Toward a new taxonomy of obstetrical disease: improved performance of maternal blood biomarkers for the great obstetrical syndromes when classified according to placental pathology

Mapping genetic susceptibility to spontaneous preterm birth: analysis of Utah pedigrees to find inherited genetic factors

BACKGROUND

Spontaneous preterm birth (SPTB) is the leading cause of neonatal morbidity and mortality. It is a final common pathway for multiple etiologies, some of which are well known while others likely remain to be identified. Despite recent advancements in identifying genetic risk factors, the mechanisms of many SPTBs remain poorly understood due to the phenotypic heterogeneity and complexity. Large family-based studies decrease heterogeneity and improve power to identify genetic causes of SPTB.

OBJECTIVE

To identify inherited genetic factors in SPTB etiology using large families.

STUDY DESIGN

Using the Utah Population Database, which links a 4.5 million-person genealogy to state birth certificate and fetal death records, we identified large pedigrees containing multiple women with early SPTB (<34 weeks' gestation) and any SPTB (<37 weeks' gestation). We reviewed birth certificate data to exclude those with maternal and fetal diagnoses associated with iatrogenic preterm birth, resulting in 74 large multiplex pedigrees for early SPTB. Enrolled women with SPTB underwent comprehensive clinical phenotyping with review of primary medical records. Seven pedigrees, each containing at least 3 sampled women with SPTB, were the focus of this genetic study. High-density single-nucleotide polymorphism genotyping was conducted in maternal peripheral blood samples from women in the seven pedigrees. Shared genomic segments analysis was performed to identify genome-wide significant chromosomal regions shared in excess by women with SPTB.

RESULTS

We identified two genome-wide significant chromosomal regions. In single-pedigree SGS analysis, a 1.75 Mega base region in chromosome 8 (8q24.23) was shared by 5 out of 6 women with SPTB in a single large pedigree (false positive rate=0.028). In duo-pedigree analysis, a 1.05 Mega base region in the same 8q24.23 locus was identified in a second pedigree (false-positive rate [duo]=0.0019). The intersecting region at the 8q24.23 locus contains FAM135B (family with sequence similarity 135 member B) and KHDRBS3 (KH RNA-binding domain containing, signal transduction associated 3) genes, which have previously been implicated in oncogenesis and ovarian cancer, respectively. Duo-pedigree SPTB analysis also identified a second genome-wide significant 67 kilo base locus in chromosome 12 (12q21.1-q21.2) that was shared by all women with SPTB in two independent pedigrees (false-positive rate [duo]=0.01). The intersecting region at the 12q21.1-q21.2 locus contains CAPS2 (calcyphosine 2) and KCNC2 (potassium voltage-gated channel subfamily C member 2) genes, both implicated in vascular-related complications of pregnancy and preterm labor.

CONCLUSION

Using large SPTB families, we identified shared chromosomal regions (8q24.23 and 12q21.1-q21.2), providing evidence for inherited (segregating) risk loci in SPTB etiology. Further investigation into genes in SPTB etiology, including functional validation may provide avenues for novel therapeutic development and guide efforts for SPTB prevention to prolong pregnancy and improve outcomes.

Placental and Umbilical Cord Anomalies Detected by Ultrasound as Clinical Risk Factors of Adverse Perinatal Outcomes. Case Series Review of Selected Conditions. Part 3: Vascular Anomalies of the Umbilical Cord and Fetoplacental Vascular Malperfusion

In the previous published reviews Part 1 and Part 2, we examined the association between placental and umbilical cord anomalies in relation to adverse perinatal outcomes. In this conclusive Part 3, only umbilical cord vascular anomalies are considered, together with the perinatal effects caused by maternal vascular malperfusion and the secondary fetal vascular malperfusion anomalies. Specifically, the review comprises the following umbilical cord pathologies: umbilical cord torsion/stricture, amniotic band syndrome and umbilical cord strictures/strangulation, umbilical cord hemorrhagic cyst, umbilical cord rupture/cord hemangioma, umbilical cord hematoma, and umbilical cord ulceration. A series of case presentations and a gallery of images have been included to illustrate this final review.

Time to reconcile the dichotomy of the cardiovascular-placental axis

Linked article: This Editorial comments on the article by Nan et al. Click here to view the article.

Soluble fms-like tyrosine kinase-1/placental growth factor ratio at 36 weeks' gestation: association with spontaneous onset of labor and intrapartum fetal compromise in low-risk pregnancies

BACKGROUND

Previous evidence showed that placental dysfunction triggers spontaneous preterm or term births and intrapartum fetal compromise and often requires urgent delivery, thereby exposing both the fetus and the mother to significant risks. Predicting spontaneous labor onset and intrapartum fetal compromise could improve obstetrical management and outcomes, but this is currently difficult, particularly in low-risk populations.

OBJECTIVE

The objective of this study was to examine whether placental dysfunction, as assessed at 36 weeks' gestation by the soluble fms-like tyrosine kinase-1 to placental growth factor ratio, is associated with the interval to spontaneous onset of labor and intrapartum fetal compromise that requires cesarean delivery in a routinely examined population.

STUDY DESIGN

This was a retrospective analysis of prospectively collected data of women with singleton pregnancies who underwent routine assessment at 35+0 to 36+6 weeks' gestation at the King's College Hospital (London, England). Using a general linear model, the study examined the outcomes related to the soluble fms-like tyrosine kinase-1/placental growth factor ratio, including the time interval from testing to spontaneous onset of labor and the subsequent rate of fetal compromise that required a cesarean delivery. Patients who underwent induction of labor or prelabor cesarean deliveries were excluded from the study. Competing risks regression and Cox regression models were used to estimate the cumulative incidence and the risk of the outcomes of interest.

RESULTS

In the screened population of 45,375 patients, 23,831 (52.5%) had spontaneous onset of labor and were included in the analysis. Cases with an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 delivered about 1 week earlier than those with a ratio of ≤50 (39.2 vs 40.0 weeks' gestation; P<.001). The general linear model showed that a larger soluble fms-like tyrosine kinase-1/placental growth factor ratio was associated with earlier spontaneous onset of labor (P<.001), particularly among multiparous women. The soluble fms-like tyrosine kinase-1/placental growth factor ratio was significantly associated, as expected, with cases of preeclampsia and advanced maternal age. The cumulative incidence of spontaneous onset of labor was significantly higher in cases with an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 than in those with a ratio 50 (P<.001). Cox regression showed that the risk for spontaneous onset of labor increased with an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 (hazard ratio, 1.424; 95% confidence interval, 1.253-1.618; P<.001) and, as expected, the risk was mitigated over time from when the soluble fms-like tyrosine kinase-1/placental growth factor ratio was measured to spontaneous labor onset (P<.001). Cases with intrapartum fetal compromise had a higher mean soluble fms-like tyrosine kinase-1/placental growth factor ratio than those without intrapartum fetal compromise (21.79 vs 17.67; P<.001). Qualitative addition of fetal compromise to the general linear model showed a higher soluble fms-like tyrosine kinase-1/placental growth factor ratio in cases with fetal compromise than in those without fetal compromise (P=.014). Competing risks regression showed a positive dose-response effect for fetal compromise with increasing soluble fms-like tyrosine kinase-1/placental growth factor ratios (P<.001). Above and below the optimal cutoff of 50, the quoted cumulative incidences were 6.7% and 4.7%, respectively (P<.001). The effect of the soluble fms-like tyrosine kinase-1/placental growth factor ratio remained significant even after adjusting for preeclampsia, which is a well-known major risk factor for fetal compromise. Finally, the proportion of cases with intrapartum fetal compromise who had an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 decreased from 35% to 0% with advancing gestation.

CONCLUSION

This study showed that an increased soluble fms-like tyrosine kinase-1/placental growth factor ratio at 36 weeks' gestation is associated with an earlier gestational age at spontaneous onset of labor and higher rates of intrapartum fetal compromise. There are 2 major implications, namely an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 indicates imminent labor onset with about a 40% mean risk increase and immediate clinical translation for term pregnancy monitoring. In addition, an increased soluble fms-like tyrosine kinase-1/placental growth factor ratio increases the risk for intrapartum fetal compromise, although outcome variability indicates reassessment within multimarker models.

The Predictive Value of Soluble Fms-Like Tyrosine Kinase-1 for Prognosis in COVID-19 Patients

Background

Coronavirus Disease 2019 (COVID-19), caused by the novel coronavirus, has posed a significant threat to global public health, leading to substantial morbidity, mortality, and strain on healthcare resources. Despite the availability of vaccines and treatments, effective biomarkers for predicting disease progression remain limited. This study aimed to investigate the prognostic value of soluble fms-like tyrosine kinase-1 (sFlt-1) in COVID-19 patients.

Methods

A prospective cohort study was conducted involving 154 COVID-19 patients, with comprehensive clinical data and laboratory parameters analyzed to evaluate the effectiveness of sFlt-1 in determining disease severity and prognosis.

Results

The results revealed that sFlt-1 levels correlated significantly with disease severity, showing higher levels in severe/critical cases compared to mild cases (P<0.05). In the deceased group, sFlt-1 levels were notably higher compared to survivors, with an area under the curve (AUC) of 0.840, showing good predictive power for 28-day mortality. Multivariable logistic regression identified sFlt-1, respiratory rate, and albumin as independent prognostic factors, with a combined AUC of 0.938 (95% CI: 0.886-0.991) for predicting mortality risk.

Conclusion

These findings underscore the potential of sFlt-1 as a valuable biomarker for clinical decision-making in managing COVID-19 patients. Future studies should focus on the clinical application of sFlt-1 and explore its underlying mechanisms to enhance patient management strategies.

The rapid diagnosis of intraamniotic infection with nanopore sequencing

BACKGROUND

Intraamniotic infection (defined as intraamniotic inflammation with microorganisms) is an important cause of the preterm labor syndrome. Methods for the detection of microorganisms in amniotic fluid are culture and/or polymerase chain reaction assay. However, both methods take time, and the results are rarely available for clinical decision-making. Nanopore sequencing technology offers real-time, long-read sequencing that can produce rapid results.

