Table 4.
Associations between length of pregnancy in women and cause specific mortality with up to 44 years of follow-up
| Deaths | Hazard ratio (95% CI)* | P value | |
|---|---|---|---|
| Cardiovascular | |||
| Preterm (<37 weeks) | 1475 | 1.79 (1.69 to 1.90) | <0.001 |
| Extremely preterm (22-27 weeks) | 62 | 2.09 (1.62 to 2.68) | <0.001 |
| Very preterm (28-33 weeks) | 446 | 2.30 (2.09 to 2.54) | <0.001 |
| Late preterm (34-36 weeks) | 967 | 1.62 (1.51 to 1.73) | <0.001 |
| Early term (37-38 weeks) | 2592 | 1.26 (1.21 to 1.32) | <0.001 |
| Full term (39-41 weeks) | 5941 | Reference | — |
| Post-term (≥42 weeks) | 745 | 1.11 (1.02 to 1.19) | 0.01 |
| Per additional week (trend) | — | 0.91 (0.90 to 0.92) | <0.001 |
| Cancer | |||
| Preterm (<37 weeks) | 3519 | 1.18 (1.14 to 1.23) | <0.001 |
| Extremely preterm (22-27 weeks) | 142 | 1.34 (1.13 to 1.58) | 0.001 |
| Very preterm (28-33 weeks) | 903 | 1.29 (1.21 to 1.38) | <0.001 |
| Late preterm (34-36 weeks) | 2474 | 1.14 (1.10 to 1.19) | <0.001 |
| Early term (37-38 weeks) | 8321 | 1.04 (1.01 to 1.06) | 0.007 |
| Full term (39-41 weeks) | 23 169 | Reference | — |
| Post-term (≥42 weeks) | 2362 | 1.00 (0.96 to 1.05) | 0.83 |
| Per additional week (trend) | — | 0.97 (0.97 to 0.98) | <0.001 |
| Breast cancer | |||
| Preterm (<37 weeks) | 752 | 1.11 (1.03 to 1.20) | 0.009 |
| Extremely preterm (22-27 weeks) | 35 | 1.45 (1.04 to 2.02) | 0.03 |
| Very preterm (28-33 weeks) | 195 | 1.23 (1.06 to 1.42) | 0.005 |
| Late preterm (34-36 weeks) | 522 | 1.05 (0.96 to 1.15) | 0.26 |
| Early term (37-38 weeks) | 1938 | 1.03 (0.98 to 1.09) | 0.26 |
| Full term (39-41 weeks) | 5234 | Reference | — |
| Post-term (≥42 weeks) | 523 | 1.06 (0.97 to 1.16) | 0.19 |
| Per additional week (trend) | — | 0.99 (0.98 to 1.00) | 0.07 |
| Respiratory | |||
| Preterm (<37 weeks) | 416 | 2.15 (1.92 to 2.40) | <0.001 |
| Extremely preterm (22-27 weeks) | 23 | 3.24 (2.14 to 4.90) | <0.001 |
| Very preterm (28-33 weeks) | 96 | 2.11 (1.71 to 2.60) | <0.001 |
| Late preterm (34-36 weeks) | 297 | 2.11 (1.86 to 2.39) | <0.001 |
| Early term (37-38 weeks) | 630 | 1.31 (1.19 to 1.44) | <0.001 |
| Full term (39-41 weeks) | 1478 | Reference | — |
| Post-term (≥42 weeks) | 180 | 0.99 (0.84 to 1.15) | 0.86 |
| Per additional week (trend) | — | 0.90 (0.89 to 0.91) | <0.001 |
| Diabetes | |||
| Preterm (<37 weeks) | 237 | 3.20 (2.69 to 3.82) | <0.001 |
| Extremely preterm (22-27 weeks) | 9 | 4.37 (2.24 to 8.53) | <0.001 |
| Very preterm (28-33 weeks) | 60 | 3.84 (2.90 to 5.07) | <0.001 |
| Late preterm (34-36 weeks) | 168 | 2.98 (2.45 to 3.61) | <0.001 |
| Early term (37-38 weeks) | 263 | 1.66 (1.41 to 1.96) | <0.001 |
| Full term (39-41 weeks) | 359 | Reference | — |
| Post-term (≥42 weeks) | 41 | 0.99 (0.72 to 1.37) | 0.96 |
| Per additional week (trend) | — | 0.84 (0.82 to 0.86) | <0.001 |
| Other causes | |||
| Preterm (<37 weeks) | 2971 | 1.53 (1.47 to 1.59) | <0.001 |
| Extremely preterm (22-27 weeks) | 142 | 1.94 (1.64 to 2.29) | <0.001 |
| Very preterm (28-33 weeks) | 810 | 1.77 (1.65 to 1.90) | <0.001 |
| Late preterm (34-36 weeks) | 2019 | 1.43 (1.36 to 1.50) | <0.001 |
| Early term (37-38 weeks) | 5865 | 1.16 (1.13 to 1.20) | <0.001 |
| Full term (39-41 weeks) | 14 391 | Reference | — |
| Post-term (≥42 weeks) | 1580 | 1.04 (0.99 to 1.10) | 0.13 |
| Per additional week (trend) | — | 0.94 (0.94 to 0.95) | <0.001 |
*
Adjusted for maternal age, year of delivery, parity, education, employment, income, region of origin, body mass index, smoking, pre-eclampsia, other hypertensive disorders, diabetes, asthma, rheumatoid arthritis, and depression.