Maternal serum alpha-fetoprotein at 12, 22 and 32 weeks' gestation in screening for pre-eclampsia

Alpha-fetoprotein (AFP) is reduced at 36 weeks' gestation in pregnancies destined to deliver small for gestational age infants

Alpha-fetoprotein (AFP) is a protein commonly used to screen for aneuploidy in pregnancy. This study measured circulating AFP in maternal plasma at 36 weeks' gestation preceding diagnosis of term preeclampsia or delivery of a small for gestational age infant (SGA; <10 % birthweight centile) in a case-cohort design (122 SGA; 23 preeclampsia; 182 controls). AFP was significantly reduced in SGA < 5th birthweight centile (n = 51; P = 0.002) but not changed preceding preeclampsia diagnosis. This suggests that AFP is reduced near term preceding SGA diagnosis and may have potential as a biomarker if combined with other candidate molecules.

Correlation between elevated maternal serum alpha-fetoprotein and ischemic placental disease: a retrospective cohort study

BACKGROUND

To evaluate the correlation between elevated maternal serum alpha-fetoprotein (AFP) in the second trimester and ischemic placental disease (IPD).

METHODS

A retrospective cohort study was conducted to analyze the data of 22,574 pregnant women who delivered in the Department of Obstetrics at Hangzhou Women's Hospital from 2018 to 2020, and were screened for maternal serum AFP and free beta-human chorionic gonadotropin (free β-hCG) in the second trimester. The pregnant women were divided into two groups: elevated maternal serum AFP group (n = 334, 1.48%); and normal group (n = 22,240, 98.52%). Mann-Whitney U-test or Chi-square test was used for continuous or categorical data. Modified Poisson regression analysis was used to calculate the relative risk (RR) and 95% confidence interval (CI) of the two groups.

RESULTS

The AFP MoM and free β-hCG MoM in the elevated maternal serum AFP group were higher than the normal group (2.25 vs. 0.98, 1.38 vs. 1.04) and the differences were all statistically significant (all P < .001). Placenta previa, hepatitis B virus carrying status of pregnant women, premature rupture of membranes (PROM), advanced maternal age (≥35 years), increased free β-hCG MoM, female infants, and low birth weight (RR: 2.722, 2.247, 1.769, 1.766, 1.272, 0.624, 2.554 respectively) were the risk factors for adverse maternal pregnancy outcomes in the elevated maternal serum AFP group.

CONCLUSIONS

Maternal serum AFP levels during the second trimester can monitor IPD, such as IUGR, PROM, and placenta previa. Maternal women with high serum AFP levels are more likely to deliver male fetuses and low birth weight infants. Finally, the maternal age (≥35 years) and hepatitis B carriers also increased maternal serum AFP significantly.

Maternal First-Trimester Alpha-Fetoprotein and Placenta-Mediated Pregnancy Complications

BACKGROUND

Maternal serum markers used for trisomy 21 screening are associated with placenta-mediated complications. Recently, there has been a transition from the traditional first-trimester screening (FTS) that included PAPP-A (pregnancy-associated plasma protein-A) and beta-hCG (human chorionic gonadotropin), to the enhanced FTS test, which added first-trimester AFP (alpha-fetoprotein) and PlGF (placental growth factor). However, whether elevated first-trimester AFP has a similar association with placenta-mediated complications to that observed for elevated second-trimester AFP remains unclear. Our objective was to estimate the association of first-trimester AFP with placenta-mediated complications and compare it with the corresponding associations of second-trimester AFP and other first-trimester serum markers.

METHODS

Retrospective population-based cohort study of women who underwent trisomy 21 screening in Ontario, Canada (2013-2019). The association of first-trimester AFP with placenta-mediated complications was estimated and compared with that of the traditional serum markers. The primary outcome was a composite of stillbirth or preterm placental complications (preeclampsia, birthweight less than third centile, or placental abruption).

RESULTS

A total of 244 990 and 96 167 women underwent FTS and enhanced FTS test screening, respectively. All markers were associated with the primary outcome, but the association for elevated first-trimester AFP (adjusted relative risk [aRR], 1.57 [95% CI, 1.37-1.81]) was weaker than that observed for low PAPP-A (aRR, 2.48 [95% CI, 2.2-2.8]), low PlGF (aRR, 2.28 [95% CI, 1.97-2.64]), and elevated second-trimester AFP (aRR, 1.97 [95% CI, 1.81-2.15]). When the models were adjusted for all 4 enhanced FTS test markers, elevated first-trimester AFP was no longer associated with the primary outcome (aRR, 0.77 [95% CI, 0.58-1.02]).

