Table 1.
Characteristics of Case subjects and Control Subjects at Enrollment
| Characteristic | Case subjects (n = 136) | Control Subjects (n = 331) | P |
|---|---|---|---|
| Age (years) median (IQR) | 24.5 (20–30.5) | 26 (21–31) | .1 |
| Gravidity, median (IQR) | 3 (2–5) | 3 (2–5) | .36 |
| Primigravida, n (%) | 30 (22.1) | 52 (15.7) | .10 |
| Multigravida, n (%) | 106 (77.9) | 279 (84.3) | |
| Parity, median (IQR) | 1 (0–3) | 2 (2–5) | .09 |
| Hematocrit (%), median (IQR) | 32.55 (30–35) | 34.5 (32–36.6) | <.001 |
| Anemiaa, n (%) | 32 (23.5) | 39 (11.8) | .001 |
| Residence in refugee camp | 61 (44.9) | 324 (97.9) | <.001 |
| Receiving chloroquine prophylaxis, n (%) | 56 (41.2) | 168 (50.8) | .06 |
| Estimated Gestational Ageb, median (IQR) | 9.8 (7.0–13.9) | 9.6 (7.6–11.6) | .45 |
| Trimester | |||
| 1 (<14 wk) | 101 (75.0) | 289 (87.3) | .001c |
| 2 (14 to <28 wk) | 32 (23.5) | 42 (12.7) | |
| 3 (28 wk or more) | 2 (1.5) | 0 (0) | |
| Plasmodium species before enrollmentd, n (%) | 76 (55.9) | 117 (35.3) | <.001 |
| P. falciparum | |||
| Proportion women infected, n (%) | 51 (38.3) | 82 (24.8) | .003 |
| Number of episodes, median (IQR) | 1 (1–4) | 1 (1–4) | .89 |
| P. vivax | |||
| Proportion women infected, n (%) | 33 (24.8) | 46 (13.9) | .005 |
| Number of episodes, median [IQR] | 1 (1–3) | 1 (1–3) | .12 |
| Follow up (weeks), median (range) | 28.9 (23.3–32.2) | 30.7 (28.3–32.4) | <.001 |
| Plasmodium screens during pregnancy, median [IQR] | 26 (19–30) | 30 (27–32) | <.001 |
The associations between categorical variables were assessed by χ2 tests or Fisher's exact tests and continuous variables by Mann-Whitney U tests, Wilcoxon signed-rank tests, or t tests.
Abbreviation: IQR, inter-quartile range.
a Haematocrit <30%.
b Determined at enrollment.
c Statistical comparison is first vs second and third trimester (combined).
d Any microscopically confirmed Plasmodium infection documented at SMRU before enrollment into the study.