Table 3.
Adjusted hazard ratios for risk of all cause and cause specific premature mortality (before age 70), according to age at first spontaneous abortion in 101 681 women (Nurses’ Health Study II, 1993-2017)
| Age at first abortion | No of events | Crude incidence per 1000 person years | Adjusted hazard ratios (95% CI) | |||
|---|---|---|---|---|---|---|
| Age adjusted model* | Multivariable model 1† | Multivariable model 2‡ | Multivariable model 3§ | |||
| All deaths | ||||||
| None | 2192 | 1.24 | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) |
| ≥30 | 274 | 1.09 | 0.93 (0.82 to 1.05) | 1.00 (0.87 to 1.14) | 1.08 (0.95 to 1.24) | 1.12 (0.98 to 1.28) |
| 24-29 | 254 | 1.17 | 0.97 (0.85 to 1.10) | 1.06 (0.92 to 1.21) | 1.16 (1.01 to 1.34) | 1.16 (1.01 to 1.33) |
| ≤23 | 216 | 1.69 | 1.27 (1.11 to 1.46) | 1.39 (1.20 to 1.60) | 1.41 (1.21 to 1.63) | 1.32 (1.14 to 1.53) |
| P for trend | — | — | 0.06 | <0.001 | <0.001 | <0.001 |
| Deaths from cardiovascular disease | ||||||
| None | 189 | 0.11 | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) |
| ≥30 | 23 | 0.09 | 0.93 (0.60 to 1.43) | 1.02 (0.65 to 1.60) | 1.07 (0.68 to 1.68) | 1.15 (0.73 to 1.82) |
| 24-29 | 30 | 0.14 | 1.34 (0.91 to 1.97) | 1.49 (0.99 to 2.25) | 1.60 (1.05 to 2.42) | 1.59 (1.05 to 2.41) |
| ≤23 | 27 | 0.21 | 1.85 (1.23 to 2.77) | 2.04 (1.33 to 3.14) | 1.93 (1.25 to 2.98) | 1.78 (1.15 to 2.76) |
| P for trend | — | — | 0.004 | <0.001 | 0.001 | 0.002 |
| Deaths from cancer | ||||||
| None | 1020 | 0.58 | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) |
| ≥30 | 145 | 0.58 | 1.05 (0.88 to 1.25) | 1.08 (0.90 to 1.30) | 1.21 (1.00 to 1.45) | 1.20 (1.00 to 1.45) |
| 24-29 | 102 | 0.47 | 0.82 (0.67 to 1.01) | 0.85 (0.69 to 1.06) | 0.96 (0.77 to 1.19) | 0.95 (0.76 to 1.17) |
| ≤23 | 79 | 0.62 | 1.00 (0.79 to 1.25) | 1.03 (0.81 to 1.31) | 1.10 (0.86 to 1.39) | 1.05 (0.83 to 1.34) |
| P for trend | — | — | 0.34 | 0.65 | 0.54 | 0.75 |
| All other causes of death | ||||||
| None | 983 | 0.56 | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) |
| ≥30 | 106 | 0.42 | 0.80 (0.65 to 0.97) | 0.90 (0.73 to 1.10) | 0.96 (0.77 to 1.18) | 1.01 (0.82 to 1.24) |
| 24-29 | 122 | 0.56 | 1.04 (0.86 to 1.26) | 1.20 (0.99 to 1.47) | 1.32 (1.08 to 1.61) | 1.33 (1.09 to 1.63) |
| ≤23 | 110 | 0.86 | 1.45 (1.19 to 1.77) | 1.66 (1.35 to 2.05) | 1.64 (1.33 to 2.02) | 1.53 (1.24 to 1.89) |
| P for trend | — | — | 0.01 | <0.001 | <0.001 | <0.001 |
Age in months (continuous) at the start of follow-up and calendar year of the current questionnaire cycle were included as stratification variables.
Multivariable model 1 was further adjusted for time varying gravidity (1, 2, 3, or ≥4).
Multivariable model 2 was further adjusted for white race or ethnicity (no or yes) and pre-pregnancy body mass index (<25, 25-29.9, or ≥30), and time varying nulliparity (no or yes), marriage status (never v ever or currently married), history of gestational diabetes (no or yes), hypertensive disorders of pregnancy (no or yes), menopausal status (premenopausal, postmenopausal, or unsure or biologically uncertain), use of hormone treatment (never, past, or current), daily use of aspirin (no or yes), and parental history of myocardial infarction or stroke (no or yes).
Multivariable model 3 was further adjusted for time varying current body mass index (<23, 23-24.9, 25-29.9, or ≥30), smoking status (never, former, current 1-34 cigarettes/day, or current ≥35 cigarettes/day), physical activity (0, 0.1-1.0, 1.1-2.4, 2.5-5.9, or ≥6 hours/week), and Alternative Healthy Eating Index 2010 dietary score (five categories).