CONCLUSIONS

Unlike second-trimester AFP, elevated first-trimester AFP is not an independent risk factor for placenta-mediated complications.

Potential biomarkers for late-onset and term preeclampsia: A scoping review

Preeclampsia is a progressive, multisystem pregnancy disorder. According to the time of onset or delivery, preeclampsia has been subclassified into early-onset (<34 weeks) and late-onset (≥34 weeks), or preterm (<37 weeks) and term (≥37 weeks). Preterm preeclampsia can be effectively predicted at 11-13 weeks well before onset, and its incidence can be reduced by preventively using low-dose aspirin. However, late-onset and term preeclampsia are more prevalent than early forms and still lack effective predictive and preventive measures. This scoping review aims to systematically identify the evidence of predictive biomarkers reported in late-onset and term preeclampsia. This study was conducted based on the guidance of the Joanna Briggs Institute (JBI) methodology for scoping reviews. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for scoping reviews (PRISMA-ScR) was used to guide the study. The following databases were searched for related studies: PubMed, Web of Science, Scopus, and ProQuest. Search terms contain "preeclampsia," "late-onset," "term," "biomarker," or "marker," and other synonyms combined as appropriate using the Boolean operators "AND" and "OR." The search was restricted to articles published in English from 2012 to August 2022. Publications were selected if study participants were pregnant women and biomarkers were detected in maternal blood or urine samples before late-onset or term preeclampsia diagnosis. The search retrieved 4,257 records, of which 125 studies were included in the final assessment. The results demonstrate that no single molecular biomarker presents sufficient clinical sensitivity and specificity for screening late-onset and term preeclampsia. Multivariable models combining maternal risk factors with biochemical and/or biophysical markers generate higher detection rates, but they need more effective biomarkers and validation data for clinical utility. This review proposes that further research into novel biomarkers for late-onset and term preeclampsia is warranted and important to find strategies to predict this complication. Other critical factors to help identify candidate markers should be considered, such as a consensus on defining preeclampsia subtypes, optimal testing time, and sample types.

High-Risk Pregnancy Is Associated With Increased Alpha-Fetoprotein Concentrations in the Amniotic Fluid and Foal Plasma

This study aimed to determine alpha-fetoprotein (AFP) concentrations in amniotic fluid, plasma of mares and respective foals: carrying normal pregnancies and delivering healthy foals (n = 20; Group 1); carrying apparently normal pregnancies and delivering sick foals (n = 15; Group 2); carrying high-risk pregnancies and delivering sick foals (n = 14; Group 3). High-risk pregnancy was defined by a history of premature udder development/lactation or increased of the combined thickness of the uterus and placenta, or vulvar discharge and/or mares' systemic illness. Sick foals were affected by neonatal encephalopathy, sepsis, prematurity/dysmaturity, or hypoxic-ischemic encephalopathy. Based on histological examination of the chorioallantois, AFP trend was analyzed in pregnancies with pathologic (PFM) and normal fetal membranes (NFM). Concentrations of AFP were measured using a commercially available immunoassay previously validated for horses. Mares' plasma AFP did not change during the last 15-20 days of pregnancy in the three groups, and there was no difference among them. Amniotic fluid AFP was higher in Group 3 (P = .014). Foals' plasma AFP concentration was higher from birth to 72hours in foals of Group 2 and 3 than in healthy ones, and foals of Group 3 had the highest value. The strong association (r = 0.84; P < .0001) between AFP in amniotic fluid and foals' plasma at birth is likely due to the presence of AFP in fetal urine. AFP was higher in pregnancy with PFM than with NFM in mare's plasma at admission (P = .031), amniotic fluid (P = .004), foal's plasma at birth (P = .002), at 24 (P = .005) and at 72 hours of life (P = .004). AFP is higher in pregnancy with histopathological lesions of the chorioallantois providing the evidence of the differences between pregnancy with a normal placental barrier and the more compromised ones. The increased AFP concentration in the amniotic fluid and plasma of high-risk foals suggests upregulation.