OBJECTIVE

To determine 1) the diagnostic performance of the 16S rDNA nanopore sequencing method for the identification of microorganisms in patients with intraamniotic inflammation and 2) the relationship between microbial burden and the intensity of the amniotic fluid inflammatory response.

STUDY DESIGN

We performed a prospective cohort study that included singleton pregnancies presenting with symptoms of preterm labor with intact membranes or of preterm prelabor rupture of the membranes. Amniotic fluid samples were obtained for the evaluation of bacteria in the amniotic cavity using cultivation and polymerase chain reaction-based 16S Sanger sequencing methods. Participants were classified into 4 groups according to the results of an amniotic fluid culture, 16S Sanger sequencing, and an amniotic fluid interleukin 6 concentration: 1) no intraamniotic infection and intraamniotic inflammation (interleukin 6 <2.6 ng/mL, and no microorganisms in the amniotic cavity, as determined by culture or 16S Sanger sequencing); 2) microbial invasion of the amniotic cavity without intraamniotic inflammation, defined by the presence of bacteria detected by culture or 16S Sanger sequencing; 3) sterile intraamniotic inflammation (interleukin 6 ≥2.6 ng/mL without microbial invasion of the amniotic cavity); and 4) intraamniotic infection (interkeukin 6 ≥2.6 ng/mL with microbial invasion of the amniotic cavity). Patients who underwent a mid-trimester amniocentesis, had no intraamniotic infection or intraamniotic inflammation, and delivered at term represented the control group. 16S rDNA nanopore sequencing was performed and the diagnostic indices for the identification of intraamniotic infection were determined. Bioinformatic analysis was carried out to identify microorganisms, and a read count of at least 100 or a read count exceeding that of the background species from the control group, along with a relative abundance of no less than 1%, was used.

RESULTS

1) The 16S nanopore sequencing had a sensitivity of 88.9% (8/9), specificity of 95.4% (41/43), positive predictive value of 80.0% (8/10), negative predictive value of 97.6% (41/42), positive likelihood ratio of 19.1 (95% confidence interval, 4.8-75.4), negative likelihood ratio of 0.1 (95% confidence interval, 0.02-0.7), and an accuracy of 94.2% (49/52) for the identification of intraamniotic infection (prevalence, 17% [9/52]); 2) the microbial load determined by the 16S nanopore sequencing had a strong positive correlation with the intensity of an intraamniotic inflammatory response (amniotic fluid interleukin 6 concentration; Spearman's correlation 0.9; P=.002); and 3) a subgroup of patients with intraamniotic inflammation did not have bacteria determined by culture, Sanger sequencing, or nanopore 16S, thus confirming the existence of sterile intraamniotic inflammation.

CONCLUSION

The 16S nanopore sequencing has high diagnostic indices, predictive values, likelihood ratios, and accuracy in the diagnosis of intraamniotic infection.

Placental Proteomics Reveals an Elevated Level of Aldo-Keto Reductase 1-B1, Highlighting Its Potential Role in Spontaneous Preterm Birth

Preterm birth (PTB) refers to the delivery of a baby before the completion of 37 weeks of gestation. It is a significant global health issue with implications for both mothers and neonates. The placenta is a transient organ crucial in the sustenance of pregnancy until parturition; its dysfunction is associated with different adverse pregnancy outcomes, including PTB. We conducted a nested case-control study of 40 placental tissue samples from preterm and term deliveries to study their comparative protein profiles. Label-free quantitation (LFQ) revealed 23 differentially expressed proteins (DEPs). Aldo-keto reductase-B1 (AKR1B1) protein expression profile exhibited a declining trajectory with an increasing period of gestation (POG). Immunoblotting and immunohistochemistry analyses of placental samples also revealed elevated protein levels in extreme preterm samples. AKR1B1 is a functional Prostaglandin F synthase responsible for the synthesis of Prostaglandin-F2α, a prostanoid that is elevated during parturition and involved in cervical ripening, membrane rupture, myometrial contraction, and inflammation. Hence, our finding supports the idea that elevated AKR1B1 levels play a significant role in the pathology of preterm birth by amplifying Prostaglandin-F2α synthesis in the placental milieu and can be further explored as a potential predictor of this condition. Data are available via ProteomeXchange with the identifier PXD043480.

Prediction of late-onset preeclampsia using plasma proteomics: a longitudinal multi-cohort study

Preeclampsia is a pregnancy disorder with substantial perinatal and maternal morbidity and mortality. Pregnant women at risk of preeclampsia would benefit from early detection for follow-up, timely interventions and delivery. Several attempts have been made to identify protein biomarkers of preeclampsia, but findings vary with demographics, clinical characteristics, and time of sampling. In the current study, we combined three independent longitudinal pregnancy cohorts (Detroit, Stanford and Oslo) resulting in 124 late-onset preeclampsia (LOPE) cases and 178 gestational age matched controls, and analyzed > 1000 proteins in maternal plasma sampled between 12 and 34 weeks of gestation. Differential abundance analysis of combined protein data revealed increased deviation in protein abundance trajectories throughout gestation in women destined to develop LOPE compared to controls. There were no differentially abundant proteins at time interval T1 (12-19 weeks), yet 31 differentially abundant proteins were found at time interval T2 (19-27 weeks), and 48 proteins at time interval T3 (27- 34 weeks). Multi-protein random forest models assessed via cross-validation predicted LOPE with an area under the ROC curve of 0.72 (0.65-0.78), 0.76 (0.71-0.81) and 0.80 (0.75-0.85) at time interval T1, T2 and T3, respectively. The results at T3 were confirmed using a leave-one-cohort-out analysis suggesting cross-cohort consistency, and at T1 and T2 when the largest two cohorts were used as training sets.

Causal Relationships Between Leukocyte Subsets and Adverse Fetal Outcomes: A Mendelian Randomization Study

Background: The tolerance and dynamic regulation of the maternal immune system during pregnancy are pivotal for ensuring fetal health. Immune cell subsets play a complex and crucial role in this process, closely linked to the neonatal health status. Despite recognizing the significance of dysregulation in the quantity and activity of immune cells in neonatal disease occurrence, their specific roles remain elusive, resulting in a dearth of clinically viable interventions for immune-mediated neonatal diseases. Materials and Methods: Employing two-sample Mendelian randomization (MR) methodology, this study systematically investigated 446 leukocyte features (N = 500,675), including leukocyte subsets, absolute cell (AC) counts, and morphological parameters (MP) and their correlation with seven adverse fetal outcomes (N = 1,100,458), encompassing fetal growth restriction (FGR), preterm birth (PTB), neonatal jaundice (NNJ), digestive system disorders of fetus and newborn (DSDFN), hemorrhagic and hematological disorders of fetus and newborn (HDFN), respiratory distress of newborn (RDN), and transitory disorders of metabolism specific to fetus and newborn (TDMSFN). Results: The results unveiled significant causal relationships between 301 leukocyte subsets and these seven adverse fetal outcomes, with 259, 245, 15, 44, 11, 32, and 68 pairs of notable associations for each adverse outcome, respectively. Furthermore, the study highlighted potential pathogenic mechanisms underlying the mutual influence among neonatal diseases. MR results indicated FGR as a robustly correlated risk factor for PTB and NNJ and showed a reciprocal causal relationship between NNJ and FGR. PTB exhibited a positive correlation with HDFN. Conclusions: This study provided profound insights into the intricate regulatory mechanisms of leukocyte subsets in neonatal diseases, paving the way for new avenues in the diagnosis and treatment of associated disorders.

The 36-week preeclampsia risk by the Fetal Medicine Foundation algorithm is associated with fetal compromise following induction of labor

BACKGROUND

Previous studies demonstrated that placental dysfunction leads to intrapartum fetal distress, particularly when an abnormal pattern of angiogenic markers is demonstrated at 36 weeks of gestation. The prediction of intrapartum fetal compromise is particularly important in patients undergoing induction of labor because of different indications for delivery, as this can be a useful in optimizing the method and timing of induction of labor.

OBJECTIVE

This study aimed to examine whether the risk of preeclampsia assessed using the Fetal Medicine Foundation algorithm (derived from a combination of maternal risk factors, mean arterial pressure, placental growth factor, and soluble fms-like tyrosine kinase-1) is associated with the risk of intrapartum fetal compromise requiring cesarean delivery in a population of patients with singleton pregnancies undergoing induction of labor for various indications.

STUDY DESIGN

This was a retrospective analysis on prospectively collected data from women with singleton pregnancies who underwent routine assessments at 35 0/7 to 36 6/7 weeks of gestation at King's College Hospital (London, United Kingdom). The study outcome was the rate of fetal compromise requiring cesarean delivery, examined in relation to the risk of preeclampsia assessed at 36 weeks of gestation using the Fetal Medicine Foundation risk model. Patients who underwent spontaneous labor and prelabor cesarean deliveries were excluded. In addition, 5 risk categories for preeclampsia were created on the basis of the Fetal Medicine Foundation 36-week risk model: A (≥1/2), B (<1/2- ≥1/5), C (<1/5- ≥1/20), D (<1/20-≥1/50), and E (<1/50). Based on the reason for induction of labor, we created 5 categories: premature rupture of membranes, postterm pregnancy (˃41 weeks of gestation), preeclampsia, fetal growth restriction (estimated fetal weight of ˂5th percentile), and preeclampsia and fetal growth restriction. A multinomial logistic regression was used to assess the risk of fetal compromise across the Fetal Medicine Foundation risk categories, accounting for all delivery outcomes (spontaneous or operative vaginal delivery and urgent cesarean delivery for fetal compromise, failure to progress, or other reasons) and allowing accurate and generalizable risk assessment of fetal compromise.

