Table 2 Hb levels at early, mid-, and late pregnancy and birth outcomes stratified by tertiles of Hb changes from early to late pregnancy (n = 1986) a, b
From: Changes in maternal hemoglobin during pregnancy and birth outcomes
Variable | Total (n = 1986) | Greatest reduction (Hb change < −1.9) (n = 639) | Intermediate reduction (−1.9 ≤ Hb change < −1.0) (n = 689) | Least reduction (Hb change ≥ −1.0) (n = 658) |
|---|---|---|---|---|
Early pregnancy (<16 weeks) | ||||
Hb, (g/dL) | 12.5 (0.88) | 13.0 (0.73) | 12.5 (0.75) | 12.0 (0.87) |
Anemia (<11 g/dL), n (%) | 89 (4.5) | 4 (0.63) | 14 (2.0) | 70 (10.6) |
Gestational age at measurement, (weeks) | 11.4 (2.0) | 11.0 (1.9) | 11.4 (1.9) | 11.7 (2.0) |
Iron supplement intake | 12 (0.60) | 0 (0) | 1 (0.15) | 11 (1.7) |
Mid-pregnancy (16–27 weeks) | ||||
Hb, (g/dL) | 11.0 (0.86) | 11.1 (0.79) | 11.1 (0.83) | 11.0 (0.95) |
Anemia (<11 g/dL), n (%) | 876 (44.1) | 276 (43.2) | 288 (41.8) | 312 (47.4) |
Gestational age at measurement, (weeks) | 24.7 (1.5) | 24.6 (1.5) | 24.7 (1.6) | 24.8 (1.5) |
Iron supplement intake | 290 (14.6) | 59 (9.2) | 79 (11.5) | 152 (23.1) |
Late pregnancy (28–37 weeks) | ||||
Hb, (g/dL) | 11.1 (0.96) | 10.4 (0.79) | 11.0 (0.77) | 11.7 (0.84) |
Anemia (<11 g/dL), n (%) | 907 (45.7) | 473 (74.0) | 316 (45.9) | 118 (17.9) |
Gestational age at measurement, (weeks) | 35.4 (1.3) | 35.3 (1.4) | 35.4 (1.3) | 35.5 (1.2) |
Iron supplement intake | 408 (20.5) | 228 (35.7) | 102 (14.8) | 78 (11.9) |
Pregnancy complication | ||||
Pregnancy-induced hypertension, n (%) | 44 (2.2) | 15 (2.3) | 14 (2.0) | 15 (2.3) |
Delivery outcomes | ||||
Gestational age of delivery, (week) | 39.1 (1.3) | 39.1 (1.3) | 39.3 (1.2) | 39.3 (1.3) |
Preterm birth, n (%) | 68 (3.4) | 24 (3.8) | 22 (3.2) | 22 (3.3) |
Mode of delivery | ||||
Normal vaginal delivery, n (%) | 1205 (60.7) | 367 (57.4) | 422 (61.2) | 416 (63.2) |
Forceps or vacuum delivery, n (%) | 297 (15.0) | 97 (15.2) | 105 (15.2) | 95 (14.4) |
Cesarean section, n (%) | 484 (24.4) | 175 (27.4) | 162 (23.5) | 147 (22.3) |
Sex (male), n (%) | 1029 (51.8) | 322 (50.4) | 363 (52.7) | 344 (52.3) |
Birth weight, (g) | 3016 (370) | 3068 (354) | 3032 (369) | 2947 (386) |
Z-score of birth weight | 0.078 (0.94) | 0.27 (0.89) | 0.096 (0.93) | −0.13 (0.95) |
Low birth weight, n (%) | 132 (6.6) | 32 (5.0) | 38 (5.5) | 62 (9.4) |
Small for gestational age, n (%)c | 139 (7.0) | 22 (3.4) | 51 (7.4) | 66 (10.0) |
Placental weight, (g) | 546 (101) | 572 (101) | 545 (100) | 523 (98) |
Placental ratio | 0.18 (0.027) | 0.19 (0.029) | 0.18 (0.026) | 0.18 (0.026) |
High placental ratio, n (%)d | 192 (9.7) | 87(13.6) | 60 (8.7) | 45 (6.8) |