Table 1.
Demographic and baseline clinical characteristics of the study sample.
| Women with no recorded pregnancy | Women with incident pregnancy | Women with prevalent pregnancy | Total | |
| n (col %) | n (col %) | n (col %) | n (col %) | |
| N = 2403 | N = 1953 | N = 1950 | N = 6306 | |
| Average follow-up time, mean years (SD) | 1.6 (0.6) | 1.7 (0.5) | 1.5 (0.6) | 1.6 (0.6) |
| Race | ||||
| Black | 2334 (98.3) | 1917 (98.6) | 1896 (98.6) | 6147 (98.5) |
| Other | 41 (1.7) | 28 (1.4) | 27 (1.4) | 96 (1.5) |
| Age at delivery/baseline | ||||
| Under 25 | 289 (12.0) | 120 (6.1) | 323 (16.6) | 732 (11.6) |
| 25–29.9 | 669 (27.8) | 518 (26.5) | 689 (35.3) | 1876 (29.7) |
| 30–39.9 | 1327 (55.2) | 1223 (62.6) | 867 (44.5) | 3417 (54.2) |
| 40–49.9 | 118 (4.9) | 91 (4.7) | 71 (3.6) | 280 (4.4) |
| Highest level of education at ART initiation | ||||
| Primary school | 213 (9.2) | 143 (7.6) | 121 (6.4) | 477 (7.9) |
| Some secondary school | 528 (22.8) | 260 (13.8) | 525 (27.9) | 1313 (21.6) |
| Grade 12 completed | 971 (42.0) | 801 (42.7) | 627 (33.4) | 2399 (39.5) |
| Postmatric | 48 (2.1) | 53 (2.8) | 27 (1.4) | 128 (2.1) |
| No schooling | 552 (23.9) | 621 (33.1) | 580 (30.9) | 1753 (28.9) |
| Employment status at ART initiation | ||||
| Employed | 838 (36.8) | 680 (36.1) | 770 (41.9) | 2288 (38.1) |
| Unemployed | 1441 (63.2) | 1203 (63.9) | 1069 (58.1) | 3713 (61.9) |
| ART site | ||||
| Clinic in hospital complex | 1055 (43.9) | 1037 (53.1) | 510 (26.2) | 2602 (41.3) |
| Local primary care clinic | 949 (39.5) | 438 (22.4) | 593 (30.4) | 1980 (31.4) |
| NGO-run clinic | 398 (16.6) | 478 (24.5) | 847 (43.4) | 1723 (27.3) |
| Initial first-line ART regimen | ||||
| 3TC/FTC + TDF + EFV/NVP | 753 (31.3) | 309 (15.8) | 843 (43.2) | 1905 (30.2) |
| ZDV + 3TC + EFV/NVP | 146 (6.1) | 112 (5.7) | 355 (18.2) | 613 (9.7) |
| d4T + 3TC + EFV/NVP | 1491 (62.0) | 1530 (78.3) | 751 (38.5) | 3772 (59.8) |
| 3TC + ABC + EFV/NVP | 13 (0.5) | 2 (0.1) | 1 (0.1) | 16 (0.3) |
| ART regimen changes by the time of delivery (or equivalent matched time) | ||||
| First-line regimen preserved | 1927 (80.2) | 1049 (53.7) | 1826 (93.6) | 4802 (76.2) |
| First-line drug substitution | 346 (14.4) | 619 (31.7) | 50 (2.6) | 1015 (16.1) |
| Switched to second-line ART | 56 (2.3) | 219 (11.2) | 15 (0.8) | 290 (4.6) |
| Treatment interrupted | 74 (3.1) | 66 (3.4) | 59 (3.0) | 199 (3.2) |
| Among those who interrupted ART | ||||
| Overall length of treatment interruption, median months (IQR) | 12.7 (6.6–21.2) | 5.8 (3.9–11.4) | 5.7 (2.7–14.1) | 8.0 (4.1–16.2) |
| Period of ART interruption in pregnancy, median months (IQR) | 4.6 (1.4–9.0) | 0.6 (0–4.5) | 0 (0–0.5) | 1.0 (0–5.0) |
