Characteristics | n (%) unless otherwise stated |
---|---|
Low risk NIPT results | 35,955 (98.6) |
Singleton pregnancies (%) | 35,650 (97.8) |
Twin pregnancies (%) | 800 (2.2) |
Triplet pregnancies,(%) | 6 (0.02) |
ART Pregnancies(%) | 1807 (5) |
Twin pregnancies (%) | 403 (22.3) |
Egg donation (%) | 16 (0.9) |
Maternal age (yrs) mean (range)* | 35.4 (18–48) |
< 35(%) | 19,693 (54) |
≥ 35(%) | 16,763 (46) |
Gestational age (wks + days) mean (range) | 12 + 2 (9 + 1–32 + 6) |
Samples drawn in first trimester (< 13 + 6 wks) | 27,780 (76.2%) |
Fetal fraction mean ± SD | 9.55 ± 3.72 |
Fetal fraction first trimester mean ± SD | 9.53 ± 3.69 |