Table 4. The adjusted ORs for the risk of breast cancer (diagnosed within maximum 4 years after childbirth) in the Group 2 population with a total 457,924 deliveries in 2010.
| ORa (95% CI) | |
|---|---|
| Old age (≥35 years) | 2.777 (2.356–3.274) |
| Primipara | 0.673 (0.571–0.794) |
| Pre-eclampsia | 1.050 (0.663–1.663) |
| Gestational diabetes | 1.368 (0.907–2.063) |
| Twin pregnancy | 0.876 (0.451–1.700) |
| Cesarean delivery | 1.211 (1.034–1.418) |
aMultivariate logistic regression analysis was performed. ORs were adjusted for all variables in the table.
OR, odds ratio; CI, confidence interval.