A mitochondrial regulator protein, MNRR1, is elevated in the maternal blood of women with preeclampsia

OBJECTIVE

Preeclampsia, one of the most serious obstetric complications, is a heterogenous disorder resulting from different pathologic processes. However, placental oxidative stress and an anti-angiogenic state play a crucial role. Mitochondria are a major source of cellular reactive oxygen species. Abnormalities in mitochondrial structures, proteins, and functions have been observed in the placentae of patients with preeclampsia, thus mitochondrial dysfunction has been implicated in the mechanism of the disease. Mitochondrial nuclear retrograde regulator 1 (MNRR1) is a newly characterized bi-organellar protein with pleiotropic functions. In the mitochondria, this protein regulates cytochrome c oxidase activity and reactive oxygen species production, whereas in the nucleus, it regulates the transcription of a number of genes including response to tissue hypoxia and inflammatory signals. Since MNRR1 expression changes in response to hypoxia and to an inflammatory signal, MNRR1 could be a part of mitochondrial dysfunction and involved in the pathologic process of preeclampsia. This study aimed to determine whether the plasma MNRR1 concentration of women with preeclampsia differed from that of normal pregnant women.

METHODS

This retrospective case-control study included 97 women with preeclampsia, stratified by gestational age at delivery into early (<34 weeks, n = 40) and late (≥34 weeks, n = 57) preeclampsia and by the presence or absence of placental lesions consistent with maternal vascular malperfusion (MVM), the histologic counterpart of an anti-angiogenic state. Women with an uncomplicated pregnancy at various gestational ages who delivered at term served as controls (n = 80) and were further stratified into early (n = 25) and late (n = 55) controls according to gestational age at venipuncture. Maternal plasma MNRR1 concentrations were determined by an enzyme-linked immunosorbent assay.

RESULTS

1) Women with preeclampsia at the time of diagnosis (either early or late disease) had a significantly higher median (interquartile range, IQR) plasma MNRR1 concentration than the controls [early preeclampsia: 1632 (924-2926) pg/mL vs. 630 (448-4002) pg/mL, p = .026, and late preeclampsia: 1833 (1441-5534) pg/mL vs. 910 (526-6178) pg/mL, p = .021]. Among women with early preeclampsia, those with MVM lesions in the placenta had the highest median (IQR) plasma MNRR1 concentration among the three groups [with MVM: 2066 (1070-3188) pg/mL vs. without MVM: 888 (812-1781) pg/mL, p = .03; and with MVM vs. control: 630 (448-4002) pg/mL, p = .04]. There was no significant difference in the median plasma MNRR1 concentration between women with early preeclampsia without MVM lesions and those with an uncomplicated pregnancy (p = .3). By contrast, women with late preeclampsia, regardless of MVM lesions, had a significantly higher median (IQR) plasma MNRR1 concentration than women in the control group [with MVM: 1609 (1392-3135) pg/mL vs. control: 910 (526-6178), p = .045; and without MVM: 2023 (1578-8936) pg/mL vs. control, p = .01].

CONCLUSIONS

MNRR1, a mitochondrial regulator protein, is elevated in the maternal plasma of women with preeclampsia (both early and late) at the time of diagnosis. These findings may reflect some degree of mitochondrial dysfunction, intravascular inflammation, or other unknown pathologic processes that characterize this obstetrical syndrome.

Successful multidisciplinary team management of placenta accreta spectrum disorder: A referral center model in a middle-income country

OBJECTIVE

The aim of the study was to evaluate the outcomes of placenta accreta spectrum (PAS) disorder managed by a multidisciplinary care team (MCT) compared with a conventional care team (CCT) in a PAS referral center in Thailand.

METHODS

This retrospective single-center cohort study analyzed PAS management outcomes in the PSU PAS Center between January 2010 and December 2022. The incidence of hemorrhage ≥3500 mL and the composite maternal and neonatal outcomes of PAS were compared before and after the introduction of an MCT in 2016.

RESULTS

Of 227 PAS cases, 219 (96.5%) had pathological confirmation. There were 52 (22.9%) cases of placenta accreta, 119 (52.4%) cases of placenta increta, and 56 (24.7%) cases of placenta percreta. The incidence of estimated blood loss (EBL) ≥3500 mL decreased from 61.8% to 34.3% (P < 0.001) after the establishment of the MCT. The median EBL decreased from 4000 (IQR: 2600,7250) mL to 2250 (1300, 4750) mL (P < 0.001). EBL reduction was statistically significant in the accreta and increta groups (P < 0.001). Red blood cell transfusions decreased from five (3, 9) to two (1, 6) units (P < 0.001) per patient. The length of maternal hospital stays and ICU admissions were statistically shorter when PAS was managed by an MCT (P < 0.001). The length of newborn hospital and ICU stays decreased significantly (P < 0.001).

CONCLUSION

The incidence of massive postpartum hemorrhage and a composite of maternal and neonatal morbidities in pregnant women with PAS disorder improved significantly after the establishment of an MCT to manage PAS in a middle-income country setting.

Clinical chorioamnionitis at term: definition, pathogenesis, microbiology, diagnosis, and treatment

Clinical chorioamnionitis, the most common infection-related diagnosis in labor and delivery units, is an antecedent of puerperal infection and neonatal sepsis. The condition is suspected when intrapartum fever is associated with two other maternal and fetal signs of local or systemic inflammation (eg, maternal tachycardia, uterine tenderness, maternal leukocytosis, malodorous vaginal discharge or amniotic fluid, and fetal tachycardia). Clinical chorioamnionitis is a syndrome caused by intraamniotic infection, sterile intraamniotic inflammation (inflammation without bacteria), or systemic maternal inflammation induced by epidural analgesia. In cases of uncertainty, a definitive diagnosis can be made by analyzing amniotic fluid with methods to detect bacteria (Gram stain, culture, or microbial nucleic acid) and inflammation (white blood cell count, glucose concentration, interleukin-6, interleukin-8, matrix metalloproteinase-8). The most common microorganisms are Ureaplasma species, and polymicrobial infections occur in 70% of cases. The fetal attack rate is low, and the rate of positive neonatal blood cultures ranges between 0.2% and 4%. Intrapartum antibiotic administration is the standard treatment to reduce neonatal sepsis. Treatment with ampicillin and gentamicin have been recommended by professional societies, although other antibiotic regimens, eg, cephalosporins, have been used. Given the importance of Ureaplasma species as a cause of intraamniotic infection, consideration needs to be given to the administration of antimicrobial agents effective against these microorganisms such as azithromycin or clarithromycin. We have used the combination of ceftriaxone, clarithromycin, and metronidazole, which has been shown to eradicate intraamniotic infection with microbiologic studies. Routine testing of neonates born to affected mothers for genital mycoplasmas could improve the detection of neonatal sepsis. Clinical chorioamnionitis is associated with decreased uterine activity, failure to progress in labor, and postpartum hemorrhage; however, clinical chorioamnionitis by itself is not an indication for cesarean delivery. Oxytocin is often administered for labor augmentation, and it is prudent to have uterotonic agents at hand to manage postpartum hemorrhage. Infants born to mothers with clinical chorioamnionitis near term are at risk for early-onset neonatal sepsis and for long-term disability such as cerebral palsy. A frontier is the noninvasive assessment of amniotic fluid to diagnose intraamniotic inflammation with a transcervical amniotic fluid collector and a rapid bedside test for IL-8 for patients with ruptured membranes. This approach promises to improve diagnostic accuracy and to provide a basis for antimicrobial administration.

Reliability of the sonographic evaluation for cervical length and elastography with pelvic parameters in term pregnancy by experienced operators with varying levels of experience

OBJECTIVE

To assess the reliability of sonographic measurements of six cervical and pelvic parameters by three sonographers with varying levels of experience.

METHODS

A cross-sectional study was conducted in pregnant women with a gestational age of ≥39 weeks. Each pregnant woman was examined by two sonographers with different levels of experience. Six parameters were measured: cervical length (CL), cervical strain elastography (extrinsic type), posterior cervical angle (PCA), fetal head-to-perineum distance (FHPD), fetal head-to-pubic symphysis distance (FHSD), and angle of progression (AOP). Intra- and interobserver reliabilities were assessed using the intraclass correlation coefficient with a 95% confidence interval. Pearson pairwise correlation coefficients were used to analyze the correlation between the parameter values.

RESULTS

In all, 66 pregnant women were enrolled in this study. We found excellent intraobserver reliability for measurements of CL, PCA, FHPD, FHSD, and AOP and good-to-excellent intraobserver reliability for cervical strain values in the cross-sectional view of the endocervix in the internal os area and cross-sectional view of the entire cervix in the internal os area. Interobserver reliability was excellent for all pelvic parameters, except for the FHPD. Strain values were moderate to excellent in the area of the internal os. A significant negative correlation between CL and strain values at the internal os was observed.