RESULTS

Of 45,375 pregnant women, 26,597 (58.6%) had spontaneous onset of labor, 6529 (14.0%) underwent elective prelabor cesarean delivery, which were excluded from the analysis. A total of 12,249 pregnant women were included, of which 182 had birth at ≤37 weeks of gestation and 1444 had fetal compromise (crude risk of 11.8%). The rate of vaginal delivery in the study population was 69.4%. The rates of fetal compromise in the 5 induction categories were 9.7% for premature rupture of membranes, 13.5% for postterm pregnancy, 14.8% for preeclampsia, 17.2% for fetal growth restriction, and 23.4% for preeclampsia and fetal growth restriction. Cases with intrapartum fetal compromise had a higher mean preeclampsia risk than cases without intrapartum fetal compromise (1/45 vs 1/81, respectively; P<.001). The risk of cesarean delivery for fetal compromise increased with (1) advancing gestational age (each week increase at 35-40 weeks: +1%; at 41-42 weeks: +5%), (2) nulliparity (+7%-10%) vs multiparity, (3) higher Fetal Medicine Foundation risk of preeclampsia (from the low-risk category of <1/50 to the high-risk category of ≥1/2: +18%; with greater effect for higher preeclampsia risk). In this study population, the rates of fetal compromise were lower with diagnoses of preeclampsia and rupture of membranes and higher with fetal growth restriction (alone or in combination with preeclampsia) and postterm pregnancy.

CONCLUSION

Our study highlights the clinical use of the Fetal Medicine Foundation 36-week PE risk model in determining the risk of fetal compromise requiring cesarean delivery after induction of labor. The same model can be combined with standard obstetric indications to induction of labour to establish the risk of fetal compromise requiring cesarean delivery. Therefore, the Fetal Medicine Foundation 36-week PE risk model can be used to optimize induction of labor.

Placenta may exert fetal protection against maternal high salt diet intake via renin-angiotensin-aldosterone system

OBJECTIVE

This study investigated the effects of high compared to normal dietary salt intake on fetoplacental vascular function, activity of renin-angiotensin-aldosterone system (RAAS), placental pro- and anti-angiogenic factors and biomarkers of placental remodeling and oxidative stress during healthy uncomplicated pregnancy.

MATERIALS AND METHODS

Based on their 24-h sodium excretion pregnant women (37-40 weeks' gestation) were categorized into three groups: normal salt (NS, <5.75 g/day, N = 12), high salt (HS, 5.75-10.25 g/day, N = 36), and very high salt (VHS, >10.25 g/day, N = 17). Pulsatility (PI) and resistive index of middle cerebral artery (MCA) and umbilical artery, plasma renin activity (PRA), serum aldosterone, soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) concentrations, as well as placental vascular endothelial growth factor C (VEGF-C), oxidative/antioxidative stress markers (TBARS/FRAP) and matrix metalloproteinase 9 (MMP-9) concentration were measured.

RESULTS

PI MCA was significantly decreased in HS/VHS groups compared to NS group. HS/VHS intake did not suppress PRA and aldosterone concentration. Serum PlGF concentration was significantly increased while sFlt-1 concentration and sFlt-1/PlGF ratio were significantly decreased in VHS group compared to NS group. MMP-9, VEGF-C concentration, TBARS and FRAP in placental tissue were similar between study groups.

CONCLUSIONS

HS/VHS diet does not suppress RAAS during pregnancy; however, it is associated with decreased PI MCA, a significantly decreased sFlt-1/PlGF ratio and unchanged biomarkers of placental remodeling or oxidative stress in healthy pregnant women, suggesting the presence of a possible protective or compensatory mechanism aimed at preserving placental function and pregnancy outcome itself in terms of maternal HS intake.

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.

Molecular evidence that GBS early neonatal sepsis results from ascending infection: comparative hybrid genomics analyses show that microorganisms in the vaginal ecosystem, amniotic fluid, chorioamniotic membranes, and neonatal blood are the same

OBJECTIVES

Streptococcus agalactiae, or Group B Streptococcus (GBS), is a leading cause of neonatal sepsis. Materno-fetal transmission of the microorganisms present in the lower genital tract/perineum is considered to be the most frequent mode for acquisition of infection. It has also been proposed that, in a subset of cases, GBS causes acute chorioamnionitis, intraamniotic infection, and fetal/neonatal sepsis. However, the evidence to support this ascending pathway is derived from microbiologic studies that rely on cultivation methods, which do not have the resolution to determine if the microorganisms causing neonatal sepsis are the same as those found in the amniotic fluid and the vaginal ecosystem.

METHODS

We used whole genome sequencing of the microorganisms isolated from the vagina, amniotic fluid, chorioamniotic membranes, and neonatal blood (four isolates) in a case of early neonatal sepsis. Using hybrid genome assembly, we characterized the genomic features including virulence factors and antimicrobial resistance in four isolates from the same mother, placenta, and newborn.

RESULTS

Whole genome sequencing revealed that the microorganisms in the four clinical isolates corresponded to S. agalactiae sequence type 1, clonal complexes 1, and serotype Ib. Comparative genomic analysis illustrated similar DNA sequences of the four genomes.

CONCLUSIONS

This study presents the first evidence of the genomic similarity of microorganisms in the vaginal ecosystem, the space between the chorioamniotic membranes of the placenta, amniotic fluid, and neonatal blood.

Placental differences between severe fetal growth restriction and hypertensive disorders of pregnancy requiring early preterm delivery: morphometric analysis of the villous tree supported by artificial intelligence

BACKGROUND

The great obstetrical syndromes of fetal growth restriction and hypertensive disorders of pregnancy can occur individually or be interrelated. Placental pathologic findings often overlap between these conditions, regardless of whether 1 or both diagnoses are present. Quantification of placental villous structures in each of these settings may identify distinct differences in developmental pathways.

OBJECTIVE

This study aimed to determine how the quantity and surface area of placental villi and vessels differ between severe, early-onset fetal growth restriction with absent or reversed umbilical artery Doppler indices and hypertensive disorders of pregnancy or the 2 conditions combined among subjects with disease severity that warrant early preterm delivery. We hypothesized that the trajectories of placental morphogenesis diverge after a common initiating insult of deep defective placentation. Specifically, we postulated that only villi are affected in pregnancy-related hypertension, whereas both villous and vascular structures are proportionally diminished in severe fetal growth restriction with no additional effect when hypertension is concomitantly present.

STUDY DESIGN

In this retrospective cohort study, paraffin-embedded placental tissue was obtained from 4 groups, namely (1) patients with severe fetal growth restriction with absent or reversed umbilical artery end-diastolic velocities and hypertensive disorders of pregnancy, (2) patients with severe fetal growth restriction with absent or reversed umbilical artery Doppler indices and no hypertension, (3) gestational age-matched, appropriately grown pregnancies with hypertensive disease, and (4) gestational age-matched, appropriately grown pregnancies without hypertension. Dual immunohistochemistry for cytokeratin-7 (trophoblast) and CD34 (endothelial cells) was performed, followed by artificial intelligence-driven morphometric analyses. The number of villi, total villous area, number of fetoplacental vessels, and total vascular area across villi within a uniform region of interest were quantified. Quantitative analyses of placental structures were modeled using linear regression.

RESULTS

Placentas from pregnancies complicated by hypertensive disorders of pregnancy exhibited significantly fewer stem villi (-282 stem villi; 95% confidence interval, -467 to -98; P<.01), a smaller stem villous area (-4.3 mm2; 95% confidence interval, -7.3 to -1.2; P<.01), and fewer stem villous vessels (-4967 stem villous vessels; 95% confidence interval, -8501 to -1433; P<.01) with no difference in the total vascular area. In contrast, placental abnormalities in cases with severe growth restriction were limited to terminal villi with global decreases in the number of villi (-873 terminal villi; 95% confidence interval, -1501 to -246; P<.01), the villous area (-1.5 mm2; 95% confidence interval, -2.7 to -0.4; P<.01), the number of blood vessels (-5165 terminal villous vessels; 95% confidence interval, -8201 to -2128; P<.01), and the vascular area (-0.6 mm2; 95% confidence interval, -1.1 to -0.1; P=.02). The combination of hypertension and growth restriction had no additional effect beyond the individual impact of each state.

CONCLUSION

Pregnancies complicated by hypertensive disorders of pregnancy exhibited defects in the stem villi only, whereas placental abnormalities in severely growth restricted pregnancies with absent or reversed umbilical artery end-diastolic velocities were limited to the terminal villi. There were no significant statistical interactions in the combination of growth restriction and hypertension, suggesting that distinct pathophysiological pathways downstream of the initial insult of defective placentation are involved in each entity and do not synergize to lead to more severe pathologic consequences. Delineating mechanisms that underly the divergence in placental development after a common inciting event of defective deep placentation may shed light on new targets for prevention or treatment.

Proteomic Profiles of Maternal Plasma Extracellular Vesicles for Prediction of Preeclampsia

PROBLEM

Preeclampsia is a heterogeneous syndrome of diverse etiologies and molecular pathways leading to distinct clinical subtypes. Herein, we aimed to characterize the extracellular vesicle (EV)-associated and soluble fractions of the maternal plasma proteome in patients with preeclampsia and to assess their value for disease prediction.

METHOD OF STUDY

This case-control study included 24 women with term preeclampsia, 23 women with preterm preeclampsia, and 94 healthy pregnant controls. Blood samples were collected from cases on average 7 weeks before the diagnosis of preeclampsia and were matched to control samples. Soluble and EV fractions were separated from maternal plasma; EVs were confirmed by cryo-EM, NanoSight, and flow cytometry; and 82 proteins were analyzed with bead-based, multiplexed immunoassays. Quantile regression analysis and random forest models were implemented to evaluate protein concentration differences and their predictive accuracy. Preeclampsia subgroups defined by molecular profiles were identified by hierarchical cluster analysis. Significance was set at p < 0.05 or false discovery rate-adjusted q < 0.1.

