Table 3.
Clinical outcome in nine twin pregnancies with non‐invasive prenatal testing (NIPT) result of aneuploidy detected or suspected included in Clinical Study B
| Sample | NIPT result | Clinical outcome | ||||
|---|---|---|---|---|---|---|
| Aneuploidy | Chromosome Y | Twin A | Twin B | Source | Details | |
| 1 | T21 detected | Present | XY + 21 | XY | CVS | |
| 2 | T21 detected | Present | XY + 21 | XY | CVS | |
| 3 | T21 detected | Present | XY + 21 | XX | Amniocentesis | Triplet to dizygotic twins |
| 4 | T21 detected | Present | XY + 21 | XX | Amniocentesis | |
| 5 | T21 detected | Present | XX + 21 | XY | Visual exam at birth | |
| 6 | T21 detected | NA* | XY + 21 | XX | Cord blood analysis | |
| 7 | T21 suspected | Present | XY | XX | Amniocentesis | 1.27 Mb microduplication of 20q11 in one fetus |
| 8 | T21 detected | Absent | Abnormal findings† | Normal findings | Ultrasound exam | |
| 9 |
T21 detected, T18 suspected |
Present | Demise | NA | ||
Of the six clinical cases with confirmed fetal trisomy, three underwent selective reduction of affected twin, two delivered both twins and the other case began as a triplet pregnancy with demise of one fetus at 6 weeks; amniocentesis of the remaining two viable fetuses confirmed trisomy 21 in one and normal karyotype in the other.
*
Fetal sex information not requested.
†
Included increased nuchal translucency, absent stomach, pyelectasis and polyhydramnios.
CVS, chorionic villus sampling; Mb, megabases; NA, not available; T, trisomy.