Pregnancy-associated Plasma Protein Research Articles

Machine Learning Algorithms Versus Classical Regression Models in Pre-Eclampsia Prediction: A Systematic Review.

Machine learning (ML) approaches are an emerging alternative for healthcare risk prediction. We aimed to synthesise the literature on ML and classical regression studies exploring potential prognostic factors and to compare prediction performance for pre-eclampsia. From 9382 studies retrieved, 82 were included. Sixty-six publications exclusively reported eighty-four classical regression models to predict variable timing of onset of pre-eclampsia. Another six publications reported purely ML algorithms, whilst another 10 publications reported ML algorithms and classical regression models in the same sample with 8 of 10 findings that ML algorithms outperformed classical regression models. The most frequent prognostic factors were age, pre-pregnancy body mass index, chronic medical conditions, parity, prior history of pre-eclampsia, mean arterial pressure, uterine artery pulsatility index, placental growth factor, and pregnancy-associated plasma protein A. Top performing ML algorithms were random forest (area under the curve (AUC) = 0.94, 95% confidence interval (CI) 0.91-0.96) and extreme gradient boosting (AUC = 0.92, 95% CI 0.90-0.94). The competing risk model had similar performance (AUC = 0.92, 95% CI 0.91-0.92) compared with a neural network. Calibration performance was not reported in the majority of publications. ML algorithms had better performance compared to classical regression models in pre-eclampsia prediction. Random forest and boosting-type algorithms had the best prediction performance. Further research should focus on comparing ML algorithms to classical regression models using the same samples and evaluation metrics to gain insight into their performance. External validation of ML algorithms is warranted to gain insights into their generalisability.

Serum Hydroxysteroid (17beta) dehydrogenase 1 concentration in pregnant women correlates with pregnancy-associated plasma protein a but does not serve as an independent marker for preeclampsia.

Hydroxysteroid (17beta) dehydrogenase 1 (HSD17B1) is a steroid synthetic enzyme expressed in ovarian granulosa cells and placental syncytiotrophoblasts. Here, HSD17B1 serum concentration was measured with a validated immuno assay during pregnancy at three time points (12-14, 18-20 and 26-28weeks of gestation). The concentration increased 2.5-fold (p < 0.0001) and 1.7-fold (p = 0.0019) during the follow-up period for control women and women who later developed preeclampsia (PE), respectively, and a significant difference was observed at weeks 26-28 (p = 0.0266). HSD17B1 concentration at all the three time points positively correlated with serum PAPPA measured at the first time point (first time point r = 0.38, p = 1.1x10-10; second time point r = 0.27, p = 5.9x10-6 and third timepoint r = 0.26, p = 2.3x10-5). No correlation was observed between HSD17B1 and placental growth factor (PLGF). Serum HSD17B1, furthermore, negatively correlated with the mother's weight and body mass index (BMI), mirroring the pattern observed for PAPPA. The univariable logistic regression identified a weak association between HSD17B1 at 26-28weeks and later development of PE (P = 0.04). Also, the best multivariable model obtained using penalized logistic regression with stable iterative variable selection at 26-28weeks included HSD17B1, together with PLGF, PAPPA and the mother's BMI. While the area under the ROC curve of the model was higher than that of the adjusted PLGF, the difference was not statistically significant. In summary, the serum concentration of HSD17B1 correlated with PAPPA, another protein expressed in syncytiotrophoblasts, and with mother's weight and BMI but could not be considered as an independent marker for PE.

Prospective Validation of First-Trimester Screening for Preterm Preeclampsia in Nulliparous Women (PREDICTION Study).

