = 0.03) or at term (p < 0.001); (6) The median AF fetal hemoglobin concentration was higher in pregnancies complicated with PTL or PPROM than in women at term (p < 0.001 for all comparison).

CONCLUSIONS

(1) The concentration of immunoreactive AF fetal hemoglobin increases with gestational age; (2) the median AF fetal hemoglobin concentration is higher in pregnancies complicated with PTL or PPROM than in term pregnancies; (3) among women with PTL or PPROM, the AF fetal hemoglobin concentrations were not associated with IAI; (4) however, women with PTL and IAI had a lower percentage of AF fetal hemoglobin of the total hemoglobin than those without IAI, suggesting different mechanisms of disease.

Adiponectin multimers in maternal plasma

OBJECTIVE

Adiponectin is an anti-diabetic, anti-atherogenic, anti-inflammatory, and angiogenic adipokine that circulates in oligomeric complexes including: low molecular weight (LMW) trimers, medium molecular weight (MMW) hexamers, and high molecular weight (HMW) isoforms. The aim of this study was to determine whether there are changes in adiponectin multimers in pregnancy and as a function of maternal weight.

STUDY DESIGN

In this cross-sectional study, plasma concentrations of total, HMW, MMW, and LMW adiponectin were determined in women included in three groups: (1) normal pregnant women of normal body mass index (BMI) (n = 466), (2) overweight pregnant women (BMI >or=25; n = 257), and (3) non-pregnant women of normal weight (n = 40). Blood samples were collected once from each woman between 11 and 42 weeks of gestation. Plasma adiponectin multimer concentrations were determined by enzyme-linked immunosorbent assay (ELISA). Non-parametric statistics were used for analysis.

RESULTS

(1) The median HMW adiponectin concentration and the median HMW/total adiponectin ratio were significantly higher, and the median LMW adiponectin concentration was significantly lower in pregnant women than in non-pregnant women. (2) Among pregnant women, the median plasma concentration of total, HMW, and MMW adiponectin was significantly higher in normal weight women than in overweight patients. (3) Maternal HMW was the most prevalent adiponectin multimer regardless of gestational age or BMI status. (4) There were no significant differences in the median concentration of total, MMW, and LMW adiponectin and their relative distribution with advancing gestation.

CONCLUSION

Human pregnancy is characterized by quantitative and qualitative changes in adiponectin multimers, especially the most active isoform, HMW adiponectin.

Resistin in amniotic fluid and its association with intra-amniotic infection and inflammation

OBJECTIVE

Intra-amniotic infection/inflammation (IAI) is one of the most important mechanisms of disease in preterm birth. Resistin is an adipocytokine that has been linked to insulin resistance, diabetes, obesity and inflammation. The objective of this study was to determine if resistin is present in amniotic fluid (AF) and if its concentration changes with gestational age, in the presence of labour, and in IAI in patients with spontaneous preterm labour (PTL) and intact membranes, preterm prelabour rupture of membranes (PPROM) and clinical chorioamnionitis.

STUDY DESIGN

This cross-sectional study included 648 patients in the following groups: (1) women in the mid-trimester of pregnancy (14-18 weeks) who underwent amniocentesis for genetic indications and delivered a normal neonate at term (n = 61); (2) normal pregnant women at term with (n = 49) and without (n = 50) spontaneous labour; (3) patients with an episode of PTL and intact membranes who were classified into: (a) PTL who delivered at term (n = 153); (b) PTL who delivered preterm (<37 weeks gestation) without IAI (n = 108); and (c) PTL with IAI (n = 84); (4) women with PPROM with (n = 47) and without (n = 44) IAI; and (5) patients with clinical chorioamnionitis at term with (n = 22) and without (n = 30) microbial invasion of the amniotic cavity. Resistin concentration in AF was determined by enzyme-linked immunoassay. Non-parametric statistics were used for analyses.

