Table 3. Birth via Cesarean Delivery and Risk of Early-Onset Colorectal Cancer.
| Group | Vaginal delivery | Cesarean delivery |
|---|---|---|
| All participants | ||
| Cases:controls, No. | 509:2005 | 55:175 |
| Model 1: OR (95% CI)a | 1 [Reference] | 1.25 (0.90-1.73) |
| Model 2: aOR (95% CI)b | 1 [Reference] | 1.28 (0.91-1.79) |
| Model 3: aOR (95% CI)c | 1 [Reference] | 1.32 (0.93-1.86) |
| Females | ||
| Cases:controls, No. | 249:991 | 31:85 |
| Model 1: OR (95% CI)a | 1 [Reference] | 1.50 (0.96-2.33) |
| Model 2: aOR (95% CI)b | 1 [Reference] | 1.62 (1.01-2.60) |
| Model 3: aOR (95% CI)c | 1 [Reference] | 1.64 (1.01-2.69) |
| Males | ||
| Cases:Controls, No. | 260:1014 | 24:90 |
| Model 1: OR (95% CI)a | 1 [Reference] | 1.03 (0.64-1.66) |
| Model 2: aOR (95% CI)b | 1 [Reference] | 1.05 (0.64-1.72) |
| Model 3: aOR (95% CI)c | 1 [Reference] | 1.09 (0.66-1.81) |
Abbreviation: aOR, adjusted odds ratio.
Model 1 was conditioned on matching factors, including age at index date (continuous), sex, calendar year of index date (continuous), and county of residence.
Model 2 was additionally adjusted for maternal and pregnancy-related factors at delivery: maternal history of cesarean delivery (yes, no), maternal age at delivery (≤24, 25-29, 30-34, or ≥35 years), maternal country of birth (Nordic, non-Nordic), living with a partner (yes, no), maternal educational level (elementary, secondary, or college), and parity (1, 2, 3, or ≥4).
Model 3 was additionally adjusted for birth characteristics, including gestational age (<36, 37-39, 40-42, or ≥43 weeks), birth weight (<2500, 2500 to <3000, 3000 to <3500, 3500 to <4000, and ≥4000 g), and birth length (continuous).