CONCLUSIONS

Pelvic parameters, except for FHPD, have excellent intra- and interobserver reliabilities. The high reproducibility of CL and cervical strain elastography at the internal os level, with a negative correlation between these two parameters, may play an important role in predicting successful induction of labor.

A biomarker for bacteremia in pregnant women with acute pyelonephritis: soluble suppressor of tumorigenicity 2 or sST2

Objective: Sepsis is a leading cause of maternal death, and its diagnosis during the golden hour is critical to improve survival. Acute pyelonephritis in pregnancy is a risk factor for obstetrical and medical complications, and it is a major cause of sepsis, as bacteremia complicates 15-20% of pyelonephritis episodes in pregnancy. The diagnosis of bacteremia currently relies on blood cultures, whereas a rapid test could allow timely management and improved outcomes. Soluble suppression of tumorigenicity 2 (sST2) was previously proposed as a biomarker for sepsis in non-pregnant adults and children. This study was designed to determine whether maternal plasma concentrations of sST2 in pregnant patients with pyelonephritis can help to identify those at risk for bacteremia.Study design: This cross-sectional study included women with normal pregnancy (n = 131) and pregnant women with acute pyelonephritis (n = 36). Acute pyelonephritis was diagnosed based on a combination of clinical findings and a positive urine culture. Patients were further classified according to the results of blood cultures into those with and without bacteremia. Plasma concentrations of sST2 were determined by a sensitive immunoassay. Non-parametric statistics were used for analysis.Results: The maternal plasma sST2 concentration increased with gestational age in normal pregnancies. Pregnant patients with acute pyelonephritis had a higher median (interquartile range) plasma sST2 concentration than those with a normal pregnancy [85 (47-239) ng/mL vs. 31 (14-52) ng/mL, p < .001]. Among patients with pyelonephritis, those with a positive blood culture had a median plasma concentration of sST2 higher than that of patients with a negative blood culture [258 (IQR: 75-305) ng/mL vs. 83 (IQR: 46-153) ng/mL; p = .03]. An elevated plasma concentration of sST2 ≥ 215 ng/mL had a sensitivity of 73% and a specificity of 95% (area under the receiver operating characteristic curve, 0.74; p = .003) with a positive likelihood ratio of 13.8 and a negative likelihood ratio of 0.3 for the identification of patients who had a positive blood culture.Conclusion: sST2 is a candidate biomarker to identify bacteremia in pregnant women with pyelonephritis. Rapid identification of these patients may optimize patient care.

Soluble suppression of tumorigenicity-2 in pregnancy with a small-for-gestational-age fetus and with preeclampsia

OBJECTIVE

Preeclampsia and fetal growth disorders are pregnancy-specific conditions that share common pathophysiological mechanisms. Yet, why some patients develop preeclampsia while others experience fetal growth restriction, or a combination of both clinical presentations, is unknown. We propose that the difference in severity of the maternal inflammatory response can contribute to the clinical phenotypes of preeclampsia vs. small for gestational age (SGA). To assess this hypothesis, we measured maternal plasma concentrations of the soluble isoform of suppression of tumorigenicity-2 (sST2), a member of the interleukin-1 receptor family that buffers proinflammatory responses. Previous reports showed that serum sST2 concentrations rise in the presence of intravascular inflammation and Th1-type immune responses and are significantly higher in patients with preeclampsia compared to those with normal pregnancy. The behavior of sST2 in pregnancies complicated by SGA has not been reported. This study was conducted to compare sST2 plasma concentrations in normal pregnancies, in those with preeclampsia, and in those with an SGA fetus.

METHODS

This retrospective cross-sectional study included women with an SGA fetus (n = 52), women with preeclampsia (n = 106), and those with normal pregnancy (n = 131). Maternal plasma concentrations of sST2 were determined by enzyme-linked immunosorbent assay. Doppler velocimetry of the uterine and umbilical arteries was available in a subset of patients with SGA (42 patients and 43 patients, respectively).

RESULTS

(1) Women with an SGA fetus had a significantly higher median plasma concentration of sST2 than normal pregnant women (p = .008); (2) women with preeclampsia had a significantly higher median plasma concentration of sST2 than those with normal pregnancy (p < .001) and those with an SGA fetus (p < .001); (3) patients with SGA and abnormal uterine artery Doppler velocimetry had a higher median plasma concentration of sST2 than controls (p < .01) and those with SGA and normal uterine artery Doppler velocimetry (p = .02); (4) there was no significant difference in the median plasma sST2 concentration between patients with SGA who had normal uterine artery Doppler velocimetry and controls (p = .4); (5) among patients with SGA, those with abnormal and those with normal umbilical artery Doppler velocimetry had higher median plasma sST2 concentrations than controls (p = .001 and p = .02, respectively); and (6) there was no significant difference in the median plasma sST2 concentrations between patients with SGA who did and those who did not have abnormal umbilical artery Doppler velocimetry (p = .06).

CONCLUSIONS

Preeclampsia and disorders of fetal growth are conditions characterized by intravascular inflammation, as reflected by maternal plasma concentrations of sST2. The severity of intravascular inflammation is highest in patients with preeclampsia.

Clinical chorioamnionitis at term is characterized by changes in the plasma concentration of CHCHD2/MNRR1, a mitochondrial protein

OBJECTIVE

Mitochondrial dysfunction was observed in acute systemic inflammatory conditions such as sepsis and might be involved in sepsis-induced multi-organ failure. Coiled-Coil-Helix-Coiled-Coil-Helix Domain Containing 2 (CHCHD2), also known as Mitochondrial Nuclear Retrograde Regulator 1 (MNRR1), a bi-organellar protein located in the mitochondria and the nucleus, is implicated in cell respiration, survival, and response to tissue hypoxia. Recently, the reduction of the cellular CHCHD2/MNRR1 protein, as part of mitochondrial dysfunction, has been shown to play a role in the amplification of inflammatory cytokines in a murine model of lipopolysaccharide-induced systemic inflammation. The aim of this study was to determine whether the plasma concentration of CHCHD2/MNRR1 changed during human normal pregnancy, spontaneous labor at term, and clinical chorioamnionitis at term.

METHODS

We conducted a cross-sectional study that included the following groups: 1) non-pregnant women (n = 17); 2) normal pregnant women at various gestational ages from the first trimester until term (n = 110); 3) women at term with spontaneous labor (n = 50); and 4) women with clinical chorioamnionitis at term in labor (n = 25). Plasma concentrations of CHCHD2/MNRR1 were assessed by an enzyme-linked immunosorbent assay.

RESULTS

1) Pregnant women at term in labor with clinical chorioamnionitis had a significantly higher plasma CHCHD2/MNRR1 concentration than those in labor without chorioamnionitis (p = .003); 2) CHCHD2/MNRR1 is present in the plasma of healthy non-pregnant and normal pregnant women without significant differences in its plasma concentrations between the two groups; 3) there was no correlation between maternal plasma CHCHD2/MNRR1 concentration and gestational age at venipuncture; and 4) plasma CHCHD2/MNRR1 concentration was not significantly different in women at term in spontaneous labor compared to those not in labor.

CONCLUSIONS

CHCHD2/MNRR1 is physiologically present in the plasma of healthy non-pregnant and normal pregnant women, and its concentration does not change with gestational age and parturition at term. However, plasma CHCHD2/MNRR1 is elevated in women at term with clinical chorioamnionitis. CHCHD2/MNRR1, a novel bi-organellar protein located in the mitochondria and the nucleus, is released into maternal plasma during systemic inflammation.

Evidence for the participation of CHCHD2/MNRR1, a mitochondrial protein, in spontaneous labor at term and in preterm labor with intra-amniotic infection

OBJECTIVE

Intra-amniotic inflammation (IAI), associated with either microbe (infection) or danger signals (sterile), plays a major role in the pathophysiology of preterm labor and delivery. Coiled-Coil-Helix-Coiled-Coil-Helix Domain Containing 2 (CHCHD2) [also known as Mitochondrial Nuclear Retrograde Regulator 1 (MNRR1)], a mitochondrial protein involved in oxidative phosphorylation and cell survival, is capable of sensing tissue hypoxia and inflammatory signaling. The ability to maintain an appropriate energy balance at the cellular level while adapting to environmental stress is essential for the survival of an organism. Mitochondrial dysfunction has been observed in acute systemic inflammatory conditions, such as sepsis, and is proposed to be involved in sepsis-induced multi-organ failure. The purpose of this study was to determine the amniotic fluid concentrations of CHCHD2/MNRR1 in pregnant women, women at term in labor, and those in preterm labor (PTL) with and without IAI.

METHODS

This cross-sectional study comprised patients allocated to the following groups: (1) mid-trimester (n = 16); (2) term in labor (n = 37); (3) term not in labor (n = 22); (4) PTL without IAI who delivered at term (n = 25); (5) PTL without IAI who delivered preterm (n = 47); and (6) PTL with IAI who delivered preterm (n = 53). Diagnosis of IAI (amniotic fluid interleukin-6 concentration ≥2.6 ng/mL) included cases associated with microbial invasion of the amniotic cavity and those of sterile nature (absence of detectable bacteria, using culture and molecular microbiology techniques). Amniotic fluid and maternal plasma CHCHD2/MNRR1 concentrations were determined with a validated and sensitive immunoassay.