RESULTS

(1) Resistin was detected in all AF samples; (2) the median AF resistin concentration at term was significantly higher than in the mid-trimester (23.6 ng/mL vs. 10 ng/mL; p < 0.001); (3) among patients with PTL, the median AF resistin concentration was significantly higher in patients with IAI than in those without IAI (144.9 ng/mL vs. 18.7 ng/mL; p < 0.001) and those with PTL and intact membranes who delivered at term (144.9 ng/mL vs. 16.3 ng/mL; p < 0.001); (4) patients with PPROM with IAI had a significantly higher median AF resistin concentration than those without IAI (132.6 ng/mL vs. 13 ng/mL; p < 0.001); (5) no significant differences were observed in the median AF resistin concentration between patients with spontaneous labour at term and those at term not in labour (28.7 ng/mL vs. 23.6 ng/mL; p = 0.07); and (6) AF resistin concentration > or =37 ng/mL (derived from a receiver-operating characteristic curve) had a sensitivity of 85.4% and a specificity of 94.3% for the diagnosis of intra-amniotic inflammation.

CONCLUSIONS

Resistin is a physiologic constituent of the AF, and its concentrations in AF: (1) are significantly elevated in the presence of IAI; (2) increase with advancing gestation; and (3) do not change in the presence of spontaneous labour at term. We propose that resistin may play a role in the innate immune response against intra-amniotic infection.

Tissue factor and its natural inhibitor in pre-eclampsia and SGA

OBJECTIVE

Tissue factor (TF), the major activator of the extrinsic pathway of coagulation, is abundant in the placenta and decidua. The aim of this study was to determine the maternal plasma concentrations of TF and its primary inhibitor, tissue factor pathway inhibitor (TFPI), in women who delivered small for gestational age (SGA) neonates, and in pre-eclampsia.

STUDY DESIGN

A cross-sectional study included the following groups: 1) women with normal pregnancies (n = 86); 2) patients who delivered SGA neonates (n = 61) and 3) women with pre-eclampsia (n = 133). Maternal plasma concentrations of TF and TFPI were measured by a sensitive immunoassay. Non-parametric statistics were used for analysis.

RESULTS

1) Women with pre-eclampsia had a significantly higher median plasma concentration of TF than patients with a normal pregnancy (median: 1187 pg/mL; range: 69-11675 vs. median: 291.5 pg/mL; range: 6.3-2662.2; p < 0.0001, respectively); 2) Similarly, TFPI concentrations were higher in pre-eclampsia than in normal pregnancy (median: 87.5 ng/mL; range 25.4-165.1 vs. median: 66.1 ng/mL; range: 14.3-86.5; p < 0.0001, respectively); 3) Surprisingly, mothers with SGA neonates had a lower median maternal plasma concentration of TF (median: 112.2 pg/mL; range: 25.6-1225.3) than women with a normal pregnancy (p < 0.0001).

CONCLUSION

1) Maternal plasma concentrations of TF in patients with pre-eclampsia, but not in those who delivered an SGA neonate, were higher than in women with normal pregnancies; 2) Although the role of immunoreactive plasma TF in coagulation remains controversial, our observations suggest that changes are present in the context of complications of pregnancy.

Evidence of the involvement of caspase-1 under physiologic and pathologic cellular stress during human pregnancy: a link between the inflammasome and parturition

OBJECTIVE

Caspase-1 is a component of the NALP3 inflammasome, a cytosolic multiprotein complex that mediates the processing of pro-inflammatory caspases and cytokines. The inflammasome represents the first line of defense against cellular stress and is a crucial component of innate immunity. Caspase-1 is the enzyme responsible for the cleavage and activation of interleukin (IL)-1 beta, which is a potent pro-inflammatory cytokine, and plays a central role in the mechanisms leading to labor (preterm and term) particularly in the context of intrauterine infection/inflammation. In addition, caspase-1 cleaves IL-18 and IL-33. The objectives of this study were to determine whether there is a relationship between amniotic fluid concentrations of caspase-1 and gestational age, parturition (term and preterm), and intra-amniotic infection/inflammation (IAI).

STUDY DESIGN

A cross-sectional study was conducted including 143 pregnant women in the following groups: (1) mid-trimester of pregnancy (n = 18); (2) term not in labor (n = 25); (3) term in labor (n = 28); (4) preterm labor (PTL) who delivered at term (n = 23); (5) PTL without IAI who delivered preterm (n = 32); (6) PTL with IAI who delivered preterm neonates (n = 17). Caspase-1 concentrations in amniotic fluid were determined by a specific and sensitive immunoassay. Non-parametric statistics were used for analysis.

