How This Workbench Is Built
Every risk number is built from primary, peer-reviewed literature and validated against each source paper's own published values. Nothing is a black box.
The scientific method:
prior risk → gestation-adjusted markers → published likelihood or competing-risk model → calibrated probability → clinical pathway
Analytically VerifiedReproduces the source paper's equations, tables or worked examples within a defined tolerance.
Literature-DerivedCoefficients / likelihood ratios extracted from identified published sources.
Partially ValidatedStructure is literature-derived; a parameter or calibration constant still needs confirmation.
Pathway EngineA guideline-derived clinical pathway, not a numerical prediction model.
Aneuploidy (T21 / T18 / T13)
Analytically Verified▶Background prior (age + GA)
Source: Snijders 1995/1999; Hartwig 2016
Validation: Snijders tables reproduced within rounding
▶NT likelihood ratio
Source: Wright 2008 (mixture model); Vale 2021 (MoM)
Validation: Spencer 2003 table 4; Kagan 2008 table III
▶Nasal bone
Source: Kagan 2009 (logistic model, CRL/NT/smoker/PAPP-A/β-hCG/ethnicity)
Validation: Kagan 2009 table II
▶Ductus venosus
Source: Maiz 2012 (log10 MoM PIV, ethnicity)
Validation: Maiz 2012 table IV
▶Tricuspid regurgitation
Source: Kagan 2009 (unconditional LR, present/absent)
Validation: Kagan 2009 table II
▶Fetal heart rate
Source: Kagan 2008 (Gaussian delta-FHR, GA-dependent T13)
Validation: Kagan 2008 table IV
▶Biochemistry (PAPP-A, free β-hCG, PlGF)
Source: Kagan 2008 (bivariate Gaussian, log10 MoM); Tørring 2016 (Roche)
Validation: Kagan 2008 table II; Tørring 2016 ROC points
▶AFP (T21 add-on)
Source: Bredaki 2011
Validation: Bredaki 2011 table 2
▶cfDNA / NIPT contingent pathway
Source: Bardi 2023; Becking 2023; Gil 2017 meta-analysis
Validation: Gil 2017 DR/FPR points
Placental Health (PE / FGR / Stillbirth)
Analytically Verified▶Pre-eclampsia competing risks
Source: Wright 2020 (maternal factors + MAP, UtA-PI, PlGF, PAPP-A)
Validation: O'Gorman 2016 (DR/FPR points); Tan 2018
▶FGR/SGA competing risks
Source: Papastefanou 2020/2021 (maternal + PAPP-A, PlGF)
Validation: Papastefanou 2020 table 3
▶Stillbirth (PlGF band)
Source: Akolekar 2016 (maternal + PlGF MoM band)
Validation: Akolekar 2016 figure 2
Cardiac (CHD)
Pathway Engine▶NT/DV/TR → fetal echo referral
Source: Minnella 2020; meta-analysis 2025 (PROSPERO CRD42023401007)
Validation: Pooled sens/spec per marker; indicative post-test probability
Spontaneous Preterm Birth
Pathway Engine▶Cervical-length model
Source: Celik 2008 (maternal + CL)
Validation: Celik 2008 tables
▶qfFN rule-out
Source: Narice 2022; lipidomic score
Validation: Celik 2008; Narice 2022 ROC
Gestational Diabetes
Analytically Verified▶Multivariable logistic regression
Source: Syngelaki 2025 BJOG (Table 2)
Validation: Calibration intercept 0.000, slope 1.000, AUROC 0.757
Fetal Loss
Literature-Derived▶Miscarriage & stillbirth risk
Source: Akolekar 2011 (age/GA/ethnicity/history)
Validation: Akolekar 2011 tables II–IV
Twins
Pathway Engine▶Chorionicity-correct aneuploidy
Source: Vandecruys 2005 (MC; geometric mean NT LR); Sebire 1996
Validation: Vandecruys 2005 figure
▶Discordance / surveillance
Source: ISUOG 2025 practice guidelines
Validation: Guideline-derived
LGA / Macrosomia
Literature-Derived▶Large-for-gestational-age
Source: Poon 2011 (maternal factors + PAPP-A, PlGF)
Validation: Poon 2011 AUC 0.76
Major Fetal Anomalies
Literature-Derived▶Anomaly CDS (structural → aneuploidy)
Source: Kagan 2010 (UOG 36:10–14); Syngelaki 2017 (UOG 50:45–48)
Validation: Published aneuploidy rates per anomaly type
© 2026 Aliou (github.com/Alioud16). All rights reserved.
Screening decision-support only. Not a diagnosis. Models are literature-derived and validated against their source papers but are not clinically validated on local data — treat status as "pending local calibration."