RESULTS

In preterm preeclampsia, PlGF, PTX3, and VEGFR-1 displayed differential abundance in both soluble and EV fractions, whereas angiogenin, CD40L, endoglin, galectin-1, IL-27, CCL19, and TIMP1 were changed only in the soluble fraction (q < 0.1). The direction of changes in the EV fraction was consistent with that in the soluble fraction for nine proteins. In term preeclampsia, CCL3 had increased abundance in both fractions (q < 0.1). The combined EV and soluble fraction proteomic profiles predicted preterm and term preeclampsia with an AUC of 78% (95% CI, 66%-90%) and 68% (95% CI, 56%-80%), respectively. Three clusters of preeclampsia featuring distinct clinical characteristics and placental pathology were identified based on combined protein data.

CONCLUSIONS

Our findings reveal distinct alterations of the maternal EV-associated and soluble plasma proteome in preterm and term preeclampsia and identify molecular subgroups of patients with distinct clinical and placental histopathologic features.

First trimester risk of preeclampsia and rate of spontaneous birth in patients without preeclampsia

BACKGROUND

First-trimester screening for preeclampsia using a combination of maternal risk factors and mean arterial pressure, uterine artery pulsatility index, and placental growth factor, as proposed by the Fetal Medicine Foundation, provides effective prediction of preterm preeclampsia. Placental dysfunction is a potential precursor of spontaneous birth.

OBJECTIVE

The objective of this study was to examine if the estimated risk of preeclampsia is associated with the gestational age at onset of spontaneous delivery in the absence of preeclampsia.

STUDY DESIGN

This was a secondary analysis of the data from the Screening programme for pre-eclampsia trial in which there was a comparison of the performance of first-trimester screening for preterm preeclampsia using the Fetal Medicine Foundation model vs a traditional history-based risk scoring system. A subgroup of women from the trial with spontaneous onset of delivery (labor with intact membranes or preterm prelabor rupture of membranes) was included in this study and was arbitrarily divided into 3 groups according to the risk for preterm preeclampsia as determined by the Fetal Medicine Foundation model at 11 to 13 weeks' gestation as follows: group 1 low risk (˂1/100); group 2 intermediate risk (1/50 to 1/100); and group 3 high risk (˃1/50). A survival analysis was carried out using a Kaplan-Meier estimator and a Cox regression analysis with stratification by the 3 preeclampsia risk groups. Occurrence of spontaneous birth in the study groups was compared using log-rank tests and hazard ratios.

RESULTS

The study population comprised 10,820 cases with delivery after spontaneous onset of labor among the 16,451 cases who participated in the Screening programme for pre-eclampsia trial. There were 9795 cases in group 1, 583 in group 2, and 442 in group 3. The gestational age at delivery was <28, <32, <35, <37, and <40 weeks in 0.29%, 0.64%, 1.68%, 4.52%, and 44.97% of cases, respectively, in group 1; 0.69%, 1.71%, 3.26%, 7.72%, and 55.23% of cases, respectively, in group 2; and 0.45%, 1.81%, 5.66%, 13.80%, and 63.12% of cases, respectively, in group 3. The curve profile of gestational age at spontaneous birth in the 3 study groups was significantly different overall and in pairwise comparisons (P values <.001). The Cox regression analysis showed that risks increased for spontaneous birth by 18% when the intermediate-risk group was compared with the low-risk group (P˂.001) and by 41% when the high-risk group was compared with the low-risk group (P˂.001).

CONCLUSION

In this study that investigated birth after spontaneous onset of labor in women without preeclampsia, there were 2 major findings. First, the duration of pregnancy decreased with increasing first-trimester risk for preeclampsia. Second, in the high-risk group, when compared with the low-risk group, the risk for spontaneous birth was 4 times higher at a gestational age of 24 to 26 weeks, 3 times higher at 28 to 32 weeks, and 2 times higher at 34 to 39 weeks. These differences present major clinical implications for antepartum counselling, monitoring, and interventions in these pregnancies.

Plasma soluble fms-like tyrosine kinase 1 to placental growth factor ratio of 11.5 multiples of median predicts preeclampsia with severe features within 2 weeks of testing

BACKGROUND

Angiogenic imbalances, characterized by an excess of antiangiogenic factors (soluble fms-like tyrosine kinase 1) and reduced angiogenic factors (vascular endothelial growth factor and placental growth factor), contribute to the mechanisms of disease in preeclampsia. The ratio of soluble fms-like tyrosine kinase 1 to placental growth factor has been used as a biomarker for preeclampsia, but the cutoff values may vary with gestational age and assay platform.

OBJECTIVE

This study aimed to compare multiples of the median of the maternal plasma soluble fms-like tyrosine kinase 1 to placental growth factor ratio, soluble fms-like tyrosine kinase 1, placental growth factor, and conventional clinical and laboratory values in their ability to predict preeclampsia with severe features.

STUDY DESIGN

We conducted a cohort study across 18 United States centers involving hospitalized individuals with hypertension between 23 and 35 weeks' gestation. Receiver operating characteristic curve analyses of maternal plasma biomarkers, highest systolic or diastolic blood pressures, and laboratory values at enrollment were performed for the prediction of preeclampsia with severe features. The areas under the curve were compared, and quasi-Poisson regression models were fitted to estimate relative risks. The primary outcome was preeclampsia with severe features within 2 weeks of enrollment. Secondary outcomes were a composite of severe adverse maternal outcomes (elevated liver enzymes, low platelets count, placental abruption, eclampsia, disseminated intravascular coagulation, and pulmonary edema) and a composite of severe adverse perinatal outcomes (birth weight below the third percentile, very preterm birth [<32 weeks' gestation], and fetal or neonatal death).

RESULTS

Of the 543 individuals included in the study, preeclampsia with severe features within 2 weeks was observed in 33.1% (n=180) of them. A receiver operating characteristic curve-derived cutoff of 11.5 multiples of the median for the soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio provided good sensitivity (90.6%), specificity (76.9%), positive predictive value (66.0%), negative predictive value (94.3%), positive likelihood ratio (3.91), negative likelihood ratio (0.12), and accuracy (81.4%) for preeclampsia with severe features within 2 weeks. This cutoff was used to compare test positive cases (≥ cutoff) and test negative cases (< cutoff). Preeclampsia with severe features (66.0% vs 5.7%; P<.001) and composites of severe adverse maternal (8.11% vs 2.7%; P=.006) or perinatal (41.3% vs 10.14%; P=.001) outcomes within 2 weeks were more frequent in test positive cases than in test negative cases. A soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio ≥11.5 multiples of the median was independently associated with preeclampsia with severe features (adjusted incidence rate ratio, 9.08; 95% confidence interval, 6.11-14.06; P<.001) and a composite of severe adverse perinatal outcomes (adjusted incidence rate ratio, 9.42; 95% confidence interval, 6.36-14.53; P<.001) but not with a composite of severe adverse maternal outcomes (adjusted incidence rate ratio, 2.20; 95% confidence interval, 0.95-5.54; P=.08). The area under the curve for the soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio in multiples of the median (0.91; 95% confidence interval, 0.89-0.94) for preeclampsia with severe features within 2 weeks was significantly higher (P<.001 for all comparisons) than either plasma biomarker alone or any other parameter with the exception of absolute soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio values.

CONCLUSION

A soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio ≥11.5 multiples of the mean among hospitalized patients with hypertension between 23 and 35 week's gestation predicts progression to preeclampsia with severe features and severe adverse perinatal outcomes within 2 weeks.

Umbilical-portal-systemic venous shunt and intrauterine growth restriction: an inquiry from a prospective study

BACKGROUND

The investigation of the fetal umbilical-portal venous system is based on the premise that congenital anomalies of this system may be related to adverse perinatal outcomes. Several small retrospective studies have reported an association between umbilical-portal-systemic venous shunts and intrauterine growth restriction. However, the prevalence of portosystemic shunts in the fetal growth restricted population is yet to be determined.

OBJECTIVE

The aims of this study were (1) to determine the prevalence of fetal umbilical-portal-systemic venous shunts in pregnancies complicated by intrauterine growth restriction and (2) to compare the perinatal and neonatal outcomes of pregnancies with intrauterine growth restriction with and without umbilical-portal-systemic venous shunts.

STUDY DESIGN

This was a prospective, cross-sectional study of pregnancies diagnosed with intrauterine growth restriction, as defined by the Society for Maternal-Fetal Medicine intrauterine growth restriction guidelines. All participants underwent a detailed anomaly scan, supplemented with a targeted scan of the fetal portal system. Venous shunts were diagnosed using color Doppler mode. The perinatal outcomes of pregnancies with intrauterine growth restriction with and without umbilical-portal-systemic venous shunts were compared.

RESULTS

A total of 150 cases with intrauterine growth restriction were recruited. The prevalence of umbilical-portal-systemic venous shunts in our cohort was 9.3% (n=14). When compared with the control group (intrauterine growth restriction without umbilical-portal-systemic venous shunts, n=136), the study group had a significantly lower mean gestational age at the time of intrauterine growth restriction diagnosis (29.7±5.6 vs 32.47±4.6 weeks of gestation; P=.036) and an earlier gestational age at delivery (33.50±6.0 vs 36.13±2.8; P=.005). The study group had a higher rate of fetal death (21.4% vs 0.7%; P<.001) and, accordingly, a lower rate of live births (71.4% vs 95.6%; P=.001). Additional associated fetal vascular anomalies were significantly more prevalent in the study group than in the control group (35.7% vs 4.4%; P≤.001). The rate of other associated anomalies was similar. The study group had a significantly lower rate of abnormal uterine artery Doppler indices (0% vs 40.4%; P=.011) and a higher rate of abnormal ductus venosus Doppler indices (64.3% vs 23%; P=.001). There were no cases of hypertensive disorders of pregnancy in the study group, whereas the control group had an incidence of 12.5% (P=.16). Other perinatal and neonatal outcomes were comparable.

