Factors associated with STI prevalence at first ANC visit in pregnant women in South Africa (2016–2018)
| Any STI, n (%) | No STI, n (%) | OR (95% CI) | aOR (95% CI) | |
| Total | 250 (37) | 419 (63) | ||
| Sociodemographic characteristics | ||||
| Maternal age (years), median (IQR) | 29 (24–33) | 30 (26–34) | 0.95 (0.92 to 0.98) | |
| GA at booking (weeks), median (IQR) | 20 (14–24) | 18 (13–23) | 1.02 (1.00 to 1.05) | 1.03 (1.00 to 1.05)* |
| Education level completed | ||||
| Primary | 106 (42) | 143 (34) | Ref | * |
| Secondary | 132 (53) | 257 (62) | 0.69 (0.50 to 0.96) | 0.76 (0.53 to 1.09) |
| Tertiary (college/university) | 12 (5) | 19 (4) | 0.85 (0.39 to 1.83) | 0.97 (0.44 to 2.10) |
| Relationship with father of child | ||||
| Married/cohabitating | 102 (41) | 231 (55) | Ref | † |
| Not married/non-cohabitating | 133 (53) | 176 (42) | 1.71 (1.23 to 2.36) | 1.53 (1.09 to 2.15) |
| No relationship | 15 (6) | 12 (3) | 1.83 (1.27 to 6.26) | 2.64 (1.18 to 5.87) |
| Employment status | ||||
| Formal employment | 71 (29) | 157 (37) | Ref | * |
| Informal employment | 8 (3) | 12 (3) | 1.47 (0.57 to 3.76) | 1.33 (0.51 to 3.47) |
| Unemployed/attending school | 171 (68) | 250 (60) | 1.51 (1.07 to 2.13) | 1.47 (1.03 to 2.09) |
| Site | ||||
| Cape Town | 78 (31) | 164 (39) | Ref | |
| Tshwane District | 172 (69) | 255 (61) | 1.41 (1.01 to 1.97) | |
| Clinical characteristics in this pregnancy | ||||
| HIV status | ||||
| Negative | 37 (15) | 98 (23) | Ref | ‡ |
| Positive | 213 (85) | 321 (77) | 1.75 (1.16 to 2.66) | 1.86 (1.17 to 2.95) |
| Any STI symptoms | ||||
| No | 190 (76) | 333 (79) | Ref | |
| Yes | 60 (24) | 86 (21) | 1.22 (0.84 to 1.79) | |
| Sexual behaviour during pregnancy | ||||
| Vaginal sex | 220 (88) | 376 (90) | 0.83 (0.51 to 1.37) | |
| Oral sex | 14 (6) | 25 (6) | 0.93 (0.47 to 1.83) | |
| Anal sex | 5 (2) | 11 (3) | 0.75 (0.26 to 2.20) | |
| 2+ sex partners in the past 3 months | 6 (2) | 12 (3) | 0.83 (0.30 to 2.25) | |
| Suspect partner of having another sex partner | ||||
| No | 101 (40) | 201 (48) | Ref | |
| Yes | 94 (38) | 134 (32) | 1.39 (0.97 to 1.99) | |
| Don’t know | 55 (22) | 84 (20) | 1.30 (0.85 to 1.97) | |
| Partner’s serostatus | ||||
| Concordant HIV-negative | 26 (10) | 67 (16) | Ref | § |
| Concordant HIV-positive | 60 (24) | 74 (18) | 2.08 (1.18 to 3.68) | 2.72 (1.50 to 4.93) |
| Serodiscordant | 36 (15) | 64 (15) | 1.44 (0.78 to 2.66) | 1.76 (0.94 to 3.31) |
| Serostatus unknown | 128 (51) | 214 (51) | 1.54 (0.93 to 2.54) | 1.67 (1.00 to 2.82) |
Confidence intervals in bold had sufficient evidence to conclude that the groups were statistically significantly different
*Model adjusted for maternal age, marital status and HIV status.
†Model adjusted for maternal age.
‡Model adjusted for maternal age, marital status, HIV status, employment status and education level.
§Model adjusted for maternal age, marital status, employment status and education level.
ANC, antenatal clinic; aOR, adjusted OR; GA, gestational age; n, number of participants; ref, reference.