Blood biomarkers to predict the onset of pre-eclampsia: A systematic review and meta-analysis

Pre-eclampsia is one of the most common pregnancy complications, and a major cause of fetal and maternal morbidity and mortality globally. Diagnosis currently takes place in the third trimester based on clinical symptoms. This systematic review and meta-analysis sought to determine the blood biomarkers that are associated with pre-eclampsia, and in particular, the biomarkers that could predict pre-eclampsia in early pregnancy. We searched the electronic databases (Medline, Embase, Cochrane Library) from inception up to March 2022. Prospective studies with 1000 or more participants that measured blood biomarkers to predict or diagnose pre-eclampsia have been included in this systematic review. Biomarkers' measurements were considered from the first up to the third trimester, but not during labor. Data concerning pre-eclampsia, biomarker measurements and study characteristics were extracted. Meta-analysis was performed when possible. We found a total of 43 studies (assessing 62 different biomarkers in 18,170 pregnancies, have been included in this systematic review, and a total of 6 studies (assessing 2 biomarkers have been included in the meta-analysis). Statistical analysis was performed for PlGF and sFlt-1. Mean difference in PlGF levels between pre-eclampsia and healthy pregnancies, appear to increase as the pregnancy progresses. Results of sFlt-1 meta-analysis were inconclusive. No significant publication bias was identified. This is the most comprehensive and up to date systematic review and meta-analysis on this important topic on blood biomarkers for the early prediction of pre-eclampsia. Further This research highlights the urgent needed for further discovery research to identify blood biomarkers that could predict the development of pre-eclampsia.

Modified multiple marker aneuploidy screening as a primary screening test for preeclampsia

Background

Abnormal levels of maternal biochemical markers used in multiple marker aneuploidy screening have been associated with adverse pregnancy outcomes. This study aims to assess if a combination of maternal characteristics and biochemical markers in the first and second trimesters can be used to screen for preeclampsia (PE). The secondary aim was to assess this combination in identifying pregnancies at risk for gestational hypertension and preterm birth.

Methods

This case-control study used information on maternal characteristics and residual blood samples from pregnant women who have undergone multiple marker aneuploidy screening. The median multiple of the median (MoM) of first and second trimester biochemical markers in cases (women with PE, gestational hypertension and preterm birth) and controls were compared. Biochemical markers included pregnancy-associated plasma protein A (PAPP-A), placental growth factor (PlGF), human chorionic gonadotropin (hCG), alpha feto-protein (AFP), unconjugated estriol (uE3) and Inhibin A. Logistic regression analysis was used to estimate screening performance using different marker combinations. Screening performance was defined as detection rate (DR) and false positive rate (FPR). Preterm and early-onset preeclampsia PE were defined as women with PE who delivered at < 37 and < 34 weeks of gestation, respectively.

Results

There were 147 pregnancies with PE (81 term, 49 preterm and 17 early-onset), 295 with gestational hypertension, and 166 preterm birth. Compared to controls, PE cases had significantly lower median MoM of PAPP-A (0.77 vs 1.10, p < 0.0001), PlGF (0.76 vs 1.01, p < 0.0001) and free-β hCG (0.81 vs. 0.98, p < 0.001) in the first trimester along with PAPP-A (0.82 vs 0.99, p < 0.01) and PlGF (0.75 vs 1.02, p < 0.0001) in the second trimester. The lowest first trimester PAPP-A, PlGF and free β-hCG were seen in those with preterm and early-onset PE. At a 20% FPR, 67% of preterm and 76% of early-onset PE cases can be predicted using a combination of maternal characteristics with PAPP-A and PlGF in the first trimester. The corresponding DR was 58% for gestational hypertension and 36% for preterm birth cases.

Conclusions

Maternal characteristics with first trimester PAPP-A and PlGF measured for aneuploidy screening provided reasonable accuracy in identifying women at risk of developing early onset PE, allowing triage of high-risk women for further investigation and risk-reducing therapy. This combination was less accurate in predicting women who have gestational hypertension or preterm birth.