CONCLUSION

Umbilical-portal-systemic venous shunt is a relatively common finding among fetuses with growth restriction. When compared with pregnancies with intrauterine growth restriction with a normal portal system, these pregnancies complicated by intrauterine growth restriction and an umbilical-portal-systemic venous shunt are associated with a different Doppler flow pattern, an increased risk for fetal death, earlier presentation of intrauterine growth restriction, a lower gestational age at delivery, additional congenital vascular anomalies, and a lower rate of pregnancy-induced hypertensive disorders. Meticulous sonographic evaluation of the portal system should be considered in the prenatal workup of intrauterine growth restriction, as umbilical-portal-systemic venous shunts may affect perinatal outcomes.

Neonatal Encephalopathy is a Complex Phenotype Representing Reproductive and Pregnancy Exposome Effects on the Maternal-Placental-Fetal Triad

Reproductive, pregnancy, and placental exposomes influence the fetal neural exposome through toxic stressor interplay, impairing the maternal-placental-fetal (MPF) triad. Neonatal encephalopathy represents different clinical presentations based on complex time-dependent etiopathogenetic mechanisms including hypoxia-ischemia that challenge diagnosis and prognosis. Reproductive, pregnancy, and placental exposomes impair the fetal neural exposome through toxic stressor interplay within the MPF triad. Long intervals often separate disease onset from phenotype. Interdisciplinary fetal-neonatal neurology training, practice, and research closes this knowledge gap. Maintaining reproductive health preserves MPF triad health with life-course benefits.

Predictive Value of the sFlt-1/PlGF Ratio and Interleukin-6 for the Presence of Placental Lesions in Spontaneous Preterm Labor with Intact Membranes with Delivery within 7 Days

INTRODUCTION

The aim of the study was to identify predictive values of the soluble fms-like tyrosine kinase/placental growth factor (sFlt-1/PlGF) ratio and interleukin (IL)-6, assessed with a clinically available method in a large-volume biochemistry laboratory, in maternal blood, amniotic fluid, and umbilical cord blood for the presence of the placental lesions consistent with maternal vascular malperfusion (MVM) and acute histological chorioamnionitis (HCA), respectively.

METHODS

This retrospective study included 92 women with preterm labor with intact membranes (PTL) delivered within 7 days of admission with gestational ages between 22+0 and 34+6 weeks. The sFlt-1/PlGF ratio and IL-6 were assessed in stored samples of maternal serum, amniotic fluid, and umbilical cord serum using Elecsys® sFlt-1, PlGF, and IL-6 immunoassays.

RESULTS

Women with MVM had a higher sFlt-1/PlGF ratio in the maternal serum, compared to those without MVM (19.9 vs. 4.6; p < 0.0001), but not in the amniotic fluid or umbilical cord blood. A cut-off value of 8 for the sFlt-1/PlGF ratio in maternal serum was identified as optimal for predicting MVM in patients with PTL. Women with HCA had higher concentrations of IL-6 in maternal serum, compared to those without HCA (11.1 pg/mL vs. 8.4 pg/mL; p = 0.03), amniotic fluid (9,216 pg/mL vs. 1,423 pg/mL; p < 0.0001), and umbilical cord blood (20.7 pg/mL vs. 10.7 pg/mL, p = 0.002). Amniotic-fluid IL-6 showed the highest predictive value. A cut-off value of IL-6 concentration in the amniotic fluid of 5,000 pg/mL was found to be optimal for predicting HCA in PTL.

CONCLUSION

Maternal serum sFlt-1/PlGF and amniotic fluid IL-6 concentrations can be used for liquid biopsy to predict placental lesions in women with PTL who deliver within 7 days.

Prediction of preterm birth in women with fetal growth restriction - Is the weekly change in sFlt-1/PlGF ratio or PlGF levels useful?

INTRODUCTION

To assess the rate of change in soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio and PlGF levels per week compared to a single sFlt-1/PlGF ratio or PlGF level to predict preterm birth for pregnancies complicated by fetal growth restriction.

MATERIAL AND METHODS

A prospective cohort study of pregnancies complicated by isolated fetal growth restriction. Maternal serum PlGF levels and the sFlt-1/PlGF ratio were measured at 4-weekly intervals from recruitment to delivery. We investigated the utility of PlGF levels, sFlt-1/PlGF ratio, change in PlGF levels per week or sFlt-1/PlGF ratio per week. Cox-proportional hazard models and Harrell's C concordance statistic were used to evaluate the effect of biomarkers on time to preterm birth.

RESULTS

The total study cohort was 158 pregnancies comprising 91 (57.6%) with fetal growth restriction and 67 (42.4%) with appropriate for gestational age controls. In the fetal growth restriction cohort, sFlt-1/PlGF ratio and PlGF levels significantly affected time to preterm birth (Harrell's C: 0.85-0.76). The rate of increase per week of the sFlt-1/PlGF ratio (hazard ratio [HR] 3.91, 95% confidence interval [CI]: 1.39-10.99, p = 0.01, Harrell's C: 0.74) was positively associated with preterm birth but change in PlGF levels per week was not (HR 0.65, 95% CI: 0.25-1.67, p = 0.37, Harrell's C: 0.68).

CONCLUSIONS

Both a high sFlt-1/PlGF ratio and low PlGF levels are predictive of preterm birth in women with fetal growth restriction. Although the rate of increase of the sFlt-1/PlGF ratio predicts preterm birth, it is not superior to either a single elevated sFlt-1/PlGF ratio or low PlGF level.

Etiologically Based Functional Taxonomy of the Preterm Birth Syndrome

Preterm birth (PTB) is a complex syndrome traditionally defined by a single parameter, namely, gestational age at birth (ie, ˂37 weeks). This approach has limitations for clinical usefulness and may explain the lack of progress in identifying cause-specific effective interventions. The authors offer a framework for a functional taxonomy of PTB based on (1) conceptual principles established a priori; (2) known etiologic factors; (3) specific, prospectively identified obstetric and neonatal clinical phenotypes; and (4) postnatal follow-up of growth and development up to 2 years of age. This taxonomy includes maternal, placental, and fetal conditions routinely recorded in data collection systems.

The sFlt-1/PlGF Ratio at 12, 24, and 32 Weeks Gestation in Twin Pregnancies as a Predictor of Late Preterm Birth and Perinatal Event Secondary to Prematurity

Background: Preterm birth impacts 60% of twin pregnancies, with the subsequent risk of complications in both newborns secondary to the immaturity of organs. This study aims to assess the utility of the sFlt-1/PlGF ratio throughout pregnancy in predicting late preterm birth and adverse perinatal outcomes related to prematurity in twin pregnancies. Methods: This is a prospective cohort study developed at a tertiary hospital. All pregnant women with a twin pregnancy who signed the informed consent were included. The sFlt-1/PlGF ratio was measured at 12, 24, and 32 weeks' gestation. Results: Seventy patients were included, from which 54.3% suffered late preterm birth. Results revealed a significant difference in sFlt-1/PlGF ratio at week 32 between term and preterm groups, with a one-unit increase associated with a 1.11-fold increase in the probability of preterm birth. The sFlt-1/PlGF ratio at week 32 alone presented considerable predictive capacities (sensitivity of 71%, specificity of 72%, a PPV of 75%, and an NPV of 68%. Similarly, at week 24, a one-unit increase in sFlt-1/PlGF ratio was associated with a 1.24-fold increase in the probability of adverse perinatal events due to prematurity. Combining parity, maternal age, conception method, BMI, and chorionicity, the model yielded better predictive capacities (sensitivity of 82%, specificity of 80%, PPV of 58%, NPV of 93%). Conclusions: The potential of the sFlt-1/PlGF ratio as a predictive tool for preterm birth and adverse perinatal outcomes secondary to prematurity in twin pregnancies is underscored.

Preeclampsia at term: evidence of disease heterogeneity based on the profile of circulating cytokines and angiogenic factors

BACKGROUND

Intravascular inflammation and an antiangiogenic state have been implicated in the pathophysiology of preeclampsia. On the basis of the profiles of their angiogenic/antiangiogenic factors, women with preeclampsia at term may be classified into 2 subgroups with different characteristics and prevalence of adverse outcomes. This study was undertaken to examine whether these 2 subgroups of preeclampsia at term also show differences in their profiles of intravascular inflammation.

OBJECTIVE

This study aimed to determine the plasma profiles of cytokines and chemokines in women with preeclampsia at term who had a normal or an abnormal angiogenic profile.

STUDY DESIGN

A nested case-control study was conducted to include women classified into 3 groups: women with an uncomplicated pregnancy (n=213) and women with preeclampsia at term with a normal (n=55) or an abnormal (n=41) angiogenic profile. An abnormal angiogenic profile was defined as a plasma ratio of placental growth factor and soluble fms-like tyrosine kinase-1 multiple of the median <10th percentile for gestational age. Concentrations of cytokines were measured by multiplex immunoassays.

RESULTS

Women with preeclampsia at term and an abnormal angiogenic profile showed evidence of the greatest intravascular inflammation among the study groups. These women had higher plasma concentrations of 5 cytokines (interleukin-6, interleukin-8, interleukin-12/interleukin-23p40, interleukin-15, and interleukin-16) and 7 chemokines (eotaxin, eotaxin-3, interferon-γ inducible protein-10, monocyte chemotactic protein-4, macrophage inflammatory protein-1β, macrophage-derived chemokine, and thymus and activation-regulated chemokine compared to women with an uncomplicated pregnancy. By contrast, women with preeclampsia at term and a normal angiogenic profile, compared to women with an uncomplicated pregnancy, had only a higher plasma concentration of monocyte chemotactic protein-4. A correlation between severity of the antiangiogenic state, blood pressure, and plasma concentrations of a subset of cytokines was observed.