RESULTS

(1) CHCHD2/MNRR1 was detectable in all amniotic fluid samples and women at term without labor had a higher amniotic fluid CHCHD2/MNRR1 concentration than those in the mid-trimester (p = 0.003); (2) the amniotic fluid concentration of CHCHD2/MNRR1 in women at term in labor was higher than that in women at term without labor (p = 0.01); (3) women with PTL and IAI had a higher amniotic fluid CHCHD2/MNRR1 concentration than those without IAI, either with preterm (p < 0.001) or term delivery (p = 0.01); (4) women with microbial-associated IAI had a higher amniotic fluid CHCHD2/MNRR1 concentration than those with sterile IAI (p < 0.001); (5) among women with PTL and IAI, the amniotic fluid concentration of CHCHD2/MNRR1 correlated with that of interleukin-6 (Spearman's Rho = 0.7; p < 0.001); and (6) no correlation was observed between amniotic fluid and maternal plasma CHCHD2/MNRR1 concentrations among women with PTL.

CONCLUSION

CHCHD2/MNRR1 is a physiological constituent of human amniotic fluid in normal pregnancy, and the amniotic concentration of this mitochondrial protein increases during pregnancy, labor at term, and preterm labor with intra-amniotic infection. Hence, CHCHD2/MNRR1 may be released into the amniotic cavity by dysfunctional mitochondria during microbial-associated IAI.

Maternal plasma syndecan-1: a biomarker for fetal growth restriction

OBJECTIVE

The identification of fetal growth disorders is an important clinical priority given that they increase the risk of perinatal morbidity and mortality as well as long-term diseases. A subset of small-for-gestational-age (SGA) infants are growth-restricted, and this condition is often attributed to placental insufficiency. Syndecan-1, a product of the degradation of the endothelial glycocalyx, has been proposed as a biomarker of endothelial damage in different pathologies. During pregnancy, a "specialized" form of the glycocalyx-the "syncytiotrophoblast glycocalyx"-covers the placental villi. The purpose of this study was to determine whether the concentration of maternal plasma syndecan-1 can be proposed as a biomarker for fetal growth restriction.

STUDY DESIGN

A cross-sectional study was designed to include women with normal pregnancy (n = 130) and pregnant women who delivered an SGA neonate (n = 50). Doppler velocimetry of the uterine and umbilical arteries was performed in women with an SGA fetus at the time of diagnosis. Venipuncture was performed within 48 h of Doppler velocimetry and plasma concentrations of syndecan-1 were determined by a specific and sensitive immunoassay.

RESULTS

(1) Plasma syndecan-1 concentration followed a nonlinear increase with gestational age in uncomplicated pregnancies (R² = 0.27, p < .001); (2) women with a pregnancy complicated with an SGA fetus had a significantly lower mean plasma concentration of syndecan-1 than those with an appropriate-for-gestational-age fetus (p = .0001); (3) this difference can be attributed to fetal growth restriction, as the mean plasma syndecan-1 concentration was significantly lower only in the group of women with an SGA fetus who had abnormal umbilical and uterine artery Doppler velocimetry compared to controls (p = .00071; adjusted p = .0028). A trend toward lower syndecan-1 concentrations was also noted for SGA with abnormal uterine but normal umbilical artery Doppler velocimetry (p = .0505; adjusted p = .067); 4) among women with an SGA fetus, those with abnormal umbilical and uterine artery Doppler findings had a lower mean plasma syndecan-1 concentration than women with normal Doppler velocimetry (p = .02; adjusted p = .04); 5) an inverse relationship was found between the maternal plasma syndecan-1 concentration and the umbilical artery pulsatility index (r = -0.5; p = .003); and 6) a plasma syndecan-1 concentration ≤ 850 ng/mL had a positive likelihood ratio of 4.4 and a negative likelihood ratio of 0.24 for the identification of a mother with an SGA fetus who had abnormal umbilical artery Doppler velocimetry (area under the ROC curve 0.83; p < .001).

CONCLUSION

Low maternal plasma syndecan-1 may reflect placental diseases and this protein could be a biomarker for fetal growth restriction. However, as a sole biomarker for this condition, its accuracy is low.

Acute pyelonephritis in pregnancy and plasma syndecan-1: evidence of glycocalyx involvement

BACKGROUND

Acute pyelonephritis, a risk factor for maternal sepsis, adult respiratory distress syndrome, and preterm labor, is a frequent cause of hospitalization. This condition is characterized by excessive intravascular inflammation and endothelial cell activation and dysfunction. Syndecan-1, a major component of the glycocalyx, is a gel-like layer that covers the luminal surface of healthy endothelial cells, preserving and mediating many endothelial functions. During pregnancy, there is an additional potential source of syndecan-1, the "syncytiotrophoblast glycocalyx," which lines the intervillous space. Insults that damage the glycocalyx lead to a shedding of syndecan-1 into the circulation. Hence, syndecan-1 has been proposed as a marker of endothelial injury in conditions such as sepsis, trauma, cardiovascular disease, and diabetes mellitus.

OBJECTIVE

The objective of this study was to determine whether the plasma syndecan-1 concentration changes in women with acute pyelonephritis in the presence or absence of bacteremia.

STUDY DESIGN

This cross-sectional study included three groups: (1) non-pregnant women (n = 25); (2) women with an uncomplicated pregnancy from whom samples were collected preterm (n = 61) or at term (n = 69); and (3) pregnant women diagnosed with acute pyelonephritis from whom samples were collected at the time of diagnosis during the second and third trimesters (n = 33). The diagnosis of acute pyelonephritis was based on clinical findings and a positive urine culture for bacteria. Blood culture results were available in 85% (28/33) of women with acute pyelonephritis. Plasma concentrations of syndecan-1 were determined by a validated immunoassay.

RESULTS

(1) Women with an uncomplicated pregnancy had a higher plasma concentration of syndecan-1 than non-pregnant women. The geometric mean (95% confidence interval [CI]) of syndecan-1 concentration was 51.0 (12.1-216.1) ng/mL in non-pregnant controls; 1280 (365-4487) ng/mL in normal preterm gestations; and 1786 (546-5834) ng/mL in normal term gestations (adjusted p < .005 for all three between group comparisons); (2) plasma syndecan-1 concentrations increased with gestational age among women with a normal pregnancy (p < .001, R² = 0.27); (3) syndecan-1 multiple of the mean (MoM) values in pregnant patients with acute pyelonephritis were higher than those in normal pregnant women based on second- and third-trimester samples (p = .048, 1.26-fold change). The increase was driven primarily by cases with a positive blood culture (p = .009, 1.74-fold change); (4) when data from third-trimester samples were compared, overall differences in syndecan-1 MoM values between cases and controls were slightly larger (p = .03, 1.36- fold change), which were especially contributed to by cases with a positive blood culture (p = .023, fold change 1.79-fold change).

CONCLUSIONS

Plasma syndecan-1 concentration is higher in pregnant women and increases as a function of gestational age. Patients with acute pyelonephritis have a higher plasma concentration of syndecan-1, and this is particularly the case in the presence of bacteremia.

Proteomic profile of extracellular vesicles in maternal plasma of women with fetal death

OBJECTIVES

Fetal death is a complication of pregnancy caused by multiple etiologies rather than being the end-result of a single disease process. Many soluble analytes in the maternal circulation, such as hormones and cytokines, have been implicated in its pathophysiology. However, changes in the protein content of extracellular vesicles (EVs), which could provide additional insight into the disease pathways of this obstetrical syndrome, have not been examined. This study aimed to characterize the proteomic profile of EVs in the plasma of pregnant women who experienced fetal death and to evaluate whether such a profile reflected the pathophysiological mechanisms of this obstetrical complication. Moreover, the proteomic results were compared to and integrated with those obtained from the soluble fraction of maternal plasma.

METHODS

This retrospective case-control study included 47 women who experienced fetal death and 94 matched, healthy, pregnant controls. Proteomic analysis of 82 proteins in the EVs and the soluble fractions of maternal plasma samples was conducted by using a bead-based, multiplexed immunoassay platform. Quantile regression analysis and random forest models were implemented to assess differences in the concentration of proteins in the EV and soluble fractions and to evaluate their combined discriminatory power between clinical groups. Hierarchical cluster analysis was applied to identify subgroups of fetal death cases with similar proteomic profiles. A p-value of <.05 was used to infer significance, unless multiple testing was involved, with the false discovery rate controlled at the 10% level (q < 0.1). All statistical analyses were performed by using the R statistical language and environment-and specialized packages.