RESULTS

(1) Caspase-1 was detected in amniotic fluid of women at term, but in none of the mid-trimester samples. (2) Patients in labor at term had a significantly higher median amniotic fluid concentration of caspase-1 than women at term not in labor (term in labor: 10.5 pg/mL, range 0.0-666.0 vs. term not in labor: 5.99 pg/mL, range 0.0-237.4; p < 0.05). (3) Among patients with spontaneous PTL, those with IAI (median 41.4 pg/mL, range 0.0-515.0) had a significantly higher median amniotic fluid caspase-1 concentration than those without IAI who delivered preterm (median 0.0 pg/mL, range 0.0-78.4) and than those who delivered at term (median 0.0 pg/mL, range 0.0-199.5); p < 0.001 for both comparisons.

CONCLUSIONS

(1) The presence and concentration of caspase-1 in the amniotic fluid varies as a function of gestational age. (2) Women with spontaneous labor at term had a higher median caspase-1 amniotic fluid concentration than women at term without labor. This suggests that the inflammasome may be activated in spontaneous parturition at term. Since most women with labor do not have intra-amniotic infection, we propose that cellular stress during labor accounts for activation of the inflammasome. (3) Preterm labor associated with infection/inflammation was also associated with a high concentration of caspase-1, suggesting that infection may induce caspase-1 production and activation of the inflammasome. (4) The sequential activation of the inflammasome and caspase-1, leading to interleukin-1 beta processing and secretion, is a candidate pathway leading to the activation of the common pathway of parturition.

Amniotic fluid concentration of surfactant proteins in intra-amniotic infection

OBJECTIVE

Pulmonary surfactant is a complex molecule of lipids and proteins synthesized and secreted by type II alveolar cells into the alveolar epithelial lining. Both lipid and protein components are essential for lung function in postnatal life. Infection is a well-established cause of preterm delivery, and several inflammatory cytokines play a role in the mechanisms of preterm parturition. An increased concentration of inflammatory cytokines in amniotic fluid or fetal plasma has been linked to the onset of preterm parturition and fetal/neonatal injury, including cerebral palsy and chronic lung disease. Experimental evidence indicates that inflammatory mediators also regulate surfactant protein synthesis, and histologic chorioamnionitis is associated with a decreased incidence of hyaline membrane disease in neonates. This study was conducted to determine if amniotic fluid concentrations of surfactant protein (SP)-A, SP-B, and SP-D change in patients with and without intra-amniotic infection (IAI).

MATERIALS AND METHODS

A case-control study was conducted to determine amniotic fluid concentrations of SP-A, SP-B, SP-D, and total protein in patients who had an amniocentesis performed between 18 and 34 weeks of gestation for the detection of IAI in patients with spontaneous preterm labor with intact membranes (n = 42) and cervical insufficiency prior to the application of cerclage (n = 6). Amniotic fluid samples were selected from a bank of biological specimens and included patients with (n = 16) and without (n = 32) IAI matched for gestational age at amniocentesis. Intra-amniotic infection was defined as a positive amniotic fluid culture for microorganisms. Each group was further subdivided according to a history of corticosteroid administration within 7 days prior to amniocentesis into the following subgroups: (1) patients without IAI who had received antenatal corticosteroids (n = 21), (2) patients with IAI who had received antenatal corticosteroids (n = 9), (3) patients without IAI who had not received antenatal corticosteroids (n = 11), and (4) patients with IAI who had not received antenatal corticosteroids (n = 7). Amniotic fluid was obtained by transabdominal amniocentesis. SP-A, SP-B, and SP-D concentrations in amniotic fluid were determined by enzyme-linked immunosorbent assay (ELISA). Non-parametric statistics were used for analysis.

