Table 2.
Comparison of pregnancy outcomes among the four groups.
| Outcome | Control group (n = 437,382) | Women with α-thalassemia trait | P1* (P2†) | ||
|---|---|---|---|---|---|
| Normal fetal group (n = 446) | Fetal group with α-thalassemia trait (n = 708) | Fetal group with HbH disease (n = 211) | |||
| Cesarean delivery | 127,851 (29.23) | 137 (30.72) | 208 (29.38) | 63 (29.86) | 0.889 (.914) |
| Postpartum hemorrhage | 14,232 (3.25) | 24 (5.38) | 30 (4.24) | 9 (4.27) | 0.643 (.026) |
| Birth before 34 weeks of gestation | 5221 (1.19) | 8 (1.79) | 6 (0.85) | 4 (1.90) | 0.283 (.398) |
| Birth before 37 weeks of gestation | 25,205 (5.76) | 25 (5.61) | 48 (6.78) | 17 (8.06) | 0.477 (.333) |
| Fetal growth restriction | 9198 (2.10) | 7 (1.57) | 15 (2.12) | 6 (2.84) | 0.551 (.758) |
| Low birth weight | 22,695 (5.19) | 23 (5.16) | 40 (5.65) | 19 (9.00) | 0.129 (.088) |
| Macrosomia | 12,986 (2.97) | 13 (2.91) | 27 (3.81) | 6 (2.84) | 0.640 (.622) |
| Apgar score < 7 at 1 min | 4034 (0.92) | 7 (1.57) | 9 (1.27) | 10 (4.74) | 0.004 (< .001) |
| Apgar score < 7 at 5 min | 1918 (0.44) | 3 (0.67) | 1 (0.14) | 6 (2.84) | 0.001 (.001) |
| Perinatal death | 1874 (0.43) | 1 (0.22) | 1 (0.14) | 2 (0.95) | 0.147 (.359) |
Data are n (%) unless otherwise specified. *Chi-squared or Fisher–Freeman–Halton exact test for three subgroups. †Chi-squared or Fisher–Freeman–Halton exact test for all groups.