Table 1:
Variable importance for pre-viability & all-pregnancy models
| Category | Measure | Pre-viability | All-pregnancy | Pre-viability without 2nd trimester screening |
|---|---|---|---|---|
| Demographics (maternal) | Age (years) | 3.93 | 26.0 | 7.62 |
| Education (years) | 10.9 | 18.7 | 26.4 | |
| Ethnicity (Hispanic) | 1.54 | 14.9 | 3.91 | |
| Race (minority) | 100.0 | 40.7 | 100.0 | |
| Born in United States | 2.99 | 3.83 | 2.07 | |
| Interview conducted in English | 0.00 | 1.96 | 0.23 | |
| Demographics (biologic father of baby) | Ethnicity (Hispanic) | 13.8 | 13.8 | 12.6 |
| Race (minority) | 56.5 | 11.1 | 80.2 | |
| Education (years) | 14.4 | 18.7 | 10.1 | |
| Born in United States | 0.41 | 6.41 | 0.57 | |
| Family history | Chromosomal anomaly | 0.31 | 0.82 | 0.59 |
| Congenital disorder | 0.25 | 1.48 | 0.00 | |
| Developmental delay | 0.77 | 0.75 | 1.21 | |
| Congenital heart disease | 2.39 | 1.50 | 4.18 | |
| Neonatal death | 2.29 | 4.77 | 5.00 | |
| Blood disorder | 0.20 | 1.77 | 0.98 | |
| Neuromuscular disorder | 0.00 | 10.4 | 0.00 | |
| Intrauterine fetal demise | 5.52 | 10.8 | 5.11 | |
| Recurrent pregnancy loss | 1.37 | 1.73 | 2.78 | |
| Diabetes | 0.32 | 2.98 | 0.00 | |
| Maternal health history | Any chronic condition | 0.00 | 13.3 | 4.19 |
| Asthma | 0.55 | 1.87 | 0.24 | |
| Blood disorder | 0.00 | 14.2 | 0.00 | |
| Cardiovascular disease | 0.82 | 12.6 | 1.46 | |
| Gastrointestinal disorder | 0.29 | 6.87 | 0.00 | |
| Hypertension (pre-pregnancy) | 0.80 | 1.83 | 1.58 | |
| Diabetes (pre-pregnancy) | 1.30 | 1.30 | 2.13 | |
| Obesity (body mass index ≥30) | 1.46 | 4.98 | 5.41 | |
| Rheumatologic disease | 0.00 | 11.5 | 0.00 | |
| Kidney disease | 0.59 | 15.5 | 0.54 | |
| Thyroid disease | 0.00 | 0.58 | 0.00 | |
| Mental health condition | 0.00 | 7.59 | 0.00 | |
| Depression | 0.44 | 8.64 | 0.28 | |
| Sexually transmitted infection | 0.46 | 1.62 | 0.22 | |
| Surgery | 0.36 | 8.73 | 2.81 | |
| Urinary tract infection | 0.25 | 3.36 | 7.21 | |
| Obstetric history | Intrauterine fetal demise | 28.8 | 10.9 | 54.3 |
| Fertility treatment | 1.37 | 2.25 | 0.00 | |
| Spontaneous abortion | 3.60 | 3.50 | 3.05 | |
| Total pregnancies (number) | 8.45 | 11.1 | 16.9 | |
| Social history | Received income assistance | 17.5 | 10.5 | 17.0 |
| Significant life events 12 months prior to delivery | 13.5 | 9.83 | 14.9 | |
| Marital status (married) | 3.19 | 16.9 | 1.92 | |
| Moved during pregnancy | 9.64 | 4.84 | 8.08 | |
| Biologic father of baby involved in pregnancy care | 0.00 | 5.23 | 0.00 | |
| Partner desired pregnancy | 2.24 | 10.5 | 2.05 | |
| Patient desired pregnancy | 1.97 | 19.0 | 1.23 | |
| Unstable living situation | 2.44 | 1.13 | 3.02 | |
| Substance use | Smoking during pregnancy | 0.80 | 2.30 | 0.97 |
| Alcohol during pregnancy | 5.03 | 17.2 | 2.75 | |
| Other drug use during pregnancy | 0.00 | 0.43 | 0.00 | |
| Prenatal laboratory data | Anemia screen (positive) | 16.6 | 8.54 | 36.6 |
