Table 1.
Characteristics of study participants at enrollment. All data are shown as a number (%) unless otherwise indicated
| Characteristic at enrollment |
Magnesium citrate (n = 407) |
Placebo (n = 422) |
P-value |
|---|---|---|---|
| Mean (SD) maternal age, years | 26.9 (5.4) | 27.2 (5.8) | 0.53 |
| Mean (SD) gestational age at entry, weeks | 15.1 (3.6) | 15.6 (3.8) | 0.05 |
| Lives with partner | 211 (51.8) | 188 (44.5) | 0.04 |
| Completed schooling beyond grade 8 | 379 (93.3) | 388 (91.9) | 0.44 |
| Currently employed | 221 (54.3) | 220 (52.1) | 0.53 |
| Alcohol use disorder | 8 (2.0) | 12 (2.8) | 0.41 |
| Current smoker | 5 (1.2) | 11 (2.6) | 0.15 |
| Current illicit drug use | 3 (0.7) | 5 (1.2) | 0.73 |
| Pre-pregnancy body mass index, kg/m2 | |||
| < 18.5 | 13 (3.2) | 11 (2.6) | 0.89 |
| 18.5 to 24.9 | 162 (39.8) | 171 (40.7) | |
| 25.0 to 29.9 | 136 (33.4) | 146 (34.8) | |
| ≥ 30.0 | 96 (23.6) | 92 (21.9) | |
| Pre-pregnancy chronic hypertension | 50 (22.1) | 60 (24.4) | 0.59 |
| Gestational diabetes mellitus in a previous pregnancy | 11 (4.9) | 18 (7.3) | 0.27 |
| Preterm birth in a previous pregnancy | 38 (9.6) | 38 (9.3) | 0.87 |
| Mean (SD) serum magnesium concentration, mg/dL | 1.8 (0.2) | 1.8 (0.2) | 0.94 |
| Serum magnesium deficiency < 1.8 mg/dL | 194 (47.9) | 219 (52.1) | 0.22 |
| Mean (SD) serum creatinine concentration, mg/dL | 0.5 (0.2) | 0.5 (0.1) | 0.80 |