RESULTS

Nineteen proteins (placental growth factor, macrophage migration inhibitory factor, endoglin, regulated upon activation normal T cell expressed and presumably secreted (RANTES), interleukin (IL)-6, macrophage inflammatory protein 1-alpha, urokinase plasminogen activator surface receptor, tissue factor pathway inhibitor, IL-8, E-Selectin, vascular endothelial growth factor receptor 2, pentraxin 3, IL-16, galectin-1, monocyte chemotactic protein 1, disintegrin and metalloproteinase domain-containing protein 12, insulin-like growth factor-binding protein 1, matrix metalloproteinase-1(MMP1), and CD163) were found to have different plasma concentrations (of an EV or a soluble fraction) in women with fetal death compared to controls. There was a similar pattern of change for the dysregulated proteins in the EV and soluble fractions and a positive correlation between the log₂-fold changes of proteins significant in either the EV or the soluble fraction (ρ = 0.89, p < .001). The combination of EV and soluble fraction proteins resulted in a good discriminatory model (area under the ROC curve, 82%; sensitivity, 57.5% at a 10% false-positive rate). Unsupervised clustering based on the proteins differentially expressed in either the EV or the soluble fraction of patients with fetal death relative to controls revealed three major clusters of patients.

CONCLUSION

Pregnant women with fetal death have different concentrations of 19 proteins in the EV and soluble fractions compared to controls, and the direction of changes in concentration was similar between fractions. The combination of EV and soluble protein concentrations revealed three different clusters of fetal death cases with distinct clinical and placental histopathological characteristics.

Are bacteria, fungi, and archaea present in the midtrimester amniotic fluid?

OBJECTIVES

This study was conducted to determine whether bacteria, fungi, or archaea are detected in the amniotic fluid of patients who underwent midtrimester amniocentesis for clinical indications.

METHODS

Amniotic fluid samples from 692 pregnancies were tested by using a combination of culture and end-point polymerase chain reaction (PCR) techniques. Intra-amniotic inflammation was defined as an interleukin-6 concentration >2,935 pg/mL.

RESULTS

Microorganisms were detected in 0.3% (2/692) of cases based on cultivation, 1.73% (12/692) based on broad-range end-point PCR, and 2% (14/692) based on the combination of both methods. However, most (13/14) of these cases did not have evidence of intra-amniotic inflammation and delivered at term. Therefore, a positive culture or end-point PCR in most patients appears to have no apparent clinical significance.

CONCLUSIONS

Amniotic fluid in the midtrimester of pregnancy generally does not contain bacteria, fungi, or archaea. Interpretation of amniotic fluid culture and molecular microbiologic results is aided by the assessment of the inflammatory state of the amniotic cavity. The presence of microorganisms, as determined by culture or a microbial signal in the absence of intra-amniotic inflammation, appears to be a benign condition.

Pregnancy-specific responses to COVID-19 revealed by high-throughput proteomics of human plasma

BACKGROUND

Pregnant women are at greater risk of adverse outcomes, including mortality, as well as obstetrical complications resulting from COVID-19. However, pregnancy-specific changes that underlie such worsened outcomes remain unclear.

METHODS

Plasma samples were collected from pregnant women and non-pregnant individuals (male and female) with (n = 72 pregnant, 52 non-pregnant) and without (n = 29 pregnant, 41 non-pregnant) COVID-19. COVID-19 patients were grouped as asymptomatic, mild, moderate, severe, or critically ill according to NIH classifications. Proteomic profiling of 7,288 analytes corresponding to 6,596 unique protein targets was performed using the SOMAmer platform.

RESULTS

Herein, we profile the plasma proteome of pregnant and non-pregnant COVID-19 patients and controls and show alterations that display a dose-response relationship with disease severity; yet, such proteomic perturbations are dampened during pregnancy. In both pregnant and non-pregnant state, the proteome response induced by COVID-19 shows enrichment of mediators implicated in cytokine storm, endothelial dysfunction, and angiogenesis. Shared and pregnancy-specific proteomic changes are identified: pregnant women display a tailored response that may protect the conceptus from heightened inflammation, while non-pregnant individuals display a stronger response to repel infection. Furthermore, the plasma proteome can accurately identify COVID-19 patients, even when asymptomatic or with mild symptoms.

CONCLUSION

This study represents the most comprehensive characterization of the plasma proteome of pregnant and non-pregnant COVID-19 patients. Our findings emphasize the distinct immune modulation between the non-pregnant and pregnant states, providing insight into the pathogenesis of COVID-19 as well as a potential explanation for the more severe outcomes observed in pregnant women.

Meconium-stained amniotic fluid

Green-stained amniotic fluid, often referred to as meconium-stained amniotic fluid, is present in 5% to 20% of patients in labor and has been traditionally considered an obstetrical hazard. Discolored amniotic fluid has been attributed to the presence of heme catabolic products from the passage of fetal colonic content (meconium), intraamniotic bleeding, or both. The frequency of green-stained amniotic fluid increases as a function of gestational age, reflecting maturation of the gastrointestinal system, and reaches approximately 27% in postterm gestation. Before the introduction of routine continuous fetal heart rate monitoring, green-stained amniotic fluid during labor was associated with fetal acidemia (umbilical artery pH <7.00), neonatal respiratory distress, and seizures, and was considered a risk factor for cerebral palsy. Hypoxia has been considered the main mechanism responsible for fetal defecation and meconium-stained amniotic fluid; however, most fetuses with meconium-stained amniotic fluid do not have fetal acidemia. Nonetheless, in the absence of fetal heart rate abnormalities, meconium-stained amniotic fluid is not associated with fetal acidemia. Intraamniotic infection/inflammation has emerged as an important factor in meconium-stained amniotic fluid in term and preterm gestations, and green-stained amniotic fluid is a risk factor for maternal and neonatal infections. Whether intraamniotic infection/inflammation results in discoloration of amniotic fluid via oxidative stress or the passage of meconium has not been determined. Two randomized clinical trials suggest that, in patients with meconium-stained amniotic fluid, intrapartum administration of antibiotics decreases the rate of clinical chorioamnionitis. Meconium aspiration syndrome is a severe complication typical of term newborns, which develops in 5% of cases presenting with meconium-stained amniotic fluid. Meconium aspiration syndrome is attributed to the mechanical and chemical effects of aspirated meconium coupled with local and systemic fetal inflammation. A systematic review of randomized controlled trials suggested that amnioinfusion may decrease the rate of meconium aspiration syndrome. Routine naso/oropharyngeal suctioning and tracheal intubation in cases of meconium-stained amniotic fluid have not been shown to be beneficial and are no longer recommended in obstetrical practice. Histologic staining of the membranes with meconium has been used in the context of medical legal litigation to attempt to time the occurrence of fetal injury. This has been largely based on the results of in vitro experiments. However, extrapolation of these findings to the clinical setting is unwarranted. Experimental studies in animals and observational studies in human fetuses suggest that fetal defecation is a physiological phenomenon throughout pregnancy.

Intra-amniotic inflammation in the mid-trimester of pregnancy is a risk factor for neuropsychological disorders in childhood

OBJECTIVES

Intra-amniotic inflammation is a subclinical condition frequently caused by either microbial invasion of the amniotic cavity or sterile inflammatory stimuli, e.g., alarmins. An accumulating body of evidence supports a role for maternal immune activation in the genesis of fetal neuroinflammation and the occurrence of neurodevelopmental disorders such as cerebral palsy, schizophrenia, and autism. The objective of this study was to determine whether fetal exposure to mid-trimester intra-amniotic inflammation is associated with neurodevelopmental disorders in children eight to 12 years of age.

METHODS

This is a retrospective case-control study comprising 20 children with evidence of prenatal exposure to intra-amniotic inflammation in the mid-trimester and 20 controls matched for gestational age at amniocentesis and at delivery. Amniotic fluid samples were tested for concentrations of interleukin-6 and C-X-C motif chemokine ligand 10, for bacteria by culture and molecular microbiologic methods as well as by polymerase chain reaction for eight viruses. Neuropsychological testing of children, performed by two experienced psychologists, assessed cognitive and behavioral domains. Neuropsychological dysfunction was defined as the presence of an abnormal score (<2 standard deviations) on at least two cognitive tasks.

RESULTS

Neuropsychological dysfunction was present in 45% (9/20) of children exposed to intra-amniotic inflammation but in only 10% (2/20) of those in the control group (p=0.03). The relative risk (RR) of neuropsychological dysfunction conferred by amniotic fluid inflammation remained significant after adjusting for gestational age at delivery [aRR=4.5 (1.07-16.7)]. Of the 11 children diagnosed with neuropsychological dysfunction, nine were delivered at term and eight of them had mothers with intra-amniotic inflammation. Children exposed to intra-amniotic inflammation were found to have abnormalities in neuropsychological tasks evaluating complex skills, e.g., auditory attention, executive functions, and social skills, whereas the domains of reasoning, language, and memory were not affected in the cases and controls.

