Table 1.
Overview of sample characteristics
| Sample | ART | Maternal age | BMI | Singleton/gemelli | Fetal sex | GW at 1st blood draw | fEVTs in GW 6–8 | GW at 2nd blood draw | fEVTs in GW 12–13 | GW at 3rd blood draw | fEVTs in GW 19–20 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| ID1 | IUI-D | 30 | 32 | Singleton | Female | 7 + 1 | 1 | 12 + 1 | 10 | 20 + 1 | 5 |
| ID2 | IUI-H | 28 | 22 | Singleton | Male | 6 + 4 | 8 | 13 + 6 | 5 | 20 + 0 | 4 |
| ID3 | IUI-D | 36 | 20 | Singleton | Female | 8 + 5 | 2 | 12 + 5 | 13 | 20 + 0 | 3 |
| ID4 | OI | 31 | 25 | Singleton | Male | 8 + 4 | 6 | 12 + 6 | 10 | 19 + 4 | 5 |
| ID5 | IUI-H | 37 | 38 | Singleton | Male | 8 + 5 | 4 | 12 + 2 | 8 | 20 + 3 | 3 |
| ID6 | IVF-H | 33 | 22 | Singleton | Male | 7 + 1 | 2 | 12 + 4 | 18 | 19 + 4 | 0 |
| ID7 | OI | 29 | 20 | Singleton | Male | 7 + 0 | 20 | 12 + 3 | 11 | 19 + 2 | 16 |
| ID8 | IUI-D | 35 | 30 | Singleton | Female | 7 + 1 | 7 | 13 + 0 | 5 | 20 + 3 | 5 |
| ID9 | IUI-D | 36 | 22 | Singleton | Female | 7 + 3 | 3 | 12 + 5 | 15 | 20 + 0 | 7 |
| ID10 | Noa | 26 | 24 | Singleton | Female | 7 + 0 | 1 | 13 + 1 | 2 | 20 + 0 | 7 |
| ID11 | IUI-H | 35 | 29 | Gemelli | Male/male | 7 + 3 | 6 | 13 + 2 | 13 | 20 + 1 | 7 |
| ID12 | IUI-H | 31 | 21 | Singleton | Female | 6 + 6 | 7 | 13 + 3 | 29 | 20 + 3 | 4 |
| ID13 | IUI-H | 30 | 21 | Gemelli | Male/female | 7 + 3/7+5b | 4 | 13 + 1 | 15 | 20 + 1 | 3 |
ART assisted reproductive technology, BMI body mass index, IUI-D insemination with donor semen, IUI-H insemination with partner semen, OI ovulation induction, IVF-H in vitro fertilization with partner semen, GW gestational week
aThe woman conceived naturally before treatment was initiated
bThe twins had different crown-rump lengths resulting in different GWs