Fetal Medicine Foundation (FMF) studies suggest that preterm preeclampsia can be predicted in the first trimester by combining biophysical, biochemical, and ultrasound markers and prevented using aspirin. We aimed to evaluate the FMF preterm preeclampsia screening test in nulliparous women. We conducted a prospective multicenter cohort study of nulliparous women recruited at 11 to 14 weeks. Maternal characteristics, mean arterial blood pressure, PAPP-A (pregnancy-associated plasma protein A), PlGF (placental growth factor) in maternal blood, and uterine artery pulsatility index were collected at recruitment. The risk of preterm preeclampsia was calculated by a third party blinded to pregnancy outcomes. Receiver operating characteristic curves were used to estimate the detection rate (sensitivity) and the false-positive rate (1-specificity) for preterm (<37 weeks) and for early-onset (<34 weeks) preeclampsia according to the FMF screening test and according to the American College of Obstetricians and Gynecologists criteria. We recruited 7554 participants including 7325 (97%) who remained eligible after 20 weeks of which 65 (0.9%) developed preterm preeclampsia, and 22 (0.3%) developed early-onset preeclampsia. Using the FMF algorithm (cutoff of ≥1 in 110 for preterm preeclampsia), the detection rate was 63.1% for preterm preeclampsia and 77.3% for early-onset preeclampsia at a false-positive rate of 15.8%. Using the American College of Obstetricians and Gynecologists criteria, the equivalent detection rates would have been 61.5% and 59.1%, respectively, for a false-positive rate of 34.3%. The first-trimester FMF preeclampsia screening test predicts two-thirds of preterm preeclampsia and three-quarters of early-onset preeclampsia in nulliparous women, with a false-positive rate of ≈16%. URL: https://www.clinicaltrials.gov; Unique identifier: NCT02189148.

Association between aneuploidy screening analytes and adverse outcomes in twin gestations.

To evaluate associations between serum analytes used for genetic screening and obstetric complications among twin pregnancies. This cohort included twins delivered at a tertiary care hospital from 2009 to 2017. Abnormal levels of pregnancy associated plasma protein (PAPP-A), first and second trimester human chorionic gonadotropin (hCG), alpha fetoprotein (AFP), estriol, and inhibin, reported as multiples of the median (MoM), were defined as <5 %ile or >95 %ile for our cohort. Associations between abnormal analytes and preterm delivery, small for gestational age, and pregnancy-associated hypertension were calculated using Fisher's exact test. A total of 357 dichorionic/diamniotic and 123 monochorionic/diamniotic twins were included. Among dichorionic/diamniotic twins, elevated AFP (>3.70 MoM) was associated with increased preterm delivery <34weeks (44.4 vs. 16.5 %, p=0.007), while elevated inhibin (>4.95 MoM) was associated with increased preterm delivery<37weeks (94.1 vs. 58.8 %, p=0.004). For monochorionic/diamniotic twins, elevated inhibin (>6.34 MoM) was associated increased preterm delivery <34weeks (66.7 vs. 24.8 %, p=0.04) and hypertension (66.7 vs. 21.4 %, p=0.03). Selected abnormal analyte levels were associated with increased rates of adverse outcomes in twin pregnancies, which differed by chorionicity. Our findings assist providers in interpreting abnormal analyte levels in twin pregnancies and may help to identify those at increased risk for adverse outcomes.

Biomarkers for Early Prediction and Management of Preeclampsia: A Comprehensive Review.

Preeclampsia is a common complication of pregnancy. It is a multi-organ disorder that remains one of the main causes of maternal morbidity and mortality. Additionally, preeclampsia leads to many complications that can occur in the fetus or newborn. Preeclampsia occurs in about 1 in 20 pregnant women. This review focuses on the prediction of preeclampsia in women, using various biomarkers, in particular, a factor combining the use of soluble FMS-like tyrosinokinase-1 (sFlt-1) and placental growth factor (PlGF). A low value of the sFlt-1/PlGF ratio rules out the occurrence of preeclampsia within 4 weeks of the test result, and its high value predicts the occurrence of preeclampsia within even 1 week. The review also highlights other factors, such as pregnancy-associated plasma protein A, placental protein 13, disintegrin and metalloprotease 12, ß-human chorionic gonadotropin, inhibin-A, soluble endoglin, nitric oxide, and growth differentiation factor 15. Biomarker testing offers reliable and cost-effective screening methods for early detection, prognosis, and monitoring of preeclampsia. Early diagnosis in groups of women at high risk for preeclampsia allows for quick intervention, preventing the undesirable effects of preeclampsia. However, further research is needed to validate and optimize the use of biomarkers for more accurate prediction and diagnosis. This article aims to review the role of biomarkers, including the sFlt1/PlGF ratio, in the prognosis and management of preeclampsia.

