Table 1.
Univariable and multivariable analyses of the association between timing of ART and detectable maternal viral load at delivery among second pregnancies to diagnosed HIV-positive women.
| Detectable/total (%) | Univariable analyses | Multivariable analysis (n = 1590) | |||||
| OR | 95% CI | P-value | aOR | 95% CI | P-value | ||
| Timing of ART | |||||||
| After conception | 220/840 (26.2) | 5.31 | (3.86–7.30) | 4.34 | (3.03–6.20) | ||
| Prior to conception | 53/846 (6.3) | 1 | <0.001 | 1 | <0.001 | ||
| Maternal age group (years) | |||||||
| <25 | 33/184 (17.9) | 1 | 0.046 | ||||
| 25–34 | 183/1049 (17.4) | 0.97 | (0.64–1.46) | ||||
| ≥35 | 57/452 (12.6) | 0.66 | (0.41–1.05) | ||||
| Maternal region of origin | |||||||
| UK/Ireland | 30/234 (12.8) | 1 | 0.288 | ||||
| Sub-Saharan Africa | 218/1317 (16.6) | 1.35 | (0.90–2.03) | ||||
| Elsewhere | 24/134 (17.9) | 1.48 | (0.83–2.66) | ||||
| Maternal HIV risk factor | |||||||
| Othera | 260/1612 (16.1) | 1 | 0.499 | ||||
| Injecting drug use | 7/34 (20.6) | 1.35 | (0.58–3.13) | ||||
| Time period | |||||||
| 2000–2002 | 12/47 (25.5) | 2.34 | (1.16–4.70) | <0.001 | 3.32 | (1.38–8.00) | |
| 2003–2005 | 76/338 (22.5) | 1.98 | (1.39–2.81) | 1.90 | (1.24–2.90) | ||
| 2006–2008 | 110/715 (15.4) | 1.24 | (0.90–1.70) | 1.05 | (0.74–1.49) | ||
| 2009–2010 | 75/586 (12.8) | 1 | 1 | 0.002 | |||
| Reporting region | |||||||
| London | 141/830 (17.0) | 1 | 0.001 | 1 | <0.001 | ||
| Elsewhere in England | 116/647 (17.9) | 1.07 | (0.81–1.40) | 1.34 | (0.98–1.83) | ||
| Wales/Scotland/N Ireland | 3/63 (4.8) | 0.24 | (0.08–0.79) | 0.31 | (0.09–1.06) | ||
| Ireland | 13/145 (9.0) | 0.48 | (0.26–0.88) | 0.42 | (0.22–0.80) | ||
| Type of antenatal ART | |||||||
| Mono/dual | 33/71 (46.5) | 3.96 | (2.42–6.50) | <0.001 | 2.89 | (1.65–5.06) | |
| HAART – PI-based | 177/985 (18.0) | 1 | 1 | <0.001 | |||
| HAART – NNRTI-based | 45/536 (8.4) | 0.41 | (0.29–0.58) | 0.48 | (0.32–0.74) | ||
| HAART – otherb | 18/94 (19.1) | 1.13 | (0.66–1.91) | 1.16 | (0.62–2.18) | ||
| Earliest CD4+ cell countc (cells/μl) | |||||||
| ≥500 | 60/534 (11.2) | 1 | <0.001 | 1 | <0.001 | ||
| 350–499 | 82/486 (16.9) | 1.60 | (1.12–2.29) | 1.94 | (1.31–2.87) | ||
| 200–349 | 77/442 (17.4) | 1.67 | (1.16–2.40) | 2.00 | (1.34–2.97) | ||
| <200 | 38/128 (29.7) | 3.34 | (2.10–5.31) | 4.50 | (2.69–7.51) | ||
aOR, adjusted odds ratio; ART, antiretroviral therapy; CI, confidence interval; HAART, highly active antiretroviral therapy; NNRTI, non-nucleoside reverse-transcriptase inhibitor; NRTI, nucleoside reverse-transcriptase inhibitor; OR, odds ratio; PI, protease inhibitor.
aIncludes heterosexual transmission, originating from a high HIV prevalence area, and vertical transmission.
bIncludes those receiving NNRTIs and PIs, and those receiving NRTIs only – groups combined due to small numbers.
cEarliest measurement in women's second reported pregnancy, not restricted to measurements taken prior to ART initiation.