Table 1. Comparison of variables, including age, CD4 counts, and reproductive and medical history, for HIV-negative and HIV-positive study participants, Malawi, 2008–2010*.
| Variable | All study participants, N = 1,857† | HIV-positive participants, n = 402/21.7% | HIV-negative participants, n = 1,454/78.3% | p value |
|---|---|---|---|---|
| Mean age, y (SD) | 25.2 (5.9) | 26.7 (5.5) | 24.8 (5.9) | <0.001 |
| No. (%) recruited during wet season (Nov–Mar) |
1,057 (57.0) |
234 (58.2) |
820 (56.4) |
0.57 |
| Reproductive and medical history | ||||
| Pregnancies, median no. (range) | 1 (0–10) | 2 (0–8) | 1 (0–10) | <0.001 |
| Live births, median no. (range) | 1 (0–10) | 1 (0–7) | 1 (0–10) | <0.001 |
| Previous neonatal death, no. (%) | 45 (2.4) | 11 (2.7) | 34 (2.3) | 0.65 |
| Median time since LMP, days (range) | 275 (98–371) | 275 (145–371) | 276 (98–370) | 0.17 |
| Unwell at labor ward attendance, no. (%) | 114 (6.1) | 33 (8.2) | 81 (5.6) | 0.05 |
| Membranes ruptured >18 h before enrolled, no. (%) | 52 (2.8) | 12 (3.0) | 40 (2.8) | 0.79 |
| Previous HIV test, no. (%) | 1,664 (89.7) | 368 (91.5) | 1,296 (89.1) | 0.16 |
| Taking ART, no. (%) | – | 83 (20.7) | – | |
| Median duration of ART, mo (range) | 4 (1–144) | |||
| Genital ulcer disease, no. (%) | 46 (2.5) | 32 (8.0) | 14 (1.0) | <0.001 |
| Sexually transmitted disease, no. (%) | 34 (1.8) | 23 (5.7) | 11 (0.8) | <0.001 |
| S-P use during last 4 wk of pregnancy, no. (%) |
1,779 (96.0) |
379 (94.3) |
1,395 (96.9) |
0.38 |
| Examination and other findings | ||||
| First stage of labor, no. (%) | 1,298 (69.9) | 279 (69.4) | 1,019 (70.1) | 0.79 |
| Premature labor before 36 wk, no. (%) | 270 (14.5) | 71 (17.7) | 199 (13.7) | 0.04 |
| Registered for PMTCT on labor ward, no. (%) | – | 333 (82.8)‡ | – | |
| Mean birth weight (SD), kg | 2.90 (0.54) | 2.81 (0.58) | 2.91 (0.52) | <0.001 |
| Delivery by cesarean section, no. (%) | 383 (20.6) | 76 (18.9) | 307 (21.1) | 0.33 |
| Stillbirth, no. (%) | 30 (1.6) | 13 (3.2) | 17 (1.2) | 0.004 |
| Multiple birth, no. (%) |
50 (2.7) |
10 (2.5) |
40 (2.8) |
0.77 |
| Laboratory tests | ||||
| Plasma sample for CD4 count, no. | – | 383§ | – | |
| CD4 count, median (range) | 370 (20–1595) | |||
| No. failed samples¶ | 18 | 5 | 13 | |
| GBS isolated, no. (%)# | 390 (21.2) | 77 (19.4) | 313 (21.5) | 0.4 |
| Serotype | ||||
| 1a | 71 (18.2) | 11 (14.3) | 60 (19.2) | |
| 1b | 24 (6.2) | 1 (1.3) | 23 (7.4) | |
| 2 | 40 (10.3) | 9 (11.7) | 31 (9.9) | |
| 3 | 152 (39.0) | 32 (41.6) | 120 (38.3) | |
| 4 | 1 (0.3) | 0 | 1 (0.3) | |
| 5 | 93 (23.9) | 23 (29.9) | 70 (22.4) | |
| 6 (1 sample), 8 (2 samples) | 3 (0.8) | 0 | 3 (1.0) | |
| Untypeable, no (%) | 6 (1.5) | 1 (1.3) | 5 (1.6) |
*LMP, last menstrual period; ART, antiretroviral treatment; –, not applicable; S-P, sulfadoxine-pyrimethamine; PMTCT, prevention of mother-to-child transmission care; GBS, group B streptococcus. †Form for 1 participant was missing. ‡No. includes only participants confirmed as HIV-positive. §15 failures, 4 samples not obtained. ¶Contamination of the selective broth in 9 cases and incubator failure in 9 cases. #Failed samples excluded from denominator to derive percentage.