Effect of adenomyosis on adverse obstetrical outcomes in twin pregnancies achieved with assisted reproductive technology

The incidence of twin pregnancy with adenomyosis (AD) is increasing due to advanced maternal age and infertility treatment. We retrospectively analysed the data of 45 dichorionic twin pregnancies complicated with AD in contrast to a control group of dichorionic twin pregnancies without AD (n = 130). Compared with those in the control group, the AD group had a higher overall foetal loss rate (8.9% vs. 0.8%; adjusted p = .031; odds ratio (OR), 13.6; 95% confidence interval (CI), 1.27-146.3), higher early preterm delivery rate (20% vs. 6.9%; adjusted p = .007; OR, 4.22; 95% CI, 1.47-12.13) and higher rate of hypertensive disorders of pregnancy (26.7% vs. 7.7%; adjusted p = .005; OR, 3.94; 95% CI, 1.5-10.2). Patients in the AD group were significantly more likely to require transfusion during or after delivery (17.8% vs. 5.4%; p = .026) and have smaller babies (2168 g vs. 2399 g; p = .004) compared with those in the control group. This is the first study to report that twin pregnancies with AD may be treated as high-risk for placental dysfunction and may need closer monitoring during pregnancy.Impact StatementWhat is already known on this subject? The incidence of twin pregnancy with adenomyosis (AD) is increasing due to advanced maternal age and infertility treatment. However, there are very few studies on the effect of AD on pregnancy outcomes.What the results of this study add? This is the first study to report that twin pregnancies with AD have higher rates of early preterm delivery, hypertensive disorders of pregnancy, and transfusion compared to controls.What the implications are of these findings for clinical practice and/or further research? The results of this study can be used in counselling twin pregnancies with AD. Further research is needed to confirm the current findings.

Second trimester maternal serum D-dimer combined with alpha-fetoprotein and free β-subunit of human chorionic gonadotropin predict hypertensive disorders of pregnancy: a systematic review and retrospective case-control study

Background

This study investigated whether maternal serum D-dimer (DD) alone or DD combined with alpha-fetoprotein (AFP) and free β-subunit of human chorionic gonadotropin (free β-hCG) in the second trimester could be used to predict hypertensive disorders of pregnancy (HDP).

Materials and methods

In this retrospective case–control study, the data of gravidas patients who delivered at hospital were divided into the following groups: control (n = 136), gestational hypertension (GH, n = 126), preeclampsia (PE, n = 53), and severe preeclampsia (SPE, n = 41). Receiver operator characteristic (ROC) curves were used to evaluate the diagnostic value of maternal serum DD, AFP, and free β-hCG levels for HDP.

Results

DD levels of the GH, PE, and SPE groups were significantly higher than that of the control group (P < 0.001). The order of effectiveness for models predicting HDP was as follows: DD + AFP + free β-hCG > DD > DD + AFP > DD + free β-hCG > AFP + free β-hCG > AFP > free β-hCG. For predicting different types of HDP, DD alone had the best diagnostic value for SPE, followed by PE and GH. DD alone had a sensitivity of 100% with a 0% false negative rate and had the highest positive likelihood ratio (+ LR) for SPE. DD alone in combination with AFP alone, free β-hCG alone and AFP + free β-hCG could reduce false positive rate and improve + LR.

Conclusion

DD is possible the best individual predictive marker for predicting HDP. Levels of DD alone in the second trimester were positively correlated with the progression of elevated blood pressure in the third trimester, demonstrating the predicting the occurrence of HDP. The risk calculation model constructed with DD + free β-hCG + AFP had the greatest diagnostic value for SPE.

Pregnancy outcomes of women with elevated second-trimester maternal serum alpha-fetoprotein

OBJECTIVE

The aim of this study was to investigate the overall distribution of pregnancy outcomes in women with elevated second-trimester maternal serum alpha-fetoprotein (MS-AFP), and to determine the risk of adverse pregnancy outcomes (APOs) by MS-AFP level.

MATERIALS AND METHODS

We retrospectively analyzed the clinical data of 429 women with elevated MS-AFP (≥2.5 multiple of the median (MOM)) and 1555 women with normal MS-AFP (0.5-2.49MOM) from a total of 46,741 prenatally screened singleton pregnant women. The overall distribution of APOs of the two groups, the risk of APOs by MS-AFP level, and the predictive value of elevated MS-AFP to APOs were analyzed.