CONCLUSION

Term preeclampsia can be classified into 2 clusters. One is characterized by an antiangiogenic state coupled with an excessive inflammatory process, whereas the other has neither of these features. These findings further support the heterogeneity of preeclampsia at term and may explain the distinct clinical outcomes.

MicroRNA Associations with Preterm Labor-A Systematic Review

This systematic review delves into the connections between microRNAs and preterm labor, with a focus on identifying diagnostic and prognostic markers for this crucial pregnancy complication. Covering studies disseminated from 2018 to 2023, the review integrates discoveries from diverse pregnancy-related scenarios, encompassing gestational diabetes, hypertensive disorders and pregnancy loss. Through meticulous search strategies and rigorous quality assessments, 47 relevant studies were incorporated. The synthesis highlights the transformative potential of microRNAs as valuable diagnostic tools, offering promising avenues for early intervention. Notably, specific miRNAs demonstrate robust predictive capabilities. In conclusion, this comprehensive analysis lays the foundation for subsequent research, intervention strategies and improved outcomes in the realm of preterm labor.

Classification of preeclampsia according to molecular clusters with the goal of achieving personalized prevention

The prevention of pre-eclampsia is difficult due to the syndromic nature and multiple underlying mechanisms of this severe complication of pregnancy. The current clinical distinction between early- and late-onset disease, although clinically useful, does not reflect the true nature and complexity of the pathologic processes leading to pre-eclampsia. The current gaps in knowledge on the heterogeneous molecular pathways of this syndrome and the lack of adequate, specific diagnostic methods are major obstacles to early screening and tailored preventive strategies. The development of novel diagnostic tools for detecting the activation of the identified disease pathways would enable early, accurate screening and personalized preventive therapies. We implemented a holistic approach that includes the utilization of different proteomic profiling methods of maternal plasma samples collected from various ethnic populations and the application of systems biology analysis to plasma proteomic, maternal demographic, clinical characteristic, and placental histopathologic data. This approach enabled the identification of four molecular subclasses of pre-eclampsia in which distinct and shared disease mechanisms are activated. The current review summarizes the results and conclusions from these studies and the research and clinical implications of our findings.

Antibiotic treatment reduces the intensity of intraamniotic inflammation in pregnancies with idiopathic vaginal bleeding in the second trimester of pregnancy

BACKGROUND

Idiopathic bleeding in the second trimester of pregnancy complicates <1% of all pregnancies. This pregnancy complication can be caused by alterations in local hemostasis in the decidua due to infection/inflammation in the choriodecidual niche. This condition is associated with intraamniotic inflammatory complications. Antibiotic therapy effectively reduces the intensity of intraamniotic inflammation in certain pregnancy pathologies. However, whether antibiotic administration can reduce the intensity of the intraamniotic inflammatory response or eradicate microorganisms in patients with idiopathic bleeding during the second trimester of pregnancy remains unclear.

OBJECTIVE

This study primarily aimed to determine whether antimicrobial agents can reduce the magnitude of intraamniotic inflammation in patients with idiopathic bleeding in the second trimester of pregnancy by assessing the concentration of interleukin-6 in the amniotic fluid before and after 7 days of antibiotic treatment. The secondary aim was to determine whether treatment with a combination of antibiotics altered the microbial load of Ureaplasma species DNA in amniotic fluid.

STUDY DESIGN

This retrospective cohort study included singleton-gestation patients with idiopathic bleeding between 15+0 and 27+6 weeks who underwent transabdominal amniocentesis at the time of admission. Follow-up amniocentesis was performed in a subset of patients unless abortion or delivery occurred earlier. Concentrations of interleukin-6 were measured in the amniotic fluid samples, and the presence of microbial invasion of the amniotic cavity was assessed using culture and molecular microbiological methods. Intraamniotic inflammation was defined as an interleukin-6 concentration ≥3000 pg/mL in the amniotic fluid samples.

RESULTS

A total of 36 patients with idiopathic bleeding in the second trimester of pregnancy were included. All the patients underwent initial amniocentesis. Patients with intraamniotic inflammation (n=25) were treated using a combination of antibiotics consisting of intravenous ceftriaxone, intravenous metronidazole, and peroral clarithromycin. The patients without intraamniotic inflammation (n=11) were treated expectantly. In total, 25 patients delivered 7 days after admission. All patients with intraamniotic inflammation at the initial amniocentesis who delivered after 7 days underwent follow-up amniocentesis. Treatment with antibiotics decreased the interleukin-6 concentration in the amniotic fluid at follow-up amniocentesis compared with that at the initial amniocentesis in patients with intraamniotic inflammation (median [interquartile range]: 3457 pg/mL [2493-13,203] vs 19,812 pg/mL [11,973-34,518]; P=.0001). Amniotic fluid samples with Ureaplasma species DNA had a lower microbial load at the time of follow-up amniocentesis compared with the initial amniocentesis (median [interquartile range]: 1.5×105 copies DNA/mL [1.3×105-1.7×105] vs 8.0×107 copies DNA/mL [6.7×106-1.6×108]; P=.02).

CONCLUSION

Antibiotic therapy was associated with reduced intraamniotic inflammation in patients with idiopathic bleeding in the second trimester complicated by intraamniotic inflammation. Moreover, antibiotic treatment has been associated with a reduction in the microbial load of Ureaplasma species DNA in the amniotic fluid.

Interdisciplinary fetal-neonatal neurology training applies neural exposome perspectives to neurology principles and practice

An interdisciplinary fetal-neonatal neurology (FNN) program over the first 1,000 days teaches perspectives of the neural exposome that are applicable across the life span. This curriculum strengthens neonatal neurocritical care, pediatric, and adult neurology training objectives. Teaching at maternal-pediatric hospital centers optimally merges reproductive, pregnancy, and pediatric approaches to healthcare. Phenotype-genotype expressions of health or disease pathways represent a dynamic neural exposome over developmental time. The science of uncertainty applied to FNN training re-enforces the importance of shared clinical decisions that minimize bias and reduce cognitive errors. Trainees select mentoring committee participants that will maximize their learning experiences. Standardized questions and oral presentations monitor educational progress. Master or doctoral defense preparation and competitive research funding can be goals for specific individuals. FNN principles applied to practice offer an understanding of gene-environment interactions that recognizes the effects of reproductive health on the maternal-placental-fetal triad, neonate, child, and adult. Pre-conception and prenatal adversities potentially diminish life-course brain health. Endogenous and exogenous toxic stressor interplay (TSI) alters the neural exposome through maladaptive developmental neuroplasticity. Developmental disorders and epilepsy are primarily expressed during the first 1,000 days. Communicable and noncommunicable illnesses continue to interact with the neural exposome to express diverse neurologic disorders across the lifespan, particularly during the critical/sensitive time periods of adolescence and reproductive senescence. Anomalous or destructive fetal neuropathologic lesions change clinical expressions across this developmental-aging continuum. An integrated understanding of reproductive, pregnancy, placental, neonatal, childhood, and adult exposome effects offers a life-course perspective of the neural exposome. Exosome research promises improved disease monitoring and drug delivery starting during pregnancy. Developmental origins of health and disease principles applied to FNN practice anticipate neurologic diagnoses with interventions that can benefit successive generations. Addressing health care disparities in the Global South and high-income country medical deserts require constructive dialogue among stakeholders to achieve medical equity. Population health policies require a brain capital strategy that reduces the global burden of neurologic diseases by applying FNN principles and practice. This integrative neurologic care approach will prolong survival with an improved quality of life for persons across the lifespan confronted with neurological disorders.

mRNA and Protein Expression in Human Fetal Membrane Cells: Potential Biomarkers for Preterm Prelabor Rupture of the Fetal Membranes?

Clinically, unique markers in fetal membrane cells may contribute to the search for biomarkers for preterm prelabor rupture of the fetal membranes (pPROM) in maternal blood. pPROM is associated with overwhelming inflammation and premature cellular senescence causing "biological microfractures" of the fetal membranes. We hypothesize that these pathological processes are associated with the shedding of fetal membrane cells into the maternal circulation. The aim of this study was to identify markers expressed exclusively in fetal membrane cells to facilitate their isolation, characterization, and determination of biomarker potential in maternal blood. We have (1), by their transcriptomic profile, identified markers that are upregulated in amnion and chorion tissue compared to maternal white blood cells, and (2), by immunohistochemistry, confirmed the localization of the differentially expressed proteins in fetal membranes, placenta, and the placental bed of the uterus. RNA sequencing revealed 31 transcripts in the amnion and 42 transcripts in the chorion that were upregulated. Among these, 22 proteins were evaluated by immunohistochemistry. All but two transcripts were expressed both on mRNA and protein level in at least one fetal membrane cell type. Among these remaining 20 proteins, 9 proteins were not significantly expressed in the villous and extravillous trophoblasts of the placenta.

Prepregnancy obesity and risk of placental inflammation at term: a selection bias analysis

PURPOSE

Placental histopathology is a resource for investigating obesity-associated pregnancy conditions. However, studies oversample adverse pregnancies, biasing findings. We examine the association between prepregnancy obesity (risk factor for inflammation) and histologic placental inflammation (correlated with impaired infant neurodevelopment) and how selection bias may influence the association.

METHODS

Singleton term deliveries between 2008 and 2012 from the Magee Obstetric Maternal and Infant database were analyzed. Prepregnancy body mass index (BMI) was categorized as underweight, lean (referent), overweight, and obese. Outcomes were diagnoses of acute (acute chorioamnionitis and fetal inflammation) and chronic placental inflammation (chronic villitis). Risk ratios for associations between BMI and placental inflammation were estimated using selection bias approaches: complete case, exclusion of pregnancy complications, multiple imputation, and inverse probability weighting. E-values approximated how susceptible estimates were to residual selection bias.

RESULTS

Across methods, obesity was associated with an 8-15% lower risk of acute chorioamnionitis, a 7%-14% lower risk of acute fetal inflammation, and a 12%-30% higher risk of chronic villitis relative to lean women. E-values indicated modest residual selection bias could explain away associations, though few measured indications of placental evaluations met this threshold.

