Reproductive factors | One woman per family cohort: 39,666 person-years of follow-up | BRCA1mutation carriers: 25,045 person-years of follow-up | BRCA2mutation carriers: 14,621 person-years of follow-up | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 |  | Person-yearsa | No. of casesa | HR | 95% CI | Pvalue | Person-yearsa | No. of casesa | HR | 95% CI | Pvalue | Person-yearsa | No. of casesa | HR | 95% CI | Pvalue |
Incomplete pregnancies b | ||||||||||||||||
 | Never | 33,455 | 219 | 1.00 |  |  | 21,291 | 135 | 1.00 |  |  | 12,164 | 84 | 1.00 |  |  |
 | Ever | 5,995 | 155 | 1.28 | 0.98-1.67 | 0.07 | 3,673 | 103 | 1.30 | 0.95-1.76 |  | 2,322 | 52 | 1.07 | 0.64-1.78 |  |
No. of incomplete pregnancies b | ||||||||||||||||
 | 0 | 33,455 | 219 | 1.00 |  |  | 21,291 | 135 | 1.00 |  |  | 12,164 | 84 | 1.00 |  |  |
 | 1 | 4,208 | 103 | 1.25 | 0.93-1.69 |  | 2,544 | 70 | 1.27 | 0.89-1.82 |  | 1,664 | 33 | 0.96 | 0.53-1.73 |  |
 | 2 | 1,320 | 32 | 1.07 | 0.69-1.66 |  | 841 | 21 | 1.08 | 0.65-1.79 |  | 479 | 11 | 1.01 | 0.46-2.24 |  |
 | ≥3 | 467 | 20 | 2.39 | 1.28-4.45 | 0.01 | 288 | 12 | 2.45 | 1.19-5.04 | 0.02 | 179 | 8 | 2.69 | 0.71-10.3 |  |
 | Trend |  |  | 1.19 | 1.02-1.39 | 0.03 |  |  | 1.20 | 1.00-1.43 | 0.05 |  |  | 1.15 | 0.84-1.58 |  |
Type of incomplete pregnancies b | ||||||||||||||||
 | No incomplete pregnancies | 33,384 | 219 | 1.00 |  |  | 21,220 | 135 | 1.00 |  |  | 12,164 | 84 | 1.00 |  |  |
 | Induced abortion only | 2,909 | 71 | 1.29 | 0.93-1.81 |  | 1,859 | 50 | 1.35 | 0.92-1.99 |  | 1,050 | 21 | 1.02 | 0.53-1.96 |  |
 | Miscarriage only | 2,494 | 65 | 1.19 | 0.83-1.72 |  | 1,407 | 41 | 1.14 | 0.73-1.78 |  | 1,087 | 24 | 1.05 | 0.54-2.04 |  |
 | Induced abortion and miscarriage | 535 | 18 | 1.49 | 0.84-2.65 |  | 350 | 11 | 1.51 | 0.79-2.91 |  | 185 | 7 | 1.43 | 0.45-4.51 |  |
No. of induced abortionsb | ||||||||||||||||
 | 0 | 35,968 | 286 | 1.00 |  |  | 22,666 | 177 | 1.00 |  |  | 13,302 | 109 | 1.00 |  |  |
 | 1 | 2,833 | 66 | 1.15 | 0.83-1.60 |  | 1,805 | 47 | 1.22 | 0.84-1.78 |  | 1,028 | 19 | 0.87 | 0.45-1.68 |  |
 | 2 | 497 | 16 | 1.44 | 0.74-2.78 |  | 322 | 10 | 1.59 | 0.75-3.40 |  | 175 | 6 | 1.47 | 0.44-4.88 |  |
 | ≥3 | 114 | 7 | 3.84 | 1.52-9.66 | <10-3 | 82 | 4 | 3.31 | 1.13-9.71 | 0.03 | 32 | 3 | 7.85 | 1.74-35.5 | 0.01 |
 | Trend |  |  | 1.28 | 1.04-1.58 | 0.02 |  |  | 1.32 | 1.04-1.67 | 0.02 |  |  | 1.26 | 0.81-1.95 |  |
No. of miscarriagesb | ||||||||||||||||
 | 0 | 36,419 | 293 | 1.00 |  |  | 23,121 | 186 | 1.00 |  |  | 13,298 | 107 | 1.00 |  |  |
 | 1 | 2,273 | 64 | 1.21 | 0.85-1.72 |  | 1,321 | 41 | 1.20 | 0.79-1.82 |  | 952 | 23 | 1.01 | 0.50-2.02 |  |
 | 2 | 508 | 12 | 0.98 | 0.48-1.99 |  | 301 | 6 | 0.69 | 0.27-1.81 |  | 207 | 6 | 1.54 | 0.64-3.67 |  |
 | ≥3 | 248 | 7 | 1.18 | 0.42-3.30 |  | 135 | 5 | 1.40 | 0.44-4.53 |  | 113 | 2 | 0.86 | 0.10-7.56 |  |
 | Trend |  |  | 1.07 | 0.87-1.32 |  |  |  | 1.04 | 0.81-1.35 |  |  |  | 1.09 | 0.75-1.58 |  |
Age at first induced abortionc | ||||||||||||||||