| Rubella screen (positive) | 0.21 | 0.61 | 0.00 | |
| Chlamydia (positive) | 0.22 | 0.63 | 1.36 | |
| Diabetic screen (positive) | Not in model | 0.98 | Not in model | |
| Anti-D antibodies | 0.00 | 0.90 | 2.20 | |
| Urine culture (positive) | Not in model | 2.52 | Not in model | |
| Bleeding disorder (labor/delivery) | Not in model | 11.0 | Not in model | |
| Anemia (labor/delivery) | Not in model | 20.9 | Not in model | |
| Leukocytosis (labor/delivery) | Not in model | 7.48 | Not in model | |
| Thrombocytopenia (labor/delivery) | Not in model | 1.34 | Not in model | |
| Proteinuria | Not in model | 8.77 | Not in model | |
| 2nd trimester (quad) screen | Down syndrome risk | 3.62 | 23.6 | Not in model |
| hCG (MoM) | 23.1 | 44.3 | Not in model | |
| MSAFP (MoM) | 12.6 | 27.2 | Not in model | |
| UE3 (MoM) | 1.66 | 28.6 | Not in model | |
| Prenatal care | Fluid loss | Not in model | 1.76 | Not in model |
| Abdominal pain (prior to onset of labor) | Not in model | 23.4 | Not in model | |
| Vaginal bleeding | Not in model | 5.15 | Not in model | |
| Hospitalization (prior to delivery) | Not in model | 25.5 | Not in model | |
| Preterm labor (prior to delivery) | Not in model | 3.42 | Not in model | |
| Reduced fetal movement | Not in model | 13.4 | Not in model | |
| Elevated blood pressure | Not in model | 8.05 | Not in model | |
| Influenza during pregnancy | Not in model | 9.30 | Not in model | |
| Earliest prenatal visit (GA) | 67.7 | 57.0 | 64.8 | |
| Ratio of latest prenatal visit to bGA | Not in model | 92.9 | Not in model | |
| Ratio of total prenatal visits to bGA | Not in model | 26.0 | Not in model | |
| GA at which pregnancy discovered | 11.7 | 27.2 | 24.5 | |
| Ultrasound | Fetal anomaly | 6.88 | 1.53 | 12.0 |
| Sex (female) | 5.64 | 29.9 | 9.85 | |
| 10-week ultrasound (completed) | 2.80 | 9.70 | 0.75 | |
| Anatomy ultrasound (completed) | 0.00 | 17.6 | 9.95 | |
| Abnormal fluid (oligohydramnios or polyhydramnios) | Not in model | 16.1 | Not in model | |
| Abnormal growth (large [>90th percentile] or small [<10th percentile] for gestational age) | Not in model | 1.13 | Not in model | |
| Placental anomalies | Not in model | 1.23 | Not in model | |
| Earliest ultrasound (GA) | 46.0 | 60.7 | 66.4 | |
| Ratio of latest ultrasound to bGA | Not in model | 100.0 | Not in model |
Values are given as variable importance (range 0–100). Values >10 (higher importance to model accuracy) indicated in bold.
Non-contributory to model (importance <1.0): Family history of cystic fibrosis, neural tube defect; maternal health history of cancer, seizures; history of emotional, physical, or sexual abuse; positive gonorrhea, syphilis, or antibody screen
Abbreviations: hCG = human chorionic gonadotropin; MoM = multiples of median; MSAFP = maternal serum alpha-feto protein; UE3 = unconjugated estriol; GA = gestational age; bGA = gestational age at birth/delivery