CONCLUSIONS

Obesity may contribute to placental inflammation, and we highlight robust methods to analyze clinical data susceptible to selection bias.

Preterm preeclampsia screening using biomarkers: combining phenotypic classifiers into robust prediction models

BACKGROUND

Preeclampsia screening is a critical component of antenatal care worldwide. Currently, the most developed screening test for preeclampsia at 11 to 13 weeks' gestation integrates maternal demographic characteristics and medical history with 3 biomarkers-serum placental growth factor, mean arterial pressure, and uterine artery pulsatility index-to identify approximately 75% of women who develop preterm preeclampsia with delivery before 37 weeks of gestation. It is generally accepted that further improvements to preeclampsia screening require the use of additional biomarkers. We recently reported that the levels of specific metabolites and metabolite ratios are associated with preterm preeclampsia. Notably, for several of these markers, preterm preeclampsia prediction varied according to maternal body mass index class. These findings motivated us to study whether patient classification allowed for combining metabolites with the current biomarkers more effectively to improve prediction of preterm preeclampsia.

OBJECTIVE

This study aimed to investigate whether metabolite biomarkers can improve biomarker-based preterm preeclampsia prediction in 3 screening resource scenarios according to the availability of: (1) placental growth factor, (2) placental growth factor+mean arterial pressure, and (3) placental growth factor+mean arterial pressure+uterine artery pulsatility index.

STUDY DESIGN

This was an observational case-control study, drawn from a large prospective screening study at 11 to 13 weeks' gestation on the prediction of pregnancy complications, conducted at King's College Hospital, London, United Kingdom. Maternal blood samples were also collected for subsequent research studies. We used liquid chromatography-mass spectrometry to quantify levels of 50 metabolites previously associated with pregnancy complications in plasma samples from singleton pregnancies. Biomarker data, normalized using multiples of medians, on 1635 control and 106 preterm preeclampsia pregnancies were available for model development. Modeling was performed using a methodology that generated a prediction model for preterm preeclampsia in 4 consecutive steps: (1) z-normalization of predictors, (2) combinatorial modeling of so-called (weak) classifiers in the unstratified patient set and in discrete patient strata based on body mass index and/or race, (3) selection of classifiers, and (4) aggregation of the selected classifiers (ie, bagging) into the final prediction model. The prediction performance of models was evaluated using the area under the receiver operating characteristic curve, and detection rate at 10% false-positive rate.

RESULTS

First, the predictor development methodology itself was evaluated. The patient set was split into a training set (2/3) and a test set (1/3) for predictor model development and internal validation. A prediction model was developed for each of the 3 different predictor panels, that is, placental growth factor+metabolites, placental growth factor+mean arterial pressure+metabolites, and placental growth factor+mean arterial pressure+uterine artery pulsatility index+metabolites. For all 3 models, the area under the receiver operating characteristic curve in the test set did not differ significantly from that of the training set. Next, a prediction model was developed using the complete data set for the 3 predictor panels. Among the 50 metabolites available for modeling, 26 were selected across the 3 prediction models; 21 contributed to at least 2 out of the 3 prediction models developed. Each time, area under the receiver operating characteristic curve and detection rate were significantly higher with the new prediction model than with the reference model. Markedly, the estimated detection rate with the placental growth factor+mean arterial pressure+metabolites prediction model in all patients was 0.58 (95% confidence interval, 0.49-0.70), a 15% increase (P<.001) over the detection rate of 0.43 (95% confidence interval, 0.33-0.55) estimated for the reference placental growth factor+mean arterial pressure. The same prediction model significantly improved detection in Black (14%) and White (19%) patients, and in the normal-weight group (18.5≤body mass index<25) and the obese group (body mass index≥30), with respectively 19% and 20% more cases detected, but not in the overweight group, when compared with the reference model. Similar improvement patterns in detection rates were found in the other 2 scenarios, but with smaller improvement amplitudes.

CONCLUSION

Metabolite biomarkers can be combined with the established biomarkers of placental growth factor, mean arterial pressure, and uterine artery pulsatility index to improve the biomarker component of early-pregnancy preterm preeclampsia prediction tests. Classification of the pregnant women according to the maternal characteristics of body mass index and/or race proved instrumental in achieving improved prediction. This suggests that maternal phenotyping can have a role in improving the prediction of obstetrical syndromes such as preeclampsia.

Accuracy of placental growth factor alone or in combination with soluble fms-like tyrosine kinase-1 or maternal factors in detecting preeclampsia in asymptomatic women in the second and third trimesters: a systematic review and meta-analysis

OBJECTIVE

This study aimed to: (1) identify all relevant studies reporting on the diagnostic accuracy of maternal circulating placental growth factor) alone or as a ratio with soluble fms-like tyrosine kinase-1), and of placental growth factor-based models (placental growth factor combined with maternal factors±other biomarkers) in the second or third trimester to predict subsequent development of preeclampsia in asymptomatic women; (2) estimate a hierarchical summary receiver-operating characteristic curve for studies reporting on the same test but different thresholds, gestational ages, and populations; and (3) select the best method to screen for preeclampsia in asymptomatic women during the second and third trimester of pregnancy by comparing the diagnostic accuracy of each method.

DATA SOURCES

A systematic search was performed through MEDLINE, Embase, CENTRAL, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform databases from January 1, 1985 to April 15, 2021.

STUDY ELIGIBILITY CRITERIA

Studies including asymptomatic singleton pregnant women at >18 weeks' gestation with risk of developing preeclampsia were evaluated. We included only cohort or cross-sectional test accuracy studies reporting on preeclampsia outcome, allowing tabulation of 2×2 tables, with follow-up available for >85%, and evaluating performance of placental growth factor alone, soluble fms-like tyrosine kinase-1- placental growth factor ratio, or placental growth factor-based models. The study protocol was registered on the International Prospective Register Of Systematic Reviews (CRD 42020162460).

METHODS

Because of considerable intra- and interstudy heterogeneity, we computed the hierarchical summary receiver-operating characteristic plots and derived diagnostic odds ratios, β, θi, and Λ for each method to compare performances. The quality of the included studies was evaluated by the QUADAS-2 tool.

RESULTS

The search identified 2028 citations, from which we selected 474 studies for detailed assessment of the full texts. Finally, 100 published studies met the eligibility criteria for qualitative and 32 for quantitative syntheses. Twenty-three studies reported on performance of placental growth factor testing for the prediction of preeclampsia in the second trimester, including 16 (with 27 entries) that reported on placental growth factor test alone, 9 (with 19 entries) that reported on the soluble fms-like tyrosine kinase-1-placental growth factor ratio, and 6 (16 entries) that reported on placental growth factor-based models. Fourteen studies reported on performance of placental growth factor testing for the prediction of preeclampsia in the third trimester, including 10 (with 18 entries) that reported on placental growth factor test alone, 8 (with 12 entries) that reported on soluble fms-like tyrosine kinase-1-placental growth factor ratio, and 7 (with 12 entries) that reported on placental growth factor-based models. For the second trimester, Placental growth factor-based models achieved the highest diagnostic odds ratio for the prediction of early preeclampsia in the total population compared with placental growth factor alone and soluble fms-like tyrosine kinase-1-placental growth factor ratio (placental growth factor-based models, 63.20; 95% confidence interval, 37.62-106.16 vs soluble fms-like tyrosine kinase-1-placental growth factor ratio, 6.96; 95% confidence interval, 1.76-27.61 vs placental growth factor alone, 5.62; 95% confidence interval, 3.04-10.38); placental growth factor-based models had higher diagnostic odds ratio than placental growth factor alone for the identification of any-onset preeclampsia in the unselected population (28.45; 95% confidence interval, 13.52-59.85 vs 7.09; 95% confidence interval, 3.74-13.41). For the third trimester, Placental growth factor-based models achieved prediction for any-onset preeclampsia that was significantly better than that of placental growth factor alone but similar to that of soluble fms-like tyrosine kinase-1-placental growth factor ratio (placental growth factor-based models, 27.12; 95% confidence interval, 21.67-33.94 vs placental growth factor alone, 10.31; 95% confidence interval, 7.41-14.35 vs soluble fms-like tyrosine kinase-1-placental growth factor ratio, 14.94; 95% confidence interval, 9.42-23.70).

CONCLUSION

Placental growth factor with maternal factors ± other biomarkers determined in the second trimester achieved the best predictive performance for early preeclampsia in the total population. However, in the third trimester, placental growth factor-based models had predictive performance for any-onset preeclampsia that was better than that of placental growth factor alone but similar to that of soluble fms-like tyrosine kinase-1-placental growth factor ratio. Through this meta-analysis, we have identified a large number of very heterogeneous studies. Therefore, there is an urgent need to develop standardized research using the same models that combine serum placental growth factor with maternal factors ± other biomarkers to accurately predict preeclampsia. Identification of patients at risk might be beneficial for intensive monitoring and timing delivery.

Evolutionary perspective of uteroplacental malperfusion: subjacent insult common to most pregnancy complications

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Relationship between placental pathology and neonatal outcomes

Objective

To evaluate the relationship between maternal vascular malperfusion and acute intrauterine infection/inflammation with neonatal outcomes.

Methods

This was a retrospective study of women with singleton pregnancies who completed placenta pathological examination. The aim was to study the distribution of acute intrauterine infection/inflammation and maternal placental vascular malperfusion among groups with preterm birth and/or rupture of membranes. The relationship between two subtypes of placental pathology and neonatal gestational age, birth weight Z-score, neonatal respiratory distress syndrome, and intraventricular hemorrhage was further explored.