RESULTS

Women with IAI had a higher median amniotic fluid concentration of SP-B and of SP-B/total protein, but not other SPs, than those without IAI (both p = 0.03). Among patients who had received antenatal corticosteroids, the median amniotic fluid concentration of SP-B and of SP-B/total protein was significantly higher in patients with IAI than in those without IAI (SP-B, IAI: median 148 ng/mL, range 37.3-809 ng/mL vs. without IAI: median 7.2 ng/mL, range 0-1035 ng/mL; p = 0.005 and SP-B/total protein, IAI: median 14.1 ng/mg, range 4.3-237.5 ng/mg vs. without IAI: median 1.45 ng/mg, range 0-79.5 ng/mg; p = 0.003). Among women who had not received antenatal corticosteroids, the median amniotic fluid concentrations of SP-B and of SP-B/total protein were not significantly different between patients with and without IAI (SP-B, IAI: median 4 ng/mL, range 0-31.4 ng/mL vs. without IAI: median 3.4 ng/mL, range 0-37 ng/mL; p = 0.8 and SP-B/total protein, IAI: median 0.55 ng/mg, range 0-6.96 ng/mg vs. without IAI: median 0.59 ng/mg, range 0-3.28 ng/mg; p = 0.9). The median amniotic fluid concentrations of SP-A, SP-A/total protein, SP-D, and SP-D/total protein were not significantly different between patients with and without IAI whether they received antenatal corticosteroids or not (all p > 0.05).

CONCLUSIONS

IAI was associated with an increased amniotic fluid concentration of SP-B in patients who received antenatal corticosteroids within 7 days prior to amniocentesis.

The concentration of surfactant protein-A in amniotic fluid decreases in spontaneous human parturition at term

OBJECTIVE

The fetus is thought to play a central role in the onset of labor. Pulmonary surfactant protein (SP)-A, secreted by the maturing fetal lung, has been implicated in the mechanisms initiating parturition in mice. The present study was conducted to determine whether amniotic fluid concentrations of SP-A and SP-B change during human parturition.

STUDY DESIGN

Amniotic fluid SP-A and SP-B concentrations were measured with a sensitive and specific ELISA in the following groups of pregnant women: (1) mid-trimester of pregnancy, between 15 and 18 weeks of gestation (n = 29), (2) term pregnancy not in labor (n = 28), and (3) term pregnancy in spontaneous labor (n = 26). Non-parametric statistics were used for analysis.

RESULTS

SP-A was detected in all amniotic fluid samples. SP-B was detected in 24.1% (7/29) of mid-trimester samples and in all samples at term. The median amniotic fluid concentrations of SP-A and SP-B were significantly higher in women at term than in women in the mid-trimester (SP-A term no labor: median 5.6 microg/mL, range 2.2-15.2 microg/mL vs. mid-trimester: median 1.64 microg/mL, range 0.1-4.7 microg/mL, and SP-B term no labor: median 0.54 microg/mL, range 0.17-1.99 microg/mL vs. mid-trimester: median 0 microg/mL, range 0-0.35 microg/mL; both p < 0.001). The median amniotic fluid SP-A concentration in women at term in labor was significantly lower than that in women at term not in labor (term in labor: median 2.7 microg/mL, range 1.2-10.1 microg/mL vs. term no labor: median 5.6 microg/mL, range 2.2-15.2 microg/mL; p < 0.001). There was no significant difference in the median amniotic fluid SP-B concentrations between women in labor and those not in labor (term in labor: median 0.47 microg/mL, range 0.04-1.32 microg/mL vs. term no labor: median 0.54 microg/mL, range 0.17-1.99 microg/mL; p = 0.2).

CONCLUSION

The amniotic fluid concentration of SP-A decreases in spontaneous human parturition at term.

Pyelonephritis during pregnancy: a cause for an acquired deficiency of protein Z

OBJECTIVE

Pyelonephritis has a more severe course during pregnancy than in the non-pregnant state. This has been attributed to the increased susceptibility of pregnant women to microbial products. An acquired protein Z deficiency has been reported when there is excessive thrombin activity. The aim of this study was to determine whether pyelonephritis during pregnancy is associated with changes in maternal plasma protein Z concentrations.

STUDY DESIGN

A cross-sectional study was conducted to compare plasma protein Z concentrations between normal pregnant women (N = 71) and pregnant women with pyelonephritis (N = 42). Protein Z concentrations were measured by enzyme-linked immunosorbent assay. Parametric and non-parametric statistics were used for analysis.

RESULTS

Patients with pyelonephritis had a significantly lower median plasma concentration of protein Z than did patients with normal pregnancies (median 2.14 microg/mL (0.4-3.4) vs. median 2.36 microg/mL (1.09-3.36); p = 0.03). There was no difference in the median plasma concentration of anti-protein Z antibodies between patients with pyelonephritis and those with normal pregnancies.

CONCLUSION

The median maternal plasma protein Z concentration was significantly lower in patients with pyelonephritis during pregnancy than in patients with normal pregnancies.