RESULTS

The incidence rate of APOs in elevated MS-AFP group was significantly higher than that in normal MS-AFP group (42.89 vs. 8.23%). In elevated MS-AFP group, the top three APOs, in term of incidence rate, were structural fetal abnormalities (7.93%), spontaneous abortion (7.46%) and preterm birth (7.23%); regarding to the risk, the top three APOs were stillbirth, spontaneous abortion and early-onset preeclampsia (odds ratio 35.98, 20.81 and 8.58 respectively). For structural fetal abnormalities, MS-AFP had predictive values for fetal open neural tube defects (ONTDs), gastroschisis and multiple malformations.

CONCLUSION

Elevated MS-AFP is associated with increased risks of APOs. ONTDs complicate merely a small proportion of pregnancies with elevated MS-AFP, and the rest of them have high risks of obstetric complications. MS-AFP can help to identify these women at high risk of APOs in earlier second-trimester.

First-Trimester Preterm Preeclampsia Screening in Nulliparous Women: The Great Obstetrical Syndrome (GOS) Study

OBJECTIVES

To estimate the ability of a combination of first-trimester markers to predict preterm preeclampsia in nulliparous women.

METHODS

We conducted a prospective cohort study of nulliparous women with singleton gestations, recruited between 11⁰ and 13⁶ weeks gestation. Data on the following were collected: maternal age; ethnicity; chronic diseases; use of fertility treatment; body mass index; mean arterial blood pressure (MAP); serum levels of pregnancy-associated plasma protein A (PAPP-A), placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), alpha fetoprotein (AFP), free beta human chorionic gonadotropin (ß-hCG); and mean uterine artery pulsatility index (UtA-PI). We constructed a proportional hazard model for the prediction of preterm preeclampsia selected based on the Akaike information criterion. A receiver operating characteristic curve was created with the predicted risk from the final model. Our primary outcome was preterm preeclampsia and our secondary outcome was a composite of preeclampsia, small for gestational age, intrauterine death, and preterm birth.

RESULTS

Among 4659 nulliparous women with singleton gestations, our final model included 4 variables: MAP MoM, log₁₀PlGF MoM, log₁₀AFP MoM and log₁₀UtA-PI MoM. We obtained an area under the curve of 0.84 (95% CI 0.75-0.93) with a detection rate of preterm preeclampsia of 55% (95% CI 37%-73%) and a false-positive rate of 10%. Using a risk cut-off with a false-positive rate of 10%, the positive predictive value for our composite outcome was 33% (95% CI 29%-37%).

CONCLUSIONS

The combination of MAP, maternal serum PlGF and AFP, and UtA-PI are useful to identify nulliparous women at high risk of preterm preeclampsia but also at high risk of other great obstetrical syndromes.

First-trimester maternal serum alpha-fetoprotein is not a good predictor for adverse pregnancy outcomes: a retrospective study of 3325 cases

Background

It is well known that second-trimester maternal serum alpha-fetoprotein (MS-AFP) is a predictor for adverse pregnancy outcomes (APOs), such as preterm birth, stillbirth, preeclampsia and small for gestational age (SGA). However, it is unknown whether first-trimester MS-AFP is also predictive of APOs.

Methods

We retrospectively reviewed the data on the first-trimester MS-AFP levels and pregnancy outcomes of 3325 singleton pregnant women. The cutoff value of 2.5 multiple of the median (MoM) was used to evaluate the risks of APOs regarding MS-AFP. The receiver operating characteristic (ROC) curves were used to evaluate the predictive efficiencies of MS-AFP to these disorders.

Results

A total of 181 pregnancies resulted in preterm birth, 32 in stillbirth, 81 in preeclampsia, and 362 in SGA. Compared to women with MS-AFP < 2.5MoM, those with MS-AFP ≥ 2.5MoM had increased risks (odds ratio, 95% confidence interval) of preterm birth (2.53, 1.65~3.88), preeclampsia (3.05, 1.71~5.43) and SGA (1.90, 1.34~2.69), and had an earlier distribution of gestational weeks at delivery (P = 0.004) and a lower distribution of neonatal birth weights (P = 0.000), but the actual between-group differences were minuscule. The areas under ROC curves were 0.572 (P = 0.001), 0.579 (P = 0.015) and 0.565 (P = 0.000) for preterm birth, preeclampsia and SGA, respectively. Subdivisions for the disorders did not obviously improve the performances of MS-AFP.

Conclusions

Elevated first-trimester MS-AFP is associated with increased risk of preterm birth, preeclampsia and SGA. However, the predictive efficiencies were low and it is not a good predictor for these APOs.

