MA, maternal age; GA, gestational age; MAD, median absolute deviation; na, not available.
| Cohort 1 (n = 72,932) | Cohort 2 (n = 16,885) | Cohort 1 versus cohort 2 | ||||||
| Variable | No flag | Flagged | P | No flag | Flagged | P | P (no flag) | P (flagged) |
| Samples, n (% total) | 72,414 (99.29%) | 518 (0.71%) | na | 16,776 (99.35%) | 109 (0.65%) | na | 0.383 (difference in proportions of flagged versus nonflagged, comparing cohort 1 to cohort 2) | |
| MA (years) | ||||||||
| Median ± MAD | 35.6 ± 4.4 | 36.1 ± 5.1 | 0.003 | 34.4 ± 4.4 | 35.7 ± 5.5 | 0.01 | <0.0005 | 0.945 |
| Mean ± SD | 34.6 ± 5.4 | 35.1 ± 5.8 | 34.4 ± 4.3 | 35.6 ± 4.9 | ||||
| Min–Max | 13.8–66.6 | 14.0–50.7 | 18.2–62.2 | 19.8–46.4 | ||||
| GA (weeks) | ||||||||
| Median ± MAD | 12.0 ± 3.0 | 12.0 ± 3.0 | 0.83 | 10.0 ± 0 | 10.0 ± 0 | 0.847 | <0.0005 | <0.0005 |
| Mean ± SD | 13.8 ± 4.2 | 13.9 ± 4.4 | 11.0 ± 1.9 | 11.2 ± 2.6 | ||||
| Min–Max | 10–40 | 10–35 | 10–36 | 10–31 | ||||
| Trimester (% of samples) | ||||||||
| First (10–13.9 weeks) | 47,498 (65.60%) | 331 (63.80%) | 0.402 | 15,560 (92.80%) | 97 (89.00%) | 0.025 | <0.0005 | <0.0005 |
| Second (14–27.9 weeks) | 23,956 (33.10%) | 177 (34.20%) | 1,207 (7.20%) | 11 (10.10%) | ||||
| Third (28–40+ weeks) | 960 (1.30%) | 10 (1.90%) | 9 (0.10%) | 1 (0.90%) | ||||