CONCLUSIONS

Asymptomatic sterile intra-amniotic inflammation in the mid-trimester of pregnancy, followed by a term birth, can still confer to the offspring a substantial risk for neurodevelopmental disorders in childhood. Early recognition and treatment of maternal immune activation in pregnancy may be a strategy for the prevention of subsequent neurodevelopmental disorders in offspring.

Maternal plasma cytokines and the subsequent risk of uterine atony and postpartum hemorrhage

OBJECTIVES

To determine whether the maternal plasma concentrations of cytokines are higher in pregnant women with postpartum hemorrhage (PPH) compared to pregnant women without PPH.

METHODS

A retrospective case-control study included 36 women with PPH and 72 matched controls. Cases and controls were matched for gestational age at delivery, labor status, delivery route, parity, and year of sample collection. Maternal plasma samples were collected up to 3 days prior to delivery. Comparison of the plasma concentrations of 29 cytokines was performed by using linear mixed-effects models and included adjustment for covariates and multiple testing. A false discovery rate adjusted p-value <0.1 was used to infer significance. Random forest models with evaluation by leave-one-out and 9-fold cross-validation were used to assess the combined value of the proteins in predicting PPH.

RESULTS

Concentrations of interleukin (IL)-16, IL-6, IL-12/IL-23p40, monocyte chemotactic protein 1 (MCP-1), and IL-1β were significantly higher in PPH than in the control group. This difference remained significant after adjustment for maternal age, clinical chorioamnionitis, and preeclampsia. Multi-protein random forest proteomics models had moderate cross-validated accuracy for prediction of PPH [area under the ROC curve, 0.69 (0.58-0.81) by leave-one-out cross validation and 0.73 (0.65-0.81) by 9-fold cross-validation], and the inclusion of clinical and demographic information did not increase the prediction performance.

CONCLUSIONS

Pregnant women with severe PPH had higher median maternal plasma concentrations of IL-16, IL-6, IL-12/IL-23p40, MCP-1, and IL-1β than patients without PPH. These cytokines could serve as biomarkers or their pathways may be therapeutic targets.

Molecular subclasses of preeclampsia characterized by a longitudinal maternal proteomics study: distinct biomarkers, disease pathways and options for prevention

OBJECTIVES

The heterogeneous nature of preeclampsia is a major obstacle to early screening and prevention, and a molecular taxonomy of disease is needed. We have previously identified four subclasses of preeclampsia based on first-trimester plasma proteomic profiles. Herein, we expanded this approach by using a more comprehensive panel of proteins profiled in longitudinal samples.

METHODS

Proteomic data collected longitudinally from plasma samples of women who developed preeclampsia (n=109) and of controls (n=90) were available from our previous report on 1,125 proteins. Consensus clustering was performed to identify subgroups of patients with preeclampsia based on data from five gestational-age intervals by using select interval-specific features. Demographic, clinical, and proteomic differences among clusters were determined. Differentially abundant proteins were used to identify cluster-specific perturbed KEGG pathways.

RESULTS

Four molecular clusters with different clinical phenotypes were discovered by longitudinal proteomic profiling. Cluster 1 involves metabolic and prothrombotic changes with high rates of early-onset preeclampsia and small-for-gestational-age neonates; Cluster 2 includes maternal anti-fetal rejection mechanisms and recurrent preeclampsia cases; Cluster 3 is associated with extracellular matrix regulation and comprises cases of mostly mild, late-onset preeclampsia; and Cluster 4 is characterized by angiogenic imbalance and a high prevalence of early-onset disease.

CONCLUSIONS

This study is an independent validation and further refining of molecular subclasses of preeclampsia identified by a different proteomic platform and study population. The results lay the groundwork for novel diagnostic and personalized tools of prevention.

One-third of patients with eclampsia at term do not have an abnormal angiogenic profile

OBJECTIVES

An abnormal angiogenic profile is present in about one-half of women with preeclampsia at term. Few studies examined the roles of angiogenic biomarkers in eclampsia. The aims of this study were to determine (1) whether the degree of an anti-angiogenic state, reflected by a low placental growth factor (PlGF) to soluble fms-like tyrosine kinase-1 (sFlt-1) ratio, in women with eclampsia differed from that of women with severe preeclampsia; and (2) the prevalence of women who had an abnormal angiogenic profile at the diagnoses of preterm and term eclampsia.

METHODS

A cross-sectional study was conducted to include women in the following groups: (1) uncomplicated pregnancy (n=40); (2) severe preeclampsia (n=50); and (3) eclampsia (n=35). Maternal serum concentrations of PlGF and sFlt-1 were determined by immunoassays.

RESULTS

Women with preterm, but not term, eclampsia had a more severe anti-angiogenic state than those with severe preeclampsia (lower PlGF and PlGF/sFlt-1 ratio, each p<0.05). However, the difference diminished in magnitude with increasing gestational age (interaction, p=0.005). An abnormal angiogenic profile was present in 95% (19/20) of women with preterm eclampsia but in only 67% (10/15) of women with eclampsia at term.

CONCLUSIONS

Angiogenic biomarkers can be used for risk assessment of preterm eclampsia. By contrast, a normal profile of angiogenic biomarkers cannot reliably exclude patients at risk for eclampsia at term. This observation has major clinical implications given that angiogenic biomarkers are frequently used in the triage area as a test to rule out preeclampsia.

Rapid diagnosis of intra-amniotic infection using nanopore-based sequencing

OBJECTIVES

Early diagnosis and treatment of intra-amniotic infection is crucial. Rapid pathogen identification allows for a definite diagnosis and enables proper management. We determined whether the 16S amplicon sequencing performed by a nanopore sequencing technique make possible rapid bacterial identification at the species level in intra-amniotic infection.

METHODS

Five cases of confirmed intra-amniotic infection, determined by either cultivation or 16S rDNA polymerase chain reaction (PCR) Sanger sequencing, and 10 cases of women who underwent mid-trimester genetic amniocentesis were included. DNA was extracted from amniotic fluid and PCR was performed on the full-length 16S rDNA. Nanopore sequencing was performed. The results derived from nanopore sequencing were compared with those derived from cultivation and Sanger sequencing methods.

RESULTS

Bacteria were successfully detected from amniotic fluid using nanopore sequencing in all cases of intra-amniotic infection. Nanopore sequencing identified additional bacterial species and polymicrobial infections. All patients who underwent a mid-trimester amniocentesis had negative cultures, negative 16S PCR Sanger sequencing and nanopore sequencing. Identification of the microorganisms using nanopore sequencing technique at the bacterial species level was achieved within 5-9 h from DNA extraction.

CONCLUSIONS

This is the first study demonstrating that the nanopore sequencing technique is capable of rapid diagnosis of intra-amniotic infection using fresh amniotic fluid samples.

The role of intraamniotic inflammation in threatened midtrimester miscarriage

BACKGROUND

The assessment and management of patients with threatened midtrimester miscarriage is a clinical challenge because the etiology of this condition is poorly understood.

OBJECTIVE

This study aimed to examine the frequency of intraamniotic infection or inflammation and the effect of antibiotics in patients presenting with regular uterine contractions and intact membranes before 20 weeks of gestation.

STUDY DESIGN

This retrospective study comprised patients who met the following criteria: (1) singleton gestation, (2) gestational age before 20 weeks, (3) the presence of regular uterine contractions confirmed by a tocodynamometer (8 or more contractions in 60 minutes), (4) intact amniotic membranes, and (5) transabdominal amniocentesis performed for the evaluation of the microbiologic and inflammatory status of the amniotic cavity. Samples of amniotic fluid were cultured for aerobic and anaerobic bacteria and genital mycoplasmas, and polymerase chain reaction was performed to detect Ureaplasma species. Amniotic fluid was tested for white blood cell counts and matrix metalloproteinase-8 concentrations to diagnose intraamniotic inflammation. Patients with intraamniotic inflammation, or intraamniotic infection, were treated with antibiotics (a combination of ceftriaxone, clarithromycin, and metronidazole). Treatment success was defined as the resolution of intraamniotic infection/inflammation at the follow-up amniocentesis or delivery after 34 weeks of gestation.

RESULTS

1) Intraamniotic inflammation was present in 88% (15/17) of patients, whereas infection was detectable in only 2 cases; 2) objective evidence of resolution of intraamniotic inflammation after antibiotic treatment was demonstrated in 100% (4/4) of patients who underwent a follow-up amniocentesis; 3) 30% (5/15) of women receiving antibiotics delivered after 34 weeks of gestation (3 of the 5 patients had a negative follow-up amniocentesis, and 2 of the women were without a follow-up amniocentesis); 4) the overall treatment success of antibiotics was 40% (6/15; 4 cases of objective evidence of resolution of intra-amniotic inflammation and 5 cases of delivery after 34 weeks of gestation).

CONCLUSION

The prevalence of intraamniotic inflammation in patients who presented with a threatened midtrimester miscarriage was 88% (15/17), and, in most cases, microorganisms could not be detected. Antibiotic treatment, administered to patients with intraamniotic inflammation, was associated with either objective resolution of intraamniotic inflammation or delivery after 34 weeks of gestation in 40% (6/15) of the cases.