A rat model of placental inflammation explains the unexplained elevated maternal serum alpha-fetoprotein associated with adverse pregnancy outcomes

AIM

It has been reported in numerous studies that elevated maternal serum alpha-fetoprotein (MS-AFP) is associated with adverse pregnancy outcomes (APO), such as pre-eclampsia, stillbirth, preterm birth and fetal growth restriction. However, the mechanism linking elevated MS-AFP and APO is obscure. In this study, we tried to explore the mechanism by using pregnant rats.

METHODS

Lipopolysaccharide (LPS) was used to induce placental inflammation in pregnant rats. Maternal serum and placental inflammatory cytokines and placental morphology were used to assess the level of placental inflammation. The incidences of APO and the levels of MS-AFP were evaluated. The expressions of alpha-fetoprotein (AFP) in the related organs and fetal serum AFP levels were detected.

RESULTS

Compared to saline-treated pregnant rats, LPS led to elevated maternal serum and placental inflammatory cytokines and a higher rate of placental inflammation. Lipopolysaccharide resulted in the features of APO and at the same time elevated MS-AFP. Maternal serum alpha-fetoprotein levels were significantly correlated to the evaluation parameters of APO. Lipopolysaccharide did not increase the expressions of AFP in fetal liver, maternal liver and placenta, but reduced the fetal serum AFP levels.

CONCLUSION

The phenomenon that elevated MS-AFP is associated with APO, which has been reported in human pregnancies, is observed in our rat model. Placental inflammation can be the potential cause linking the two manifestations together. Although the source of elevated MS-AFP is not identified, fetal blood circulation is suspected. Our study may provide an animal model for the future studies on this subject.

A proteomic clock of human pregnancy

BACKGROUND

Early detection of maladaptive processes underlying pregnancy-related pathologies is desirable because it will enable targeted interventions ahead of clinical manifestations. The quantitative analysis of plasma proteins features prominently among molecular approaches used to detect deviations from normal pregnancy. However, derivation of proteomic signatures sufficiently predictive of pregnancy-related outcomes has been challenging. An important obstacle hindering such efforts were limitations in assay technology, which prevented the broad examination of the plasma proteome.

OBJECTIVE

The recent availability of a highly multiplexed platform affording the simultaneous measurement of 1310 plasma proteins opens the door for a more explorative approach. The major aim of this study was to examine whether analysis of plasma collected during gestation of term pregnancy would allow identifying a set of proteins that tightly track gestational age. Establishing precisely timed plasma proteomic changes during term pregnancy is a critical step in identifying deviations from regular patterns caused by fetal and maternal maladaptations. A second aim was to gain insight into functional attributes of identified proteins and link such attributes to relevant immunological changes.

STUDY DESIGN

Pregnant women participated in this longitudinal study. In 2 subsequent sets of 21 (training cohort) and 10 (validation cohort) women, specific blood specimens were collected during the first (7-14 weeks), second (15-20 weeks), and third (24-32 weeks) trimesters and 6 weeks postpartum for analysis with a highly multiplexed aptamer-based platform. An elastic net algorithm was applied to infer a proteomic model predicting gestational age. A bootstrapping procedure and piecewise regression analysis was used to extract the minimum number of proteins required for predicting gestational age without compromising predictive power. Gene ontology analysis was applied to infer enrichment of molecular functions among proteins included in the proteomic model. Changes in abundance of proteins with such functions were linked to immune features predictive of gestational age at the time of sampling in pregnancies delivering at term.

RESULTS

An independently validated model consisting of 74 proteins strongly predicted gestational age (P = 3.8 × 10^-14, R = 0.97). The model could be reduced to 8 proteins without losing its predictive power (P = 1.7 × 10^-3, R = 0.91). The 3 top ranked proteins were glypican 3, chorionic somatomammotropin hormone, and granulins. Proteins activating the Janus kinase and signal transducer and activator of transcription pathway were enriched in the proteomic model, chorionic somatomammotropin hormone being the top-ranked protein. Abundance of chorionic somatomammotropin hormone strongly correlated with signal transducer and activator of transcription-5 signaling activity in CD4 T cells, the endogenous cell-signaling event most predictive of gestational age.