Abstract P357: Health Behaviors in Early Pregnancy Are Associated With Mid-Pregnancy Biomarkers of Placental Health and Function

Introduction: Placental blood biomarkers are dysregulated in adverse pregnancy outcomes (APO). While health behaviors are associated with APO risk, it is not well-characterized whether health behaviors impact placental blood biomarkers. Thus, we examined the associations between health behaviors and placental biomarkers of angiogenesis in mid-pregnancy. Hypothesis: Pregnant people engaging in healthier behaviors in the 1 st trimester would demonstrate more favorable 2 nd trimester concentrations of placental biomarkers. Methods: Data from 2,078 participants with available analytes from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be were included, representing an enriched sample of APO (preterm birth, preeclampsia/eclampsia, small-for-gestational age, or stillbirth; n=1,284) and 12% of those without these diagnoses (n=794). Health behaviors of physical activity, sleep, smoking, and diet assessed in the 1 st trimester were scored from 0-100 according to the Life’s Essential 8 algorithm; a higher score is more favorable. Biomarkers assayed included total endoglin, pregnancy-associated plasma protein A (PAPP-A), vascular endothelial growth factor, placental growth factor, and soluble FMS-like tyrosine 1. The association between health behaviors and each biomarker was examined using linear (continuous) or logistic (odds of concentration below multiple of the median [MoM] cut point) regression adjusted for demographics, BMI, resilience (Connor-Davidson Scale), and perceived discrimination (Krieger Racism Scale) using a backwards stepwise approach; analyses were repeated stratified by APO status. Bonferroni-corrected significance was p&lt;0.001. Results: The overall APO rate in this enriched sample was 62%; this was significantly lower in those with ≥150 min/week compared with no physical activity (58% vs 66%, p=0.04). Lower (worse) smoking score was associated with lower (adverse) PAPP-A concentration in those who developed APO (p&lt;0.001). Higher physical activity score (healthier) was associated with lower PAPP-A concentration (adverse) regardless of APO occurrence; for every 10-point higher physical activity score, odds of PAPP-A &lt; 0.3 MoM increased 10% (OR 1.10; 95% CI 1.05, 1.16). No associations were observed between the other health behaviors and biomarkers. Conclusions: Higher levels of physical activity were associated with lower APO occurrence. In contrast, PAPP-A concentrations were lower in those with higher physical activity regardless of pregnancy outcome. Lower 2 nd trimester PAPP-A was observed in those with higher smoking exposure who developed APO. Our findings support prior work demonstrating lower risk of APO with more physical activity in pregnancy, but also indicate that PAPP-A concentrations may be sensitive to physical activity and smoking. Further work to elucidate the mechanisms of these associations is warranted.

Unveiling the Role of Pregnancy-Associated Plasma Protein A (PAPP-A) in Pregnancy-Associated Breast Cancer: A Comprehensive Review.

Pregnancy-associated breast cancer (PABC) presents unique challenges due to its occurrence during or shortly after pregnancy. Pregnancy-associated plasma protein A (PAPP-A) has emerged as a potential biomarker and regulator in PABC. This comprehensive review examines the role of PAPP-A in PABC, highlighting its involvement in tissue remodeling and cancer progression. Molecular mechanisms linking PAPP-A to breast cancer, including signaling pathways and interactions with other molecules, are explored. The review also discusses the diagnostic and therapeutic implications of PAPP-A dysregulation in PABC, emphasizing the need for further research to elucidate underlying mechanisms and develop targeted therapies. Collaborative efforts among researchers, clinicians, and industry stakeholders are essential for translating findings into clinically relevant interventions to improve outcomes for PABC patients.