Characterization of amniotic fluid sludge in preterm and term gestations

OBJECTIVE

To describe the characteristics of amniotic fluid sludge obtained from patients in term and preterm gestations.

METHODS

This cross-sectional study included patients with dense aggregates of particulate matter detected in amniotic fluid, observed with transvaginal sonography. All patients were in labor and had an impending delivery, either preterm or at term. Echogenic material contained within amniotic fluid was retrieved transvaginally by needle amniotomy under direct visualization. The amniotic fluid analysis consisted of a Gram stain, cultures for aerobic/anaerobic bacteria and genital mycoplasmas, and a white blood cell count.

RESULTS

Twenty-five patients ranging from 18 to 41 weeks of gestation were included in the study. We observed the following: (1) the appearance of amniotic fluid was consistent with pus-like material, vernix, or meconium by naked eye examination; (2) samples collected before 33 weeks of gestation (n = 13) had a pus-like appearance; however, after this gestational age, most of the samples [83% (10/12)] appeared to be consistent with vernix; (3) amniotic fluid cultures were positive for microorganisms in 13 patients, of which 10 were preterm gestations before 33 weeks; (4) the most frequent microorganisms retrieved by culture were genital mycoplasmas (Ureaplasma urealyticum [46% (6/13)]), followed by Mycoplasma hominis [31% (4/13)] and Candida albicans [15% (2/13)]; and (5) patients with sonographic particulate matter in preterm gestations frequently presented acute histologic chorioamnionitis and funisitis, but these conditions were rare in patients at term.

CONCLUSION

The nature of amniotic fluid particulate material varies as a function of gestational age. The material obtained in preterm gestations is frequently related to an inflammatory process, while that obtained at term is often consistent with vernix and appears to represent a maturational process.

Fetal sepsis: a cause of stillbirth

Infection is considered a leading cause of fetal death, responsible for approximately 20% of cases. Such estimates are derived from the frequency of acute histological chorioamnionitis and funisitis in cases of fetal death rather than direct detection of microorganisms in the fetal compartment. We report a case of clinically unexplained fetal death at 38 weeks of gestation in an uncomplicated pregnancy resulting in delivery of an appropriate-for-gestational-age fetus. The mother did not have any clinical signs of infection. Overwhelming bacterial invasion in multiple fetal organs, including the heart, liver, spleen, and kidneys, was observed despite the lack of evidence of maternal clinical infection. The bacteria were visualized by using standard histologic techniques (e.g. H&E/ tissue Gram stain) highlighting the value of autopsy in determining the cause of death.

Perturbations in kinetics of the thrombin generation assay identify women at risk of preeclampsia in the first trimester and provide the rationale for a preventive approach

BACKGROUND

Activation of the coagulation system and increased thrombin generation have been implicated in the pathophysiology of preeclampsia, and this rationale supports the administration of low-molecular-weight heparin to prevent this syndrome in patients at risk. Yet, randomized trials of this prophylactic measure have yielded contradictory results. A possible explanation is that only a subset of patients with preeclampsia have excessive thrombin generation and would benefit from the administration of low-molecular-weight heparin. Therefore, the key questions are whether and when patients who subsequently develop preeclampsia present evidence of abnormal thrombin generation.

OBJECTIVE

This study aimed to determine (1) the kinetics of thrombin generation throughout gestation in women with a normal pregnancy and in those with early and late preeclampsia, and (2) the diagnostic performance of in vivo thrombin generation parameters to predict the development of preeclampsia.

STUDY DESIGN

This retrospective, nested case-control study was based on a prospective longitudinal cohort of singleton gestations. Cases comprised women who developed preeclampsia (n=49), and controls consisted of patients with a normal pregnancy (n=45). Preeclampsia was classified into early-onset (n=24) and late-onset (n=25). Longitudinal changes in the parameters of the thrombin generation assay (lag time, time to peak thrombin concentration, peak thrombin concentration, endogenous thrombin generation, and velocity index) throughout gestation were compared between the study groups, and normal pregnancy percentiles were derived from the control group. We tested whether a single parameter or a combination of parameters, derived from the kinetics of thrombin generation, could identify patients who subsequently developed preeclampsia. Time-related parameters <10th percentile were considered short, and concentration-related parameters >90^th percentile were considered high.

RESULTS

(1) Patients who developed preeclampsia (early- and late-onset) had abnormal thrombin generation kinetics as early as 8 to 16 weeks of pregnancy; (2) patients with a combination of a short lag time and high peak thrombin concentration at 8 to 16 weeks of pregnancy had an odds ratio of 43.87 for the subsequent development of preeclampsia (area under the curve, 0.79; sensitivity, 56.8%; specificity, 92.7%; positive likelihood ratio, 7.76); (3) at 16 to 22 weeks of gestation, patients with a combination of a short lag time and a high velocity index had an odds ratio of 16 for the subsequent development of preeclampsia (area under the curve, 0.78; sensitivity, 62.2%; specificity, 92.5%; positive likelihood ratio, 8.29).

CONCLUSION

During early pregnancy, the thrombin generation assay can identify the subset of patients at a greater risk for the development of preeclampsia owing to accelerated and enhanced production of thrombin. This observation provides a rationale for testing the efficacy of low-molecular-weight heparin in this subset of patients. We propose that future research on the efficacy of low-molecular-weight heparin and other interventions targeting the coagulation system to prevent preeclampsia should be focused on patients with abnormal kinetics of thrombin generation.

Persistent reversed end-diastolic flow of the middle cerebral artery: A rare and concerning finding

Fetal reversed end-diastolic flow of the middle cerebral artery is a rare ultrasound finding associated with pathological fetal conditions. Herein, we report the case of a fetus presenting with reversed end-diastolic flow of the middle cerebral artery caused by extensive intracranial hemorrhage from maternal warfarin therapy. From a literature review, we present the clinical findings, etiologies, and outcomes of cases with fetal reversed end-diastolic flow of the middle cerebral artery.

Pregnancy-specific responses to COVID-19 are revealed by high-throughput proteomics of human plasma

Pregnant women are at greater risk of adverse outcomes, including mortality, as well as obstetrical complications resulting from COVID-19. However, pregnancy-specific changes that underlie such worsened outcomes remain unclear. Herein, we profiled the plasma proteome of pregnant and non-pregnant COVID-19 patients and controls and showed alterations that display a dose-response relationship with disease severity; yet, such proteomic perturbations are dampened during pregnancy. In both pregnant and non-pregnant state, the proteome response induced by COVID-19 showed enrichment of mediators implicated in cytokine storm, endothelial dysfunction, and angiogenesis. Shared and pregnancy-specific proteomic changes were identified: pregnant women display a tailored response that may protect the conceptus from heightened inflammation, while non-pregnant individuals display a stronger response to repel infection. Furthermore, the plasma proteome can accurately identify COVID-19 patients, even when asymptomatic or with mild symptoms. This study represents the most comprehensive characterization of the plasma proteome of pregnant and non-pregnant COVID-19 patients.

The role of the placenta in spontaneous preterm labor and delivery with intact membranes

OBJECTIVES

To determine whether placental vascular pathology and impaired placental exchange due to maturational defects are involved in the etiology of spontaneous preterm labor and delivery in cases without histologic acute chorioamnionitis.

METHODS

This was a retrospective, observational study. Cases included pregnancies that resulted in spontaneous preterm labor and delivery (<37 weeks), whereas uncomplicated pregnancies that delivered fetuses at term (≥37-42 weeks of gestation) were selected as controls. Placental histological diagnoses were classified into three groups: lesions of maternal vascular malperfusion, lesions of fetal vascular malperfusion, and placental microvasculopathy, and the frequency of each type of lesion in cases and controls was compared. Moreover, we specifically searched for villous maturational abnormalities in cases and controls. Doppler velocimetry of the umbilical and uterine arteries were performed in a subset of patients.

RESULTS

There were 184 cases and 2471 controls, of which 95 and 1178 had Doppler studies, respectively. The frequency of lesions of maternal vascular malperfusion was greater in the placentas of patients with preterm labor than in the control group [14.1% (26/184) vs. 8.8% (217/2471) (p=0.023)]. Disorders of villous maturation were more frequent in the group with preterm labor than in the control group: 41.1% (39/95) [delayed villous maturation in 31.6% (30/95) vs. 2.5% (13/519) in controls and accelerated villous maturation in 9.5% (9/95) vs. none in controls].

CONCLUSIONS

Maturational defects of placental villi were associated with approximately 41% of cases of unexplained spontaneous preterm labor and delivery without acute inflammatory lesions of the placenta and with delivery of appropriate-for-gestational-age fetuses.

Low-dose aspirin for prevention of preeclampsia: Implementation of the NICE guideline in Thailand

AIM

To evaluate the effectiveness of a preeclampsia (PE) screening program using the National Institute for Health and Care Excellence (NICE) guideline in pregnant Thai women.