CONCLUSION

Results indicate that precisely timed changes in the plasma proteome during term pregnancy mirror a proteomic clock. Importantly, the combined use of several plasma proteins was required for accurate prediction. The exciting promise of such a clock is that deviations from its regular chronological profile may assist in the early diagnoses of pregnancy-related pathologies, and point to underlying pathophysiology. Functional analysis of the proteomic model generated the novel hypothesis that chrionic somatomammotropin hormone may critically regulate T-cell function during pregnancy.

Early Detection of Preeclampsia Using Circulating Small non-coding RNA

Preeclampsia is one of the most dangerous pregnancy complications, and the leading cause of maternal and perinatal mortality and morbidity. Although the clinical symptoms appear late, its origin is early, and hence detection is feasible already at the first trimester. In the current study, we investigated the abundance of circulating small non-coding RNAs in the plasma of pregnant women in their first trimester, seeking transcripts that best separate the preeclampsia samples from those of healthy pregnant women. To this end, we performed small non-coding RNAs sequencing of 75 preeclampsia and control samples, and identified 25 transcripts that were differentially expressed between preeclampsia and the control groups. Furthermore, we utilized those transcripts and created a pipeline for a supervised classification of preeclampsia. Our pipeline generates a logistic regression model using a 5-fold cross validation on numerous random partitions into training and blind test sets. Using this classification procedure, we achieved an average AUC value of 0.86. These findings suggest the predictive value of circulating small non-coding RNA in the first trimester, warranting further examination, and lay the foundation for producing a novel early non-invasive diagnostic tool for preeclampsia, which could reduce the life-threatening risk for both the mother and fetus.

First-trimester screening for early and late preeclampsia using maternal characteristics, biomarkers, and estimated placental volume

BACKGROUND

Preeclampsia is a major cause of perinatal morbidity and mortality. First-trimester screening has been shown to be effective in selecting patients at an increased risk for preeclampsia in some studies.

OBJECTIVE

We sought to evaluate the feasibility of screening for preeclampsia in the first trimester based on maternal characteristics, medical history, biomarkers, and placental volume.

STUDY DESIGN

This is a prospective observational nonintervention cohort study in an unselected US population. Patients who presented for an ultrasound examination between 11-13+6 weeks' gestation were included. The following parameters were assessed and were used to calculate the risk of preeclampsia: maternal characteristics (demographic, anthropometric, and medical history), maternal biomarkers (mean arterial pressure, uterine artery pulsatility index, placental growth factor, pregnancy-associated plasma protein A, and maternal serum alpha-fetoprotein), and estimated placental volume. After delivery, medical records were searched for the diagnosis of preeclampsia. Detection rates for early-onset preeclampsia (<34 weeks' gestation) and later-onset preeclampsia (≥34 weeks' gestation) for 5% and 10% false-positive rates using various combinations of markers were calculated.

RESULTS

We screened 1288 patients of whom 1068 (82.99%) were available for analysis. In all, 46 (4.3%) developed preeclampsia, with 13 (1.22%) having early-onset preeclampsia and 33 (3.09%) having late-onset preeclampsia. Using maternal characteristics, serum biomarkers, and uterine artery pulsatility index, the detection rate of early-onset preeclampsia for either 5% or 10% false-positive rate was 85%. With the same protocol, the detection rates for preeclampsia with delivery <37 weeks were 52% and 60% for 5% and 10% false-positive rates, respectively. Based on maternal characteristics, the detection rates for late-onset preeclampsia were 15% and 48% for 5% and 10%, while for preeclampsia at ≥37 weeks' gestation the detection rates were 24% and 43%, respectively. The detection rates for late-onset preeclampsia and preeclampsia with delivery at >37 weeks' gestation were not improved by the addition of biomarkers.

CONCLUSION

Screening for preeclampsia at 11-13+6 weeks' gestation using maternal characteristics and biomarkers is associated with a high detection rate for a low false-positive rate. Screening for late-onset preeclampsia yields a much poorer performance. In this study the utility of estimated placental volume and mean arterial pressure was limited but larger studies are needed to ultimately determine the effectiveness of these markers.