Primary osteoarthritis chondrocyte map of chromatin conformation reveals novel candidate effector genes

ObjectivesOsteoarthritis is a complex disease with a huge public health burden. Genome-wide association studies (GWAS) have identified hundreds of osteoarthritis-associated sequence variants, but the effector genes underpinning these signals remain...

Unraveling the Predictive Power: Placenta Growth Factor and Pregnancy-Associated Plasma Protein A in Pre-eclampsia.

This review provides a comprehensive exploration of the roles of placenta growth factor (PlGF) and pregnancy-associated plasma protein A (PAPP-A) in the context of pre-eclampsia, a pregnancy-related hypertensive disorder with significant implications for maternal and fetal health. The background elucidates the clinical significance of pre-eclampsia, highlighting its prevalence and impact. The review delves into the biological importance of PlGF and PAPP-A, emphasizing their critical roles in normal placental development and their dysregulation in pre-eclampsia. Notably, altered levels of these biomarkers emerge as potential diagnostic indicators, offering insights into the pathophysiology of the disorder. The exploration of pathophysiological mechanisms, including angiogenic imbalance and placental dysfunction, provides a nuanced understanding of pre-eclampsia's molecular landscape. The therapeutic implications of targeting PlGF and PAPP-A open avenues for future research, aiming at effective intervention strategies. The conclusion summarizes key findings, outlines implications for future research, and underscores the crucial role of PlGF and PAPP-A in understanding and managing pre-eclampsia, with the ultimate goal of improving outcomes for both mothers and infants.

The impact of fresh versus frozen-thawed embryos on maternal serum analyte levels in IVF singleton and twin pregnancies.

To determine whether embryo cryopreservation is associated with a difference in maternal serum analyte levels in singleton and twin pregnancies conceived via in vitro fertilization (IVF). This was a retrospective cohort study of singleton and twin pregnancies conceived via IVF from a university health system from 01/2014 to 09/2019. Patients with available first and second trimester serum analyte data were included and analyzed separately. Multiple of the median (MoM) values for free β-human chorionic gonadotropin (β-hCG), pregnancy-associated plasma protein A, alpha-fetoprotein (AFP), Inhibin A, and unconjugated estriol (uE3) were compared between two groups: pregnancies conceived after the transfer of fresh embryos versus pregnancies conceived after the transfer of frozen-thawed embryos. Multiple linear regression of log MoM values with F test was performed to adjust for potential confounders. For singletons, fresh embryos were associated with a lower median first trimester free β-hCG (1.00 MoM vs. 1.14 MoM; parameter estimate [PE] 0.90, 95% CI 0.82-0.99, p = .03) compared to frozen-thawed embryos. Fresh embryos were also associated with a lower median second trimester uE3 (0.93 MoM vs. 1.05 MoM; PE 0.88, CI 0.83-0.95, p = .0004) and AFP (1.02 MoM vs. 1.19 MoM; PE 0.91, CI 0.84-0.99, p = .02) compared to frozen-thawed embryos in singletons. There were no significant differences between median first and second trimester serum analytes in twin pregnancies compared between the two groups. Singleton pregnancies derived from fresh embryos had lower first (free β-hCG) and second (uE3 and AFP) trimester analytes compared to frozen-thawed embryos. Twin pregnancies demonstrated no difference between the groups.

Assessment of endothelial function in pregnant women with normal pregnancy and pregnancy complicated by hypertensive disorders

