Table 3.
Likelihood of Fetal Heartbeats >1 versus 1 by Embryos Transferred and Maternal Age Categories*
| All | <35 years | 35–40 years | |||||
|---|---|---|---|---|---|---|---|
| N, pregnancies | 6,073 | 2,392 | 2,764 | ||||
| Variable | Categories | AOR | 95% CI | AOR | 95% CI | AOR | 95% CI |
| Oocyte Source | Autologous | 1.00 | Reference | ||||
| Donor | 1.49 | 1.10, 2.01 | |||||
| Assisted Hatching | No | 1.00 | Reference | 1.00 | Reference | ||
| Yes | 1.31 | 1.07, 1.59 | 1.49 | 1.03, 2.15 | |||
| Embryos Transferred | 1–2 | 1.00 | Reference | 1.00 | Reference | 1.00 | Reference |
| ≥3 | 2.04 | 1.68, 2.48 | 1.66 | 1.08, 2.55 | 2.39 | 1.84, 3.11 | |
*
Models adjusted for all factors in the table