Placenta-derived exosomes: potential biomarkers of preeclampsia

Preeclampsia remains a leading cause of maternal and fetal mortality, due to ineffective treatment and diagnostic strategies, compounded by the lack of clarity on the etiology of the disorder. Although several clinical and biological markers of preeclampsia have been evaluated, they have proven to be ineffective in providing a definitive diagnosis during the various stages of the disorder. Exosomes have emerged as ideal biomarkers of pathological states, such as cancer, and have more recently gained interest in pregnancy-related complications, due to their role in cellular communication in normal and complicated pregnancies. This occurs as a result of the specific placenta-derived exosomal molecular cargo, which may be involved in normal pregnancy-associated immunological events, such as the maintenance of maternal-fetal tolerance. This review provides perspectives on placenta-derived exosomes as possible biomarkers for the diagnosis/prognosis of preeclampsia. Using keywords, online databases were searched to identify relevant publications to review the potential use of placenta-derived exosomes as biomarkers of preeclampsia.

Pregnancy outcomes regarding maternal serum AFP value in second trimester screening

AIM

The aim of this study was to evaluate the predictive value of α-fetoprotein in maternal serum (MS-AFP) as a marker for diverse pregnancy outcomes.

METHODS

The study was based on pregnancy and delivery data from 5520 women between 1999 and 2014 at University Hospital of Zurich (UHZ).

INCLUSION CRITERIA

both MS-AFP and pregnancy outcome were known for the same pregnancy. Pregnancy outcomes and characteristics such as fetal malformation, intrauterine fetal death (IUFD) and intrauterine growth retardation as well as maternal age, weight before pregnancy, gestational age (GA) at delivery, newborn weight, length and head circumference were analyzed with respect to the MS-AFP value. MS-AFP value was categorized into three groups: elevated MS-AFP>2.5 multiples of the median (MoM), normal 0.5-2.49 MoM and decreased <0.5 MoM.

RESULTS

Newborn weight (g) and length (cm) were significantly lower in the elevated MS-AFP (P<0.001) group, and infants had 1 week lower GA at delivery (P<0.05). In the group of elevated MS-AFP (n=46), 26.1% of pregnancies were significantly related to adverse pregnancy outcomes, such as fetal malformations, fetuses small for gestational age (SGA) and IUFD. Adverse pregnancy outcomes of 5.6% were registered in the group of normal MS-AFP and 7.3% in the group of low MS-AFP (P<0.05).

CONCLUSION

MS-AFP level in the second trimester is still an important indicator of fetal surface malformations; however, ultrasound still outweighs as a screening method. Nevertheless, pregnant women with elevated MS-AFP values and with no sonographically detected fetal malformations should additionally receive the third trimester ultrasound examination to exclude other possible complications of pregnancy.

Performance of first trimester biochemical markers and mean arterial pressure in prediction of early-onset pre-eclampsia

OBJECTIVE

To develop a predictive risk model for early-onset pre-eclampsia (EO-PE) using maternal characteristics, combined screening markers, previously reported biomarkers for PE and mean arterial pressure (MAP).

METHODS

This retrospective study was conducted at Oulu University hospital between 2006 and 2010. Maternal serum from first trimester combined screening was further analyzed for alpha fetoprotein (AFP), placental growth factor (PlGF), soluble tumor necrosis factor receptor-1 (sTNFR1), retinol binding protein-4 (RBP4), a disintegrin and metalloprotease-12 (ADAM12), soluble P-selectin (sP-selectin), follistatin like-3 (FSTL3), adiponectin, angiopoietin-2 (Ang-2) and sex hormone binding globulin (SHBG). First, the training sample set with 29 cases of EO-PE and 652 controls was developed to study whether these biomarkers separately or in combination with prior risk (maternal characteristics, first trimester pregnancy associated plasma protein-A (PAPP-A) and free beta human chorionic gonadotrophin (fβ-hCG)) could be used to predict the development of EO-PE. Second, the developed risk models were validated with a test sample set of 42 EO-PE and 141 control subjects. For the test set MAP data was also available.

RESULTS

Single marker statistically significant (ANOVA p<0.05) changes between control and EO-PE pregnancies were observed with AFP, RBP4 and sTNFR1 with both training and test sample sets. Based on the test sample set performances, the best detection rate, 47% for a 10% false positive rate, was achieved with PlGF and sTNFR1 added with prior risk and MAP.

CONCLUSION

Based on our results, the best first trimester biomarkers to predict the subsequent EO-PE were AFP, PlGF, RBP4 and sTNFR1. The risk models that performed best for the prediction of EO-PE included prior risk, MAP, sTNFR1 and AFP or PlGF or RBP4.