METHODS

A total of 2552 pregnancies received antenatal care and were delivered at Songklanagarind Hospital between November 2016 and April 2020. PE screening with the NICE guideline was used to identify mothers at risk. In cases of positive screening results, a daily dose of 81 mg aspirin was prescribed. Pregnancy outcomes were compared with 2783 participants who had maternity care before the implementation of the screening program. The effectiveness of aspirin prophylaxis following the NICE guideline was assessed by a logistic regression model to compare the risk of PE development between before and after guidance.

RESULTS

The screening positive rate by NICE was 8.3%. Of these, 77.36% of the participants received aspirin prophylaxis according to the NICE recommendation. After the implementation of the PE screening program, the incidence of PE slightly decreased (from 4.31% to 3.72%, p = 0.274). The chance of PE in pregnancies who had high-risk factors was reduced after using low-dose aspirin prophylaxis, even though the difference was not statistically significant.

CONCLUSIONS

Screening with the NICE guidelines followed by prescription of low-dose aspirin (81 mg/day) was probably not an effective strategy for the prevention of PE in our population. Combining biophysical and biochemical markers to identify pregnant women who subsequently develop PE, concurrently with an increased dose of aspirin prophylaxis, may provide a better outcome in clinical practice.

Relationship of anthropometric measurements with glycated hemoglobin and 1-h blood glucose after 50 g glucose challenge test in pregnant women: A longitudinal cohort study in Southern Thailand

AIMS

To assess correlations of anthropometric measurements with glycated hemoglobin (HbA1c) and 1-h blood glucose after a 50 g glucose challenge test during the first and late second trimesters and explore their relationships of anthropometric measurements with neonatal birth weight.

METHODS

A longitudinal study was conducted among pregnant Thai women with gestational age ≤14 weeks. Anthropometric measurements, using body mass index, body compositions, and circumferences, and skinfold thickness, were measured at four-time points: ≤14, 18-22, 24-28, and 30-34 weeks of gestation. HbA1c and 1-h blood glucose were examined at ≤14 and 24-28 weeks. Neonatal birth weight was recorded.

RESULTS

Of 312 women, HbA1c was more correlated with anthropometric measurements during pregnancy than 1-h blood glucose. At 24-28 weeks, women with high/very high body fat percentage were more likely to have higher HbA1c. Women with high subscapular skinfold thickness were more likely to have higher 1-h blood glucose at ≤14 and 24-28 weeks. High hip circumference significantly increased neonatal birth weights.

CONCLUSION

Anthropometric measurements were longitudinally correlated with HbA1c and 1-h blood glucose, higher in the late second than first trimesters, as well as neonatal birth weight. The mechanisms to explain the relationship of different anthropometric measurements are required to be further studied.

Utility of fetal facial markers on a second trimester genetic sonogram in screening for Down syndrome in a high-risk Thai population

Background

To establish the reference ranges and evaluate the efficacy of the fetal facial sonomarkers prenasal thickness (PT), nasal bone length (NBL), PT/NBL ratio and NBL/PT ratio for Down syndrome screening in the second trimester of high-risk pregnancies using two-dimensional (2D) ultrasound.

Methods

A prospective study was done in Thai pregnant women at high risk for structural and chromosomal abnormalities between May 2018 and May 2019. The main exclusion criteria were any fetal anatomical anomaly detected on ultrasonography or postpartum examination, abnormal chromosome or syndrome other than Down syndrome. Ultrasounds were performed in 375 pregnant women at 14 to 22 weeks’ gestation and the fetal facial parameters were analyzed. Down syndrome results were confirmed by karyotyping. The reference ranges of these facial ultrasound markers were constructed based on the data of our population. The Down syndrome screening performance using these facial ultrasound markers was evaluated.

Results

In total, 340 euploid fetuses and 11 fetuses with Down syndrome met the inclusion criteria. The PT, NBL, and PT/NBL ratios in the euploid fetuses gradually increased with gestation progression while the NBL/PT ratio gradually decreased between 14–22 weeks’ gestation. The NBL, PT/NBL ratio, and NBL/PT ratio all had 100% sensitivity and PT had 91% sensitivity. These facial markers had 100% negative predictive value for Down syndrome screening in the second trimester. The Bland–Altman analysis showed the intra- and inter-observer variations of PT and NBL had high intraclass correlation coefficients (ICC) in both operators, with ICCs of 0.98 and 0.99 and inter-observer ICCs of 0.99 for both operators.

Conclusion

The facial ultrasound markers are very useful for second trimester Down syndrome screening in our population. These facial ultrasound markers were easily identifiable and highly consistent either intra- or inter-operator by using widely-available 2D ultrasound. However, the reference ranges for these markers need to be constructed based on individual populations.

Trial registration

Registration number: REC 61–029-12–3. Date of registration: 18 May 2018.

A new risk score model to predict preeclampsia using maternal factors and mean arterial pressure in early pregnancy

The purpose of this study was to establish a multivariable risk-scoring model for preeclampsia (PE) prediction based on maternal characteristics and mean arterial pressure (MAP). Multivariate logistic regression analysis from 4600 pregnancies during a 10-year period was used to create the best fitting model. Significant risk factors and weighted scores consisted of age ≥30 years (3), BMI ≥25 kg/m² (2), multifetal pregnancy (9), history of PE (9), adverse perinatal outcomes (6), pregnancy interval >10 years (5), nulliparous (5), underlying renal disease (10), chronic hypertension (6), autoimmune disease (5), diabetes (2) and MAP ≥95 mmHg (5). The model achieved an ROC area 0.771 with detection rates of 34%, 44%, 53% and 58% at 5%, 10%, 15% and 20% fixed false-positive rates, respectively. The new risk score model could be a clinically useful screening tool for PE. Pregnant women who have total scores of 9-13 (high risk) and more than 14 (very high risk) should receive aspirin prophylaxis.Impact StatementWhat is already known on this subject? Preeclampsia (PE) is the major cause of maternal and perinatal mortality and morbidity; it can be prevented by antiplatelet agents.What the results of this study add? A new model for identifying maternal at risk for PE using clinical risk factors and MAP was created. Weighted scores were defined for each variable for easy use in clinical practice. According to their probability for PE, pregnant women were classified into three subgroups: low risk (score 0-8), high risk (score 9-13) and very high risk groups (score ≥ 14). Aspirin should be prescribed to high risk and very high risk groups. For safety concerns, very high risk pregnancies should have close antenatal surveillance in a tertiary care hospital to reduce adverse outcomes during pregnancy and childbirth.What the implications are of these findings for clinical practice and/or further research? This new model for identifying pregnant women at high risk for PE has the potential to reduce the morbidity and mortality associated with this disease.

Ethnic-specific reference range affects the efficacy of quadruple test as a universal screening for Down syndrome in a developing country

Objective

To evaluate the efficacy of the quadruple test for potential use as a Thai national policy for Down syndrome (DS) screening and establish an accurate equation for risk estimation of Down syndrome based on gestational age, weight and the ethnic-specific reference range of our population.

Methods

A prospective study was conducted on singleton pregnancies at 14 to 21 weeks of gestation to evaluate the efficacy of quadruple DS screening using the automatically calculated Western European descent factor (WF) in our population and the impact of screening using a specific Thai ethnic factor as well as to establish an equation for the risk estimation of DS based on gestational age, weight and a local Thai ethnic factor to correct for the impact of ethnic factor on the screening efficacy.

Results

Of a total of 5,515 women, 12 cases of DS and 8 cases of other aneuploidies were found. The detection rate, false positive rate and specificity were 75.0%, 9.1% and 90.9%, respectively, by automatic calculation with the widely used WF; the screening efficacy was lower when used in Asian populations than in other studies. The best-fitted regression equation of serum quadruple screening of AFP, free β-hCG, uE3 and inhibin A was established by adjustment for gestational age (GA) in days, maternal weight and our Thai-specific ethnic reference range which was created for this study. Calculations with our Thai-specific ethnic model gave a better detection rate of 83.3%, a false positive rate of 9.6% and specificity of 90.4%.

Conclusion

The serum quadruple test had a lower detection rate than expected when the risk estimation was based on the WF reference range. The serum quadruple test using WF had significantly different levels when corrected with our ethnic-specific factor. Using our local ethnic specific model could increase the detection rate of DS screening in Thailand with a minimal increase in false positive rates. Our findings indicate that DS screening should be adjusted with an appropriate individual ethnic factor when used for national screening.

Correlations of spot urinary sodium and potassium with blood pressure in pregnant women: A longitudinal study in Southern Thailand

OBJECTIVE

To assess the changes of spot urinary sodium and potassium and blood pressure (BP) throughout pregnancy and their correlations in southern Thailand.

