Estimates of national prevalence of alloimmunization in early pregnancy
| Risk of HDFN . | Rate per 100 000 pregnancies (95% CI) . | |
|---|---|---|
| Pregnancies . | ||
| (n = 9 876 196) . | ||
| RBC ab detected . | Critical titer∗ . | |
| High risk | ||
| Anti-D | 586 (553-618) | 21 (20-22) |
| Anti-K | 68 (64-71) | 46 (44-48) |
| Anti-c | 29 (26-31) | 1.9 (1.5-2.2) |
| Any† | 679 (645-714) | 69 (66-71) |
| Moderate risk | ||
| Anti-E | 110 (105-116) | 8 (7-9) |
| Anti-C | 30 (26-33) | 2.6 (2.2-3.0) |
| Anti-e | 4 (3-5) | 0.06 (0.01-0.12) |
| Anti-k | 0.01 (0-0.03) | 0.01 (0-0.03) |
| Anti-Fya | 13 (12-14) | 3.1 (2.7-3.6) |
| Anti-U | 0.03 (0-0.07) | 0 |
| Any‡ | 123 (116-130) | 6.8 (5.8-7.7) |
| Low risk∗∗ | ||
| Any | 112 (103-121) | Not applicable |
| Risk of HDFN . | Rate per 100 000 pregnancies (95% CI) . | |
|---|---|---|
| Pregnancies . | ||
| (n = 9 876 196) . | ||
| RBC ab detected . | Critical titer∗ . | |
| High risk | ||
| Anti-D | 586 (553-618) | 21 (20-22) |
| Anti-K | 68 (64-71) | 46 (44-48) |
| Anti-c | 29 (26-31) | 1.9 (1.5-2.2) |
| Any† | 679 (645-714) | 69 (66-71) |
| Moderate risk | ||
| Anti-E | 110 (105-116) | 8 (7-9) |
| Anti-C | 30 (26-33) | 2.6 (2.2-3.0) |
| Anti-e | 4 (3-5) | 0.06 (0.01-0.12) |
| Anti-k | 0.01 (0-0.03) | 0.01 (0-0.03) |
| Anti-Fya | 13 (12-14) | 3.1 (2.7-3.6) |
| Anti-U | 0.03 (0-0.07) | 0 |
| Any‡ | 123 (116-130) | 6.8 (5.8-7.7) |
| Low risk∗∗ | ||
| Any | 112 (103-121) | Not applicable |
CI, confidence interval.
≥4 for anti-K and ≥16 for all other high-risk and moderate-risk abs.
Includes: anti-Cw, anti-f, anti-Jka, anti-Jkb, anti-M, anti-S, anti-s, anti-Fyb, anti-Lua, anti-Lub, anti-Kpa, anti-Kpb, anti-Yta, anti-Coa, anti-Cob, anti-Ge2,3.
Accounted for any high-risk antibody combination detected in a test (0.3%).
Accounted for any moderate-risk ab combination detected in a test (0.5%) and excluded those combinations with high-risk abs (3.1%).