Results

990 pregnant women were divided into four groups, including 651 term, 339 preterm, 113 women with premature rupture of membranes, and 79 with preterm premature rupture of membranes. The incidence of respiratory distress syndrome and intraventricular hemorrhage in four groups were (0.7%, 0.0%, 31.9%, 31.6%, P < 0.001) and (0.9%, 0.9%, 20.0%, 17.7%, P < 0.001), respectively. The incidence of maternal vascular malperfusion and acute intrauterine infection/inflammation were (82.0%, 77.0%, 75.8%, 72.1%, P = 0.06) and (21.9%, 26.5%, 23.1%, 44.3%, P = 0.010), respectively. Acute intrauterine infection/inflammation was associated with shorter gestational age (adjusted difference -4.7 weeks, P < 0.001) and decreased weight (adjusted Z score -2.6, P < 0.001) than those with no lesions in preterm birth. When two subtype placenta lesions co-occurrence, shorter gestational age (adjusted difference -3.0 weeks, P < 0.001) and decreased weight (adjusted Z score -1.8, P < 0.001) were observed in preterm. Consistent findings were observed in preterm births with or without premature rupture of membranes. In addition, acute infection/inflammation and maternal placenta malperfusion alone or in combination were associated with an increased risk of neonatal respiratory distress syndrome (adjusted odds ratio (aOR) 0.8, 1.5, 1.8), but the difference was not statistically significant.

Conclusion

Maternal vascular malperfusion and acute intrauterine infection/inflammation alone or co-occurrence are associated with adverse neonatal outcomes, which may provide new ideas for clinical diagnosis and treatment.

Assessment-based management of placenta-mediated pregnancy complications: Pragmatism until a precision medicine approach evolves

The management of pregnant women with thrombophilia and a history of gestational vascular complications remains debatable. Treatment of the latter is often based on clinical outcome rather than disease mechanism. While the use of venous thromboembolism prophylaxis in pregnancy is recommended for those at increased risk, the ability of anticoagulant and/or antiplatelet agents to lower the risk of placenta-mediated complications in this clinical setting remains controversial. The available guidelines are inconsistent in some situations, which reflects the limited evidence base. This review critically discusses risk assessment models (RAMs) and management strategies of women with thrombophilia and pregnancy complications, using clinical vignettes. RAMs, taking into account obstetric and thrombotic history as well as thrombophilia status, could drive a precision medicine approach, based on disease mechanism, and guide individual therapeutic interventions in high-risk clinical settings.

Preeclampsia at term can be classified into 2 clusters with different clinical characteristics and outcomes based on angiogenic biomarkers in maternal blood

BACKGROUND

An antiangiogenic state has emerged as a mechanism of disease in preeclampsia. Angiogenic biomarkers are used in the risk assessment of this syndrome, particularly of early disease. The role of an antiangiogenic state in late preeclampsia is unclear.

OBJECTIVE

This study aimed to determine the prevalence, characteristics, and clinical significance of angiogenic/antiangiogenic factor abnormalities in women with preeclampsia stratified according to gestational age at delivery.

STUDY DESIGN

Two studies were conducted: (1) a longitudinal nested case-control study comprising women with preeclampsia (n=151) and a control group (n=540); and (2) a case series of patients with preeclampsia (n=452). In patients with preeclampsia, blood was collected at the time of diagnosis. Plasma concentrations of placental growth factor and soluble fms-like tyrosine kinase-1 were determined by enzyme-linked immunosorbent assays. An abnormal angiogenic profile was defined as a plasma ratio of placental growth factor and soluble fms-like tyrosine kinase-1 expressed as a multiple of the median <10th percentile for gestational age based on values derived from the longitudinal study. The proportion of patients diagnosed with preeclampsia who had an abnormal angiogenic profile was determined in the case-series participants and stratified by gestational age at delivery into early (≤34 weeks), intermediate (34.1-36.9 weeks), and term (≥37 weeks) preeclampsia. The demographics, clinical characteristics, and pregnancy outcomes of women with preeclampsia with and without an abnormal angiogenic profile were compared.

RESULTS

The prevalence of an abnormal angiogenic profile was higher in preterm than in term preeclampsia (for early, intermediate, and term in the case-control study: 90%, 100%, and 39%; for the case series: 98%, 80%, and 55%, respectively). Women with preeclampsia at term who had an abnormal angiogenic profile were more frequently nulliparous (57% vs 35%), less likely to smoke (14% vs 26%), at greater risk for maternal (14% vs 5%) or neonatal (7% vs 1%) complications, and more often had placental lesions consistent with maternal vascular malperfusion (42% vs 23%; all, P<.05) than those without an abnormal profile. Women with preeclampsia at term who had a normal angiogenic profile had a higher frequency of chronic hypertension (36% vs 21%) and were more likely to have class ≥2 obesity (41% vs 23%) than those with an abnormal profile (both, P<.05).

CONCLUSION

Patients with early preeclampsia had an abnormal angiogenic profile in virtually all cases, whereas only 50% of women with preeclampsia at term had such abnormalities. The profile of angiogenic biomarkers can be used to classify patients with preeclampsia at term, on the basis of mechanisms of disease, into 2 clusters, which have different demographics, clinical characteristics, and risks of adverse maternal and neonatal outcomes. These findings provide a simple approach to classify preeclampsia at term and have implications for future clinical care and research.

Maternal serum levels of soluble fms-like tyrosine kinase-1 and placental growth factor at 20 and 28 weeks of gestational age and the risk of spontaneous preterm birth

BACKGROUND

Spontaneous preterm birth is the endpoint of multiple different pathophysiological pathways. Fetal growth restriction, assessed by serial ultrasonic fetal biometry, has been shown to predict both preterm and early-term spontaneous labor. The soluble fms-like tyrosine kinase-1 to placental growth factor ratio is predictive of early-term spontaneous labor, but its association with spontaneous preterm birth is unclear.

OBJECTIVE

This study aimed to determine whether maternal serum levels of soluble fms-like tyrosine kinase-1, placental growth factor, and the soluble fms-like tyrosine kinase-1: placental growth factor ratio at 20 and 28 weeks' gestation, and the rate of change in these biomarkers between 20 and 28 weeks were predictive of risk of spontaneous preterm birth.

STUDY DESIGN

The biomarkers were measured in maternal serum at 20- and 28-weeks' gestation in women recruited to a prospective cohort of unselected nulliparous women as part of the Pregnancy Outcome Prediction study in Cambridge, United Kingdom. The risk of spontaneous preterm birth was assessed using Cox regression and competing-risks regression. Associations from Cox regression were quantified by the adjusted hazard ratio for a 1 standard deviation higher level of a given biomarker or a 1 standard deviation increase in the marker between 20 and 28 weeks' gestation. A previously identified risk factor, slow femur length growth, was used as an additional predictor of spontaneous preterm birth for the purpose of risk stratification.

RESULTS

Of the 3763 participants in the analysis, 95 (2.5%) had spontaneous preterm birth and 54 (1.4%) had medically indicated preterm birth. At 20 weeks' gestation, higher levels of soluble fms-like tyrosine kinase-1 and the soluble fms-like tyrosine kinase-1:placental growth factor ratio were associated with reduced risk of spontaneous preterm birth (adjusted hazard ratio [95% confidence interval], 0.75 [0.61-0.92]; P=.006 and 0.71 [0.59-0.87]; P=.0009, respectively). At 28 weeks' gestation, there was no association between either soluble fms-like tyrosine kinase-1 or placental growth factor and the risk of spontaneous preterm birth, but there was a U-shaped relation with the soluble fms-like tyrosine kinase-1:placental growth factor ratio. However, when the biomarkers were quantified as the rate of increase between 20 and 28 weeks' gestation, there were strong positive associations between spontaneous preterm birth and rate of increase in soluble fms-like tyrosine kinase-1 (1.36 [1.13-1.63]; P=.001) and the soluble fms-like tyrosine kinase-1:placental growth factor ratio (1.50 [1.30-1.73]; P<.0001), and a strong negative association with the rate of increase in placental growth factor (0.71 [0.61-0.82]; P<.0001). Women who were in the highest decile of increase in the soluble fms-like tyrosine kinase-1:placental growth factor ratio and the lowest decile of femur length growth between 20 and 28 weeks' gestation had approximately 9-fold risk of spontaneous preterm birth (9.27 [4.21-20.37]; P<.0001). Competing-risks regression yielded similar results.

CONCLUSION

Changing levels of soluble fms-like tyrosine kinase-1 and placental growth factor are indicative of placental dysfunction and are strongly associated with the risk of spontaneous preterm birth, especially when combined with slower fetal femur length growth.

Placental pathology is necessary to understand common pregnancy complications and achieve an improved taxonomy of obstetrical disease

The importance of a fully functioning placenta for a good pregnancy outcome is unquestioned. Loss of function can lead to pregnancy complications and is often detected by a thorough placental pathologic examination. Placental pathology has advanced the science and practice of obstetrics and neonatal-perinatal medicine by classifying diseases according to underlying biology and specific patterns of injury. Many past obstacles have limited the incorporation of placental findings into both clinical studies and day-to-day practice. Limitations have included variability in the nomenclature used to describe placental lesions, a shortage of perinatal pathologists fully competent to analyze placental specimens, and a troubling lack of understanding of placental diagnoses by clinicians. However, the potential use of placental pathology for phenotypic classification, improved understanding of the biology of adverse pregnancy outcomes, the development of treatment and prevention, and patient counseling has never been greater. This review, written partly in response to a recent critique published in a major obstetrics-gynecology journal, reexamines the role of placental pathology by reviewing current concepts of biology; explaining the most recent terminology; emphasizing the usefulness of specific diagnoses for obstetrician-gynecologists, neonatologists, and patients; previewing upcoming changes in recommendations for placental submission; and suggesting future improvements. These improvements should include further consideration of overall healthcare costs, cost-effectiveness, the clinical value added of placental assessment, improvements in placental pathology education and practice, and leveraging of placental pathology to identify new biomarkers of disease and evaluate novel therapies tailored to specific clinicopathologic phenotypes of both women and infants.

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.