Table 1.
Overview of Sample Characteristics for Both Studies
| Parameter | Study 1 | Study 2 |
|---|---|---|
| Number of samples | 42 | 53 |
| Average sample volume | 28.5 mL, ± 3.1 mL | 36.2 mL, ± 4.3 mL |
| Gestational age | 8 weeks, 2 days to 20 weeks, 6 days (average: 13 weeks, 2 days, ± 2 weeks, 5 days) | 9 weeks, 3 days to 29 weeks, 5 days (average: 13 weeks, 6 days, ± 3 weeks, 5 days) |
| Plurality and Fetal sex | 22 F singletons/18 M singletons/2 twins (1 F+M and 1 M+M) | 20 F singletons/27 M singletons/6 twins (4 F+M, 1 M+M, and 1 F+F) |
| Recruitment site | 29 Houston; 13 New York | 39 Houston; 14 New York |
| Maternal age | 26–43 years old (average: 34.7 years old, ± 3.9 years) | 19–41 years old (average: 33.1 years old, ± 5.2 years) |
| Maternal BMI | 19.0–42.7 kg/m2 (average: 26.3 kg/m2, ± 5.4 kg/m2) | 18.9–41.3 kg/m2 (average: 27.3 kg/m2, ± 6.0 kg/m2) |
| Clinical diagnostic testing | 19 procedures: 13 CVS (of which 6 blood samples were collected post-CVS); 5 amniocentesis (none were collected post-amnio); 1 both (sample was collected after amniocentesis procedure) // 23 no procedure | 25 procedures: 14 CVS (of which 9 samples were collected post-CVS); 10 amniocentesis (of which 3 samples were collected post-amnio); 1 both (sample was collected after CVS procedure) // 28 no procedure |
| Main Indication for Genetic Counseling and/or Diagnostic Testing | ||
| AMA | 23 (54.8%) | 20 (37.7%) |
| Abnormal cell-free NIPT | 3 (7.1%) | 3 (5.7%) |
| Abnormal ultrasound | 3 (7.1%) | 9 (17.0%) |
| Parental indication (balanced translocation, carrier) | 3 (7.1%) | 3 (5.7%) |
| Regular first trimester screen (not AMA) | 3 (7.1%) | 7 (13.2%) |
| Abnormal prior pregnancy | 1 (2.4%) | 3 (5.7%) |
| Abnormal quad screen | 1 (2.4%) | - |
| Abnormal CVS | 1 (2.4%) | - |
| Abnormal serum screen | - | 1 (1.9%) |
| Abnormal PGT result | - | 1 (1.9%) |
| Combination of 2 or 3 of the above | 4 (9.5%) | 6 (11.3%) |
| Trophoblast Yield as Identified by Microscopy | ||
| Total | 226 cells | 398 cells |
| Per sample: average | 5.38 cells/sample | 7.51 cells/sample |
| Per sample: median | 3.00 cells/sample | 6.00 cells/sample |
| Per sample: range | 1–23 cells/sample | 0–26 cells/sample |
| Per mL maternal blood: average | 0.19 cells/mL | 0.21 cells/mL |
| Per mL maternal blood: median | 0.11 cells/mL | 0.18 cells/mL |
| Number of samples with cell clusters | 18 (43%) | 28 (53%) |
∗AMA, advanced maternal age; BMI, body mass index; CVS, chorionic villi sampling; F, female; M, male; NIPT, noninvasive prenatal testing; PGT, preimplantation genetic testing; SD, standard deviation