 | <20 years | 1,094 | 32 | 1.00 |  |  | 662 | 20 | 1.00 |  |  | 432 | 12 | 1.00 |  |  |
 | ≥ 20 years | 2,350 | 57 | 0.50 | 0.28-0.90 | 0.02 | 1,547 | 41 | 0.53 | 0.27-1.02 | 0.06 | 803 | 16 | 0.40 | 0.10-1.53 |  |
 | No induced abortion | 35,968 | 286 | 0.74 | 0.31-1.78 |  | 22,666 | 177 | 0.70 | 0.27-1.84 |  | 13,302 | 109 | 1.10 | 0.12-10.5 |  |
Age at first miscarriagec | ||||||||||||||||
 | <20 years | 220 | 5 | 1.00 |  |  | 202 | 5 | 1.00 |  |  | 18 | 0 |  |  |  |
 | ≥ 20 | 2,809 | 78 | 1.04 | 0.25-4.28 |  | 1,555 | 47 | 0.87 | 0.20-3.73 |  | 1,254 | 31 |  |  |  |
 | No miscarriage | 36,419 | 293 | 0.81 | 0.17-3.99 |  | 23,121 | 186 | 0.69 | 0.12-3.93 |  | 13,298 | 107 |  |  |  |
Induced abortion relative to the first full-term pregnancyb | ||||||||||||||||
 | No induced abortion | 35,964 | 284 | 1.00 |  |  | 22,663 | 175 | 1.00 |  |  | 13,301 | 109 | 1.00 |  |  |
 | Before first full-term pregnancy | 1,835 | 49 | 1.77 | 1.19-2.63 | 0.01 | 1,223 | 33 | 1.77 | 1.13-2.77 | 0.01 | 612 | 16 | 1.88 | 0.86-4.12 |  |
 | After first full-term pregnancy | 1,613 | 42 | 0.97 | 0.65-1.45 |  | 989 | 30 | 1.14 | 0.72-1.79 |  | 624 | 12 | 0.55 | 0.26-1.18 |  |
Miscarriage relative to the first full-term pregnancyb 1.00 | ||||||||||||||||
 | No miscarriage | 36,414 | 291 |  |  |  | 23,118 | 186 | 1.00 |  |  | 13,296 | 105 | 1.00 |  |  |
 | Before first full-term pregnancy | 1,138 | 29 | 1.07 | 0.65-1.77 |  | 729 | 20 | 1.01 | 0.55-1.84 |  | 409 | 9 | 0.89 | 0.36-2.16 |  |
 | After first full-term pregnancy | 1,896 | 56 | 1.05 | 0.73-1.51 |  | 1,031 | 32 | 1.02 | 0.65-1.60 |  | 865 | 24 | 1.09 | 0.57-2.08 |  |
Type and length of incomplete pregnanciesb | ||||||||||||||||
 | No abortion | 33,384 | 219 | 1.00 |  |  | 21,220 | 135 | 1.00 |  |  | 12,164 | 84 | 1.00 |  |  |
 | Induced abortion only | 2,909 | 71 | 1.30 | 0.93-1.82 |  | 1,859 | 50 | 1.36 | 0.92-2.00 |  | 1,050 | 21 | 1.01 | 0.52-1.95 |  |
 | Miscarriage with length ≤3 months | 2,492 | 74 | 1.35 | 0.95-1.93 | 0.09 | 1,461 | 45 | 1.27 | 0.84-1.94 |  | 1,031 | 29 | 1.35 | 0.69-2.67 |  |
 | Miscarriage with length >3 months | 436 | 8 | 0.93 | 0.41-2.12 |  | 253 | 7 | 1.17 | 0.47-2.95 |  | 183 | 1 | 0.14 | 0.02-1.24 | 0.08 |
TMAP score (not including never pregnant women)d | ||||||||||||||||
 | ]0-0.35] | 7,545 | 141 | 1.00 |  |  | 4,564 | 85 | 1.00 |  |  | 2,981 | 56 | 1.00 |  |  |
 | ]0.35-0.40] | 3,416 | 88 | 1.05 | 0.75-1.48 |  | 2,154 | 59 | 0.99 | 0.66-1.48 |  | 1,262 | 29 | 1.09 | 0.60-1.98 |  |
 | ]0.40-0.45] | 1,735 | 51 | 1.23 | 0.81-1.86 |  | 1,034 | 30 | 1.12 | 0.67-1.87 |  | 701 | 21 | 1.33 | 0.68-2.59 |  |
 | ]0.45-0.50] | 589 | 17 | 1.53 | 0.80-2.93 |  | 433 | 14 | 1.41 | 0.68-2.92 |  | 156 | 3 | 1.70 | 0.37-7.71 |  |
 | ]0.5-1.00] | 1,186 | 22 | 1.97 | 1.19-3.29 | 0.01 | 722 | 12 | 1.91 | 1.07-3.42 | 0.03 | 464 | 10 | 2.04 | 0.79-5.24 |  |
 | Trend |  |  | 1.16 | 1.03-1.30 | 0.02 |  |  | 1.14 | 0.99-1.32 | 0.07 |  |  | 1.17 | 0.95-1.44 |  |