Objective. To assess the vascular endothelial function in the first trimester of pregnancy using the method of skin thermometry in the aspect of the development of hypertensive complications.&#x0D; Materials and methods. One hundred women in the first trimester of pregnancy were examined. Based on the gestation outcomes they were divided into two groups: group 1 consisted of 80 patients without pregnancy complications, group 2 included 20 women whose pregnancy was complicated by hypertensive disorders. Clinical and anamnestic risk factors were evaluated; blood pressure level, uterine artery pulsation index, pregnancy-associated plasma protein A were measured; endothelial function was assessed using high-resolution skin thermometry.&#x0D; Results. Analysis of the obtained data showed significant differences in the body mass index, systolic and diastolic blood pressure levels and values of pulsation index in the uterine arteries. An increase in the indicators during the first trimester of pregnancy was observed in patients from the group with hypertensive disorders. The results of measurements of blood flow fluctuations in the microcirculatory system showed no significant differences in the compared groups.&#x0D; Conclusions. The obtained results of measuring the amplitudes of blood flow fluctuations in the microcirculatory system indicate the absence of initial endothelial dysfunction in the maternal body. However, an increase in the body weight, initial level of systolic and diastolic blood pressure, uterine artery pulsation index have an important role in predicting the development of hypertensive disorders in pregnancy.

Early Prediction of Hypertensive Diseases of Pregnancy by Using Combined Screening Methods in a Rural Population.

The most frequent medical issue during pregnancy is hypertension, which can complicate up to 10% to 15% of pregnancies worldwide. An estimated 14% of all maternal fatalities worldwide are thought to be caused by hypertensive disease of pregnancy, one of the main causes of maternal and fetal morbidity and mortality. Despite the fact that maternal mortality is substantially lower in high-income countries than in low- and middle-income countries, hypertension is still one of the leading causes of maternal death globally. Maternal mortality associated with hypertension fluctuated between 0.08 and 0.42 per 100,000 births between 2009 and 2015. In India, the estimated overall pooled prevalence of HDP was determined to be one out of 11 women, or 11% (95% CI, 5%-17%). Despite various government programs, there is still a high prevalence of hypertension, which calls for stakeholders and healthcare professionals to focus on providing both therapeutic and preventive care. The best solution is to concentrate more on the early detection of pregnancy-related hypertension and to guarantee its universal application so that proper care can be carried out to prevent maternal and fetal morbidity. To estimate the predictive value of the combination of maternal characteristics, i.e., mean arterial pressure (MAP), biophysical evaluation (uterine artery Doppler), and biochemical markers (pregnancy-associated plasma protein A (PAPP-A)), in the first trimester of pregnancy for hypertensive diseases of pregnancy. It was a prospective observational study of longitudinal variety thattook over 18 months in a tertiary care rural hospital. The number of women admitted to the hospital for labor care during 2019 was 5261. A total of 513 were diagnosed with hypertensive illnesses during pregnancy. At a prevalence rate of 10%, we calculated a sample size of 350 to achieve a sensitivity of 85% with an absolute error of 12.5% at a 95% CI. Maternal histories, such as age, education, socio-economic status, gravidity, and BMI, were taken along with three parameters, i.e., MAP, which was significant above 90 mmHg, uterine artery Doppler, which was taken significant above 1.69, and serum PAPP-A, which was significant at less than 0.69 ml/IU. We have found that the following are associated with theprediction of hypertension: among the maternal characteristics are advanced age >35 years, presence of body edema, and urine proteins along with MAP, uterine artery pulsatility index (UtA-PI), and PAPP-A are significant. The predictive accuracy of the combination of MAP, UtA-PI, and PAPP-A is also significant. We also found that there is a significant increase in cesarean sections and NICU admissions in hypertensive patients. A combination of screening parameters, including MAP, UtA-PI, and PAPP-A, to predict early hypertensive disease of pregnancy is developed and tested.

Correlation between PAPP-A serum levels in the first trimester of pregnancy with the occurrence of gestational diabetes, a multicenter cohort study