METHODS

A longitudinal study was conducted in southern Thailand from March 2018 to November 2019. Spot urinary excretion of sodium per creatinine (U[Na⁺ ]/[Cr]), potassium per creatinine (U[K⁺ ]/[Cr]) and U[Na⁺ ]/[K⁺ ] ratios, and BP were measured at four time points throughout pregnancy. A one-way analysis of variance with repeated measures and Bonferroni correction with post hoc analysis was used to identify significant differences between time points. The correlations were measured using Pearson's correlation coefficients.

RESULTS

A total of 327 pregnant women were included. Both systolic and diastolic BPs decreased gradually from up to 14 weeks of pregnancy to 18-22 weeks and then increased until 30-34 weeks. Mean spot U[Na⁺ ]/[Cr] ratios did not significantly change during the study period. Mean spot U[K⁺ ]/[Cr] ratios gradually increased, and spot U[Na⁺ ]/[K⁺ ] ratios gradually decreased. The correlation of spot U[Na⁺ ]/[Cr] and U[K⁺ ]/[Cr] ratios with BPs was weakly negative at all four time points.

CONCLUSIONS

Spot U[Na⁺ ]/[Cr] and U[K⁺ ]/[Cr] ratios are inversely correlated with BPs; weak correlations are found among pregnant women in southern Thailand. Further research in different populations is required to confirm its correlation and broader use.

Screening for pre-eclampsia: Performance of National Institute for Health and Care Excellence guidelines versus American College of Obstetricians and Gynecologists recommendations

AIM

The purpose of this study was to compare the accuracy of the National Institute for Health and Care Excellence (NICE) guidelines and the American College of Obstetricians and Gynecologists (ACOG) recommendations for pre-eclampsia (PE) screening.

METHODS

This retrospective study included 4600 Thai pregnant women who received maternity care between January 2006 and December 2015 at Songklanagarind Hospital, a tertiary care center in southern Thailand. The medical data of each participant were assessed using the NICE and ACOG criteria to identify maternal risk for PE. The sensitivity, specificity, positive likelihood ratio and negative likelihood ratio for detecting pregnancies complicated with PE according to each guideline were calculated. Receiver operating characteristic (ROC) curves were constructed to compare the predictive performance.

RESULTS

Pre-eclampsia was found in 167 cases (3.63%). The ACOG recommendations achieved ROC area 0.70 (58.1% sensitivity with 82.4% specificity) for PE at any gestation and ROC area 0.66 (62.9% sensitivity with 69.0% specificity) for PE which required delivery before 37 weeks' gestation. ROC areas based on the NICE guidelines were 0.64 (35.3% sensitivity with 92.5% specificity) and 0.59 (34.8% sensitivity with 83.4% specificity) for all PE and preterm PE, respectively. The ACOG criteria were significantly more accurate than the NICE criteria for detecting maternal risk for all PE, preterm PE and nulliparity cases (P values <0.05).

CONCLUSION

For Thai pregnant women, screening for PE with maternal risk factors according to the ACOG recommendations was more effective in identifying high-risk pregnancies than the NICE guidelines.

Time Interval Measurements of the Ductus Venosus During the Early Second Trimester of Pregnancy: Reference Ranges and Clinical Application

OBJECTIVES

The aims of this study were to construct reference ranges for the time interval parameters of the ductus venosus during the early second trimester of pregnancy and to demonstrate the clinical utility in various fetal disorders.

METHODS

The ductus venosus Doppler measurements of 331 healthy fetuses between 15 and 22 weeks' gestation were analyzed. The systolic time and diastolic time were subdivided into the systolic acceleration time, systolic deceleration time, diastolic acceleration time, and diastolic deceleration time. The median, 5th, and 95th regression lines for each variable were determined according to gestational age. The ductus venosus time interval parameters in cases of fetoplacental abnormalities were calculated and plotted against the reference ranges.

RESULTS

With advancing gestation, the systolic acceleration time and total systolic time increased significantly (P < .001). In contrast to the systolic phase, the diastolic deceleration time decreased significantly during the early second trimester of pregnancy (P = .023). The systolic deceleration time, diastolic acceleration time, and diastolic time were relatively constant. Fetuses with tricuspid insufficiency, twin-twin transfusion syndrome, intrauterine fetal growth restriction, and anemia had abnormal ductus venosus times with different patterns.

CONCLUSIONS

Predicted normal reference ranges for time interval variables in relation to gestational age were established. These could be helpful for assessing fetal cardiovascular function during the early second trimester of pregnancy.

Accuracy of Ultrasonography Performed by Thai Maternal Fetal Medicine Fellowship at Songklanagarind Hospital for Fetal Sex Determination during Second Trimester Genetic Amniocentesis

OBJECTIVE

To evaluate the accuracy of fetal sex determination using ultrasonography performed by Thai Maternal Fetal Medicine fellowships during second trimester genetic amniocentesis and also identify the possible factors of inaccurate determination.

MATERIAL AND METHOD

A prospective non-random study was conducted to evaluate the accuracy of fetal sex determination using ultrasonography performed by Thai Maternal Fetal Medicine fellows at Songklanagarind Hospital during second trimester genetic amniocentesis and also identify the possible factors of inaccurate determination.

RESULTS

Five hundred and sixty singleton pregnant women were enrolled. Eight cases were excluded due to abnormal fetal karyotype. No pregnancy loss or fetal ambiguous genitalia presented. The sex of 11/552 (1.99%) fetuses could not be adequately determined by ultrasonography. Overall, 491 of the 541 diagnose were correct – an accuracy of 90.8% (CI 88.0- 93.1) given an ultrasonographic diagnosis could be made. Among phenotypic females, the accuracy was 226/246, (91.9%; 95% CI 87.7-95.0) and among phenotypic males, the accuracy was 265/295 (89.8%; 95% CI 85.2-92.4). The ultrasonographic diagnosis of female sex was correct in 226/256, (88.3%; 95% CI 84.0-92.0), and the ultrasonographic diagnosis of male sex was correct in 265/285, (93.0%; 95% CI 89.4-95.7). For both sexes combined and for female fetuses, year of fellowship was only significant variable associated with correct sex determination by ultrasonography [2nd year vs. 1st year: overall ORS 2.55, (95% CI 1.44-4.61); female fetuses ORS 6.54, (95% CI 2.48-17.26)].

CONCLUSION

Fetal sex determination using ultrasonography by Thai Maternal Fetal Medicine Fellows at Songklanagarind Hospital during second trimester genetic amniocentesis is possible. Less experienced physicians should be had increased awareness especially in case of female external genitalia diagnosis.

Ductus venosus blood flow velocity waveforms during the early second trimester of pregnancy in a Thai population

OBJECTIVE

To establish reference ranges for ductus venosus (DV) blood flow velocities and indices during the early second trimester.

METHODS

A cross-sectional DV Doppler study of fetuses at 15-22 weeks of gestation was conducted at Songklanagarind Hospital, Songkhla, Thailand, during 2013-2014. The peak forward velocities were recorded and the DV indices were calculated. Predicted reference ranges based on the 5th and 95th percentiles according to the week of gestation were constructed.

RESULTS

Among 371 fetuses, measurement of DV Doppler waveforms in the sagittal plane was achieved in 97.5% of cases. With advancing pregnancy (weeks 15 to 22), the DV velocities during ventricular systole, early diastole, and atrial contraction increased from 47.48 cm/s to 68.22 cm/s, 42.23 cm/s to 60.52 cm/s, and 15.94 cm/s to 34.84 cm/s, respectively. The time-averaged maximum value increased from 37.61 cm/s to 55.42 cm/s. The DV indices-pulsatility index for the vein, peak velocity index for the vein, preload index, and systolic/a-wave ratio-decreased from 0.79 to 0.59, 0.71 to 0.53, 0.63 to 0.47, and 2.72 to 1.90, respectively. The systolic/diastolic ratio remained relatively constant at 1.12.

CONCLUSIONS

Normal reference ranges for DV flow velocities and indices during the early second trimester were established.

Incidence of fetal bradycardia and effect of placental injury on fetal heart rate during second-trimester genetic amniocentesis

A prospective study was conducted for comparing the incidence of fetal bradycardia and level of fetal heart rate change following a second-trimester genetic amniocentesis with and without placental injury. A total of 257 and 495 participants in injured and non-injured groups were analysed. The incidence of fetal bradycardia following amniocentesis was not statistically different between the two groups (1.17%, [95% CI 0.24, 3.37] and 0.20%, [95% CI 0.005, 1.12]) in injured and non-injured placenta groups, respectively; p = 0.118). The mean change in baseline fetal heart rate before and after amniocentesis was also not significantly different between the two groups (p = 0.844). No fetal death or pregnancy loss occurred within 4 weeks after the procedure. All 4 bradycardia participants were normal and healthy and had an appropriate weight for their gestational age. We conclude that placental injury during a second-trimester genetic amniocentesis due to advanced maternal age poses only a low risk of fetal bradycardia, and there is no evidence of differences between subjects with injured and non-injured placenta in the changes in fetal heart rate.