TABLE 2.
Overview of cohort studies: main findings1
| Study (reference) | Procedure | Study population | Main findings |
| Bebber et al. (13) | RYGB | 39 pregnancies (9 miscarriages) | Vitamin B-12: low (<175 pg/mL) in 53% (n = 16/31) of the women in T1 |
| Folic acid: low (4–17 μg/L) in 16% (n = 5/31) of the women in T1 | |||
| Dao et al. (14) | RYGB | 21 early pregnancies (<1 y after surgery) | Iron: deficiency in 1 patient of early group |
| 13 late pregnancies (≥1 y after surgery) | |||
| Devlieger et al. (20) | Mixed | 49 pregnancies | Vitamin A: deficiency (<300 μ/L) in 19% (T1) and 58% (T3) of the women |
| Vitamin B-12: deficiency (<191 ng/L) in 35% (T1) and 41% (T3) of the women | |||
| Folic acid: deficiency (<252 μg/L) in 3% (T1) and 0% (T3) of the women | |||
| Thiamin: deficiency (<70 nmol/L) in 2% (T1) and 17% (T3) of the women | |||
| 25(OH)D: severe deficiency (<7 μg/L) in 14% (T1) and 6% (T3) of the women | |||
| 25(OH)D: mild deficiency (7–20 μg/L) in 26% (T1) and 36% (T3) of the women | |||
| Ferritin: deficiency (<30 μg/L) in 27% (T1) and 42% (T3) of the women | |||
| No association between supplement intake and deficiencies | |||
| One women was diagnosed with an NTD | |||
| Dixon et al. (17) | AGB | 79 consecutive first pregnancies | No specific nutritional deficiencies |
| 84% of the women reported daily intake of multivitamin | |||
| Faintuch et al. (18) | RYGB | 14 pregnancies | Iron: occasional low values in T2 (78 ± 50 μg/dL; RV: 37–145 μg/dL) |
| Vitamin B-12: occasional low values in T2 (193 ± 102 μg/dL; RV 180–914 μg/dL) | |||
| Gadgil et al. (16) | Mixed | 456 pregnancies after surgery | Vitamin B-12: deficiency in 12% after surgery vs. 2% before surgery |
| 338 pregnancies before surgery | Folate: deficiency in 7% after surgery vs. 1% before surgery | ||
| Vitamin D: deficiency in 3% after surgery vs. 0% before surgery | |||
| Iron: deficiency in 9% after surgery vs. 2% before surgery | |||
| Jans et al. (19) | Mixed | 49 pregnancies | Phylloquinone: lower in surgical (0.44 nmol/L) vs. nonsurgical (0.65 nmol/L) group in T1 |
| 27 pregnancies without surgery | For study group higher in T3 (4.7 nmol/L) vs. T1 (0.42 nmol/L) | ||
| Nomura et al. (15) | RYGB | 17 pregnancies <4 y after RYGB | Anemia: defined as hemoglobin <11 g/dL |
| 13 pregnancies ≥4 y after RYGB | More i.v. iron in late (30.8%) vs. early (0%) group (P = 0.026) |
1
AGB, adjustable gastric banding; NTD, neural tube defect; RYGB, Roux-en-Y gastric bypass; RV, reference value; T1, first trimester of pregnancy; T2, second trimester of pregnancy; T3, third trimester of pregnancy; 25(OH)D, 25-hydroxyvitamin D.