ObjectiveThis study aimed to investigate the association between first-trimester Pregnancy-associated plasma protein A (PAPP-A) levels and subsequent gestational diabetes mellitus (GDM) development.MethodThe study was conducted on 5854 pregnant women who attended routine prenatal care. Maternal biomarkers, including PAPP-A and free beta hCG, were measured for all women in a referral laboratory and converted to MoM values. Pregnant women were divided into two groups, based on the serum concentration of PAPP-A, (PAPP-A > 0.4 (normal) and PAPP-A < 0.4 (low)). Data on the screening test for GDM and pregnancy outcomes were collected and analyzed with appropriate tests.ResultOf the 5854 pregnant women, 889 (15.19%) developed GDM. The maternal PAPP-A MoM concentrations were significantly lower in GDM cases compared to controls. Indeed, gestational age at delivery and birth weight were significantly lower (p < 0.001) in PAPP-A MoM < 0.4, and the rate of intrauterine growth restriction (IUGR) was significantly higher (p < 0.001). ROC analysis revealed that the sensitivity and specificity of MoM concentration for predicting GDM were 53.3% and 51.9%, respectively.ConclusionLower maternal PAPP-A in early pregnancy can lead to glucose intolerance and increase the risk of subsequent GDM development. In addition, decreased serum concentration of PAPP-A is significantly correlated to lower birth weight and IUGR.

Aspirin for evidence-based preeclampsia prevention trial: effects of aspirin on maternal serum pregnancy-associated plasma protein A and placental growth factor trajectories in pregnancy

BackgroundThe exact mechanism by which aspirin prevents pre-eclampsia (PE) remains unclear. Its effects on serum placental biomarkers throughout pregnancy are also unknown. ObjectiveTo investigate the effects of aspirin on serum pregnancy-associated plasma protein A (PAPP-A) and placental growth factor (PlGF) trajectories using repeated measures from women at increased risk of preterm PE. Study DesignThis was a longitudinal secondary analysis of the Combined Multimarker Screening and Randomized Patient Treatment with Aspirin for Evidence-based Preeclampsia Prevention (ASPRE) trial using repeated measures of PAPP-A and PlGF. In the trial, 1,620 women at increased risk of preterm PE were identified using the Fetal Medicine Foundation algorithm at 11-13+6 weeks, of whom 798 were randomly assigned to receive aspirin 150 mg and 822 to receive placebo daily from before 14 weeks to 36 weeks of gestation. Serum biomarkers were measured at baseline and follow-up visits at 19 to 24, 32 to 34, and 36 weeks of gestation. Generalized additive mixed models with treatment by gestational age interaction terms were used to investigate the effect of aspirin on biomarker trajectories over time. ResultsOverall, there were 5,507 PAPP-A and 5,523 PlGF measurements. Raw PAPP-A values increased over time, and raw PlGF increased until 32 weeks of gestation followed by a decline. The multiple of the median (MoM) mean values of the same biomarkers were consistently below 1.0 MoM, reflecting the high-risk profile of the study population. Trajectories of mean PAPP-A and PlGF MoM values did not differ significantly between the aspirin and placebo groups (aspirin treatment by gestational age interaction p-values: 0.259 and 0.335, respectively). ConclusionsIn women at increased risk of preterm PE, aspirin 150 mg daily had no significant effects on PAPP-A or PlGF trajectories when compared to placebo.

Meta-analysis for the relationship between circulating pregnancy-associated plasma protein A and placenta accreta spectrum.

Changes in circulating pregnancy-associated plasma protein A (PAPP-A) have been observed in women with a placenta accreta spectrum (PAS). However, no consensus has been reached according to the previous studies. Our study investigated the relationship between circulating PAPP-A and PAS risk through a systematic review and meta-analysis. Studies comparing the circulating level of PAPP-A between pregnant women with and without PAS were obtained by searching the Medline, Cochrane Library, Embase, CNKI, and Wanfang databases from the inception of the databases until February 12, 2023. Heterogeneity was considered in the pooling of results via a random-effects model. Eight observational studies were obtained for the meta-analysis, which included 243 pregnant women with PAS and 1599 pregnant women without PAS. For all these women, the first-trimester circulating level of PAPP-A was measured by immunoassay and reported as multiples of the median (MoM) values. The pooled results showed that compared to those who did not develop PAS, women with PAS had significantly higher first-trimester serum level PAPP-A (mean difference: 0.43 MoM, 95% confidence interval [CI]: 0.30 to 0.56, P < .001; I2 = 32%). Furthermore, a high first-trimester serum PAPP-A level was related to a high PAS risk (odds ratio: 2.89, 95% CI: 2.13 to 3.92, P < .001; I2 = 0%). Sensitivity analysis which excluded one study at a time, also obtained similar results (p all < 0.05). Pregnant women with a high serum PAPP-A level in the first trimester may be at an increased risk for PAS.