| Period of interruption after delivery, median months (IQR) | 6.3 (2.4–13.6) | 4.7 (3.0–7.3) | 6.3 (2.0–14.8) | 5.4 (2.4–12.8) |
| New regimen after treatment interruption | ||||
| 3TC/FTC + TDF + EFV/NVP | 32 (43.2) | 18 (27.7) | 25 (42.4) | 75 (37.9) |
| ZDV + 3TC + EFV/NVP | 3 (4.1) | 9 (13.9) | 6 (10.2) | 18 (9.1) |
| d4T + 3TC + EFV/NVP | 25 (33.8) | 19 (29.2) | 22 (37.3) | 66 (33.3) |
| Second-line (three ARVs with LPVr/ATVr) | 6 (8.1) | 16 (24.6) | 5 (8.5) | 27 (13.6) |
| Other | 8 (10.8) | 3 (4.6) | 1 (1.7) | 12 (6.1) |
| Time on ART before delivery (or equivalent matched time) | ||||
| 3 months or less | 563 (23.4) | 0 | 1390 (71.3) | 1953 (31.0) |
| 4–6 months | 432 (18.0) | 0 | 440 (22.6) | 872 (13.8) |
| 7–12 months | 428 (17.8) | 163 (8.3) | 120 (6.2) | 711 (11.3) |
| 13–24 months | 527 (21.9) | 862 (44.1) | 0 | 1389 (22.0) |
| 25 months or longer | 453 (18.9) | 928 (47.5) | 0 | 1381 (21.9) |
| BMI up to 3 months before or after delivery (or equivalent matched time) | ||||
| Underweight | 135 (7.5) | 21 (1.2) | 19 (1.1) | 175 (3.3) |
| Normal | 876 (48.7) | 570 (31.7) | 553 (31.6) | 1999 (37.4) |
| Overweight | 499 (27.8) | 719 (39.9) | 697 (39.8) | 1915 (35.8) |
| Obese | 288 (16.0) | 490 (27.2) | 483 (27.6) | 1261 (23.6) |
| Anaemic up to 3 months before or after delivery (or equivalent matched time) | ||||
| No | 1103 (70.4) | 1075 (73.7) | 777 (49.5) | 2955 (64.3) |
| Yes | 463 (29.6) | 383 (26.3) | 794 (50.5) | 1640 (35.7) |
| CD4+ cell count up to 3 months before or after delivery (or equivalent matched time) | ||||
| Under 200 | 464 (25.3) | 148 (9.9) | 462 (28.2) | 1074 (21.6) |
| 200–349 | 579 (31.6) | 420 (28.2) | 555 (33.9) | 1554 (31.3) |
| 350 or higher | 789 (43.1) | 923 (61.9) | 622 (38.0) | 2334 (47.0) |
| Unsuppressed viral load (≥50 copies/ml) up to 3 months before or after delivery (or equivalent matched time) | ||||
| No | 1149 (63.1) | 1054 (64.6) | 913 (55.7) | 3116 (61.2) |
| Yes | 672 (36.9) | 577 (35.4) | 726 (44.3) | 1975 (38.8) |
| Viral load ≥400 copies/ml up to 3 months before or after delivery (or equivalent matched time) | ||||
| No | 1464 (80.4) | 1359 (83.3) | 1226 (74.8) | 4049 (79.5) |
| Yes | 357 (19.6) | 272 (16.7) | 413 (25.2) | 1042 (20.5) |
Baseline/equivalent matched time: end of first pregnancy for exposed and equivalent time on ART for matched nonexposed women. 3TC, lamivudine; ABC, abacavir; ARV, antiretroviral; AZT, zidovudine; d4T, stavudine; EFV, efavirenz; FTC, emtricitabine; LPVr, lopinavir; NGO, nongovernmental organizations; NVP, nevirapine; IQR, interquartile range; TDF, tenofovir; ZDV, zidovudine.