Table 1.
Characteristics of pregnancies among patients in the pregnant cohort (n = 333)
| Characteristics | All patients(n = 333) No. (%) | ER-positive patients (n = 194) No. (%) | ER-negative patients (n = 139) No. (%) | P* |
|---|---|---|---|---|
| Pregnancy outcome | ||||
| Completed pregnancy | 188 (56.5) | 110 (56.7) | 78 (56.1) | .69 |
| Abortion | 135 (40.5) | 76 (39.2) | 59 (42.5) | |
| Induced abortion† | 91 (67.4) | 53 (69.7) | 38 (64.4) | |
| Spontaneous abortion† | 22 (16.3) | 12 (15.8) | 10 (17.0) | |
| Unknown† | 22 (16.3) | 11 (14.5) | 11 (18.6) | |
| Unknown | 10 (3.0) | 8 (4.1) | 2 (1.4) | |
| Pregnancy interval | ||||
| <2 y from diagnosis | 140 (42.0) | 73 (37.6) | 67 (48.2) | .06 |
| ≥2 y from diagnosis | 193 (58.0) | 121 (62.4) | 72 (51.8) | |
| 2–5 y‡ | 139 (72.0) | 77 (63.6) | 62 (86.1) | |
| >5 y‡ | 54 (28.0) | 44 (36.4) | 10 (13.9) | |
| Breastfeeding status§ | ||||
| Yes | 25 (13.3) | 21 (19.1) | 4 (5.1) | .05 |
| No | 39 (20.7) | 23 (20.9) | 16 (20.5) | |
| Unknown | 124 (66.0) | 66 (60.0) | 58 (74.4) |
Chi-square test or Fisher’s exact test with two-sided P values for the comparison between ER-positive and ER-negative patients calculated by excluding unknown data. ER = estrogen receptor.
Percentages calculated on the total number of patients with abortion (135 in all patients, 76 in women with ER-positive breast cancer, and 59 in those with ER-negative disease).
Percentages calculated on the total number of patients who became pregnant two or more years from diagnosis (193 in all patients, 121 in women with ER-positive breast cancer, and 72 in those with ER-negative disease).
Percentages calculated on the total number of patients with completed pregnancy (188 in all patients, 110 in women with ER-positive breast cancer, and 78 in those with ER-negative disease).