The effect of a vanishing twin on first- and second-trimester maternal serum markers and ultrasound screening for aneuploidy.

A vanishing twin (VT) is the early demise of a twin fetus. It is estimated to occur in 20-30% of pregnancies associated with assisted reproductive technology. VT becomes increasingly prominent when assisted fertilization is used, because one or more embryos are transferred to the uterus. Maternal serum screening tests during pregnancy can screen for trisomy chromosomes 21, 18, and 13 and are divided into first- and second-trimester tests. In singleton pregnancies, the first trimester screening test is performed at 11-13 weeks and 6 days of gestation. It consists of two serum markers, pregnancy-associated plasma protein A and β-human chorionic gonadotropin (β-hCG), and measures nuchal translucency thickness. The second-trimester screening test was performed at 15-20 weeks and 6 days of gestation. It consists of four serum markers: alpha-fetoprotein, β-hCG, unconjugated estriol, and inhibin A. More effective screening for trisomy 21 in singleton pregnancies is achieved by analyzing cell-free DNA in the maternal blood. A VT includes a demise of the fetus. Although it affects maternal serum markers, it has not been corrected. Five studies examined the effect of VT on maternal serum markers, but the results were controversial. This study aimed to review the patterns of changes in maternal serum markers in VTs, interpret prenatal tests for pregnant women with VTs in clinical practice, and consider what information should be provided.

A new contingent screening strategy increased detection rate of trisomy 21 in the first trimester

BackgroundAlthough the traditional contingent screening strategy is effective, there are still undetected low-risk trisomy 21. This study aims to define appropriate cut-off values of serum biochemical markers at low-risk and develop a strategy for sequential prenatal testing associated with first-trimester screening to increase the detection rate of trisomy 21.MethodsThis was a 9-year retrospective analysis of singleton pregnant women who underwent serum biochemical screening or combined first-trimester screening (CFTS) in the first trimester. For the low-risk group, the cut-off values of the serum biochemical markers were adjusted to determine the appropriate detection efficiency. Gravidas with abnormal serum biochemical markers at low-risk were advised to undergo further non-invasive prenatal screening (NIPS), whereas others continued with routine prenatal care.ResultsWhen cut-off values of free beta subunit of human chorionic gonadotropin (free β-hCG) multiples of the median (MoM) or pregnancy-associated plasma protein A (PAPP-A) MoM were defined with ≥ 2.75 or ≤ 0.5, 7.72% (2,194/28,405) in the serum biochemical screening group and 12.36% (4,005/32,403) in CFTS group could be detected as abnormal results for further NIPS. Finally, 55.56% (5/9) and 85.71% (6/7) of trisomy 21 cases with false-negative results were detected, and the overall detection rate for trisomy 21 was improved by 10.64% (5/47) and 12.77% (6/47), respectively.ConclusionsThe new contingent screening strategy can increase the detection rate of trisomy 21 compared with the traditional contingent screening strategy.

The value of combined detailed first-trimester ultrasound-biochemical analysis for screening fetal aneuploidy in the era of non-invasive prenatal testing.

This study aimed to investigate the performance, cost-effectiveness and additional findings of combined detailed ultrasound and biochemical screening for risks of major fetal trisomies in the first-trimester. This is a retrospective analysis study, we estimated the risk of trisomies 21, 18 and 13 based on maternal age, fetal nuchal translucency thickness, nasal bone, ductus venosus pulsatility index velocity, tricuspid regurgitation, fetal heart rate, free beta-human chorionic gonadotropin, and pregnancy-associated plasma protein A in singleton pregnant women, and performed non-invasive prenatal testing for women with risks of trisomy 21 between 1:500 and 1:300. Invasive diagnostic testing was performed for women with positive or failed non-invasive prenatal testing result and in the high-risk group of this screening method. The direct costs were compared between this strategy and the non-invasive prenatal testing which alone used as first-line screening for all pregnant women. Among 25,155 singleton pregnant women who underwent screening, 24,361 were available for analysis, of these, 194 cases underwent non-invasive prenatal testing. Among the 24,361 women, 39, 19, and 7 had trisomies 21, 18 and 13, respectively. The use of this strategy could potentially detect approximately 94.87% of trisomy 21 cases, 100% of trisomy 18 cases, and 100% of trisomy 13 cases, with false-positive rates of 2.49%, 0.41%, and 0.49%, respectively. The overall detection rate and overall false-positive rates were 96.92% and 2.52%, respectively. The detection rate was 100% in the advanced age group and 94.12% in the general age group. Additionally, structural abnormalities were detected in 137 fetuses, and 44 fetuses had other chromosomal abnormalities. The total cost of this strategy was $3,730,843.30, and the cost per person tested was $153.15. The total cost of using non-invasive prenatal testing as the first-line strategy would be $6,813,387.04 and the cost per person tested was $279.68. Our strategy is an efficient and cost-effective approach for detecting major trisomies and identifying more fetuses with a potential abnormality. Therefore, this strategy is a valuable screening method and highly feasible in the clinical setting.

Impact of Endometrial Preparation on the Maternal and Fetal Cardiovascular Variables of the First Trimester Combined Screening Test

The modality of endometrial preparation for the transfer of frozen-thawed embryos may influence maternal and fetal adaptation to pregnancy and could thus impact the results of the first trimester combined screening test. We conducted a retrospective cross-sectional study on singleton pregnancies achieved by embryo transfer of a single frozen-thawed blastocyst, comparing two different endometrial preparation protocols: natural cycle (n = 174) and hormone replacement therapy (HRT) (n = 122). The primary outcome was the risk of preeclampsia at the first trimester combined screening test. Secondary endpoints included variable reflecting fetal cardiac function (nuchal translucency and fetal heart rate), maternal adaptation (median arterial blood pressure—MAP and uterine arteries pulsatility index—UtA-PI), and placentation (pregnancy associated plasma protein A and placental growth factor). The risk of early preeclampsia was comparable in the two groups (38% vs. a 28%, p = 0.12). However, women in the natural cycle group showed lower fetal heart rate (159 [155–164] vs. 164 [158–168], p = 0.002) and higher UtA-PI (0.96 [0.74–1.18] vs. 0.72 [0.58–0.90], p &lt; 0.001). The frequency of a screening test at high risk for aneuploidies was similar. The modality of transfer of frozen-thawed embryos is associated with changes in the variables reflecting maternal and fetal cardiovascular function.

Cryo-EM structure of human PAPP-A2 and mechanism of substrate recognition

Pregnancy-Associated Plasma Protein A isoforms, PAPP-A and PAPP-A2, are metalloproteases that cleave insulin-like growth factor binding proteins (IGFBPs) to modulate insulin-like growth factor signaling. The structures of homodimeric PAPP-A in complex with IGFBP5 anchor peptide, and inhibitor proteins STC2 and proMBP have been recently reported. Here, we present the single-particle cryo-EM structure of the monomeric, N-terminal LG, MP, and the M1 domains (with the exception of LNR1/2) of human PAPP-A2 to 3.13 Å resolution. Our structure together with functional studies provides insight into a previously reported patient mutation that inactivates PAPP-A2 in a distal region of the protein. Using a combinational approach, we suggest that PAPP-A2 recognizes IGFBP5 in a similar manner as PAPP-A and show that PAPP-A2 cleaves IGFBP5 less efficiently due to differences in the M2 domain. Overall, our studies characterize the cleavage mechanism of IGFBP5 by PAPP-A2 and shed light onto key differences with its paralog PAPP-A.