The participant characteristics and comparison between HIV-positive pregnant women with and without premature birth and mother-to-child HIV transmission events
| Characteristic | Total | Preterm birth | Mother-to-child HIV transmission events | ||||
| N (%) | χ2 | P value | N (%) | χ2 | P value | ||
| Age | 7.091 | 0.131 | 4.974 | 0.290 | |||
| <20 | 57 | 11 (19.30) | 2 (3.51) | ||||
| 20–24 | 252 | 29 (11.51) | 24 (9.52) | ||||
| 25–29 | 331 | 32 (9.67) | 21 (6.34) | ||||
| 30–34 | 261 | 29 (11.11) | 14 (5.36) | ||||
| ≥35 | 172 | 27 (15.70) | 11 (6.40) | ||||
| Nationality | 4.779 | 0.029 | 3.669 | 0.055 | |||
| Han | 953 | 121 (12.70) | 59 (6.19) | ||||
| Others | 120 | 7 (5.83) | 13 (10.83) | ||||
| Education | 3.268 | 0.195 | 12.531 | 0.011 | |||
| Primary school or lower | 217 | 30 (13.82) | 19 (8.76) | ||||
| Junior or senior middle school | 708 | 89 (12.57) | 35 (4.94) | ||||
| College or above | 122 | 9 (7.38) | 14 (11.48) | ||||
| Unknown | 26 | 0 (0.00) | 4 (15.38) | ||||
| Occupation | 0.722 | 0.697 | 0.896 | 0.639 | |||
| Farmer | 606 | 74 (12.21) | 37 (6.11) | ||||
| Housekeeping or unemployment | 324 | 40 (12.35) | 25 (7.72) | ||||
| Others | 143 | 14 (9.79) | 10 (6.99) | ||||
| Marital status | 5.857 | 0.210 | 6.180 | 0.158 | |||
| Single | 50 | 5 (10.00) | 5 (10.00) | ||||
| First married | 745 | 80 (10.74) | 44 (5.91) | ||||
| Remarried | 182 | 28 (15.38) | 13 (7.14) | ||||
| Cohabiting | 81 | 14 (17.28) | 10 (12.35) | ||||
| Divorced/widowed | 15 | 1 (6.67) | 0 (0.00) | ||||
| Gravidity | 1.715 | 0.634 | 4.567 | 0.206 | |||
| 1 | 388 | 40 (10.31) | 34 (8.76) | ||||
| 2 | 326 | 40 (12.27) | 16 (4.91) | ||||
| 3 | 202 | 27 (13.37) | 13 (6.44) | ||||
| >3 | 157 | 21 (13.38) | 9 (5.73) | ||||
| Parity | 4.518 | 0.211 | 14.366 | 0.002 | |||
| 0 | 288 | 34 (11.81) | 32 (11.11) | ||||
| 1 | 456 | 50 (10.96) | 28 (6.14) | ||||
| 2 | 245 | 28 (11.43) | 10 (4.08) | ||||
| >2 | 84 | 16 (19.05) | 2 (2.38) | ||||
| Known HIV infection prior to this pregnant | 3.839 | 0.050 | 8.120 | 0.004 | |||
| No | 305 | 27 (8.85) | 31 (10.16) | ||||
| Yes | 768 | 101 (13.15) | 41 (5.34) | ||||
| Maternal period of HIV detection | 4.032 | 0.402 | 7.307 | 0.121 | |||
| Prepregnancy | 112 | 15 (13.39) | 6 (5.36) | ||||
| Gestation | 345 | 40 (11.59) | 19 (5.51) | ||||
| Intrapartum | 151 | 17 (11.26) | 12 (7.95) | ||||
| Post partum | 63 | 7 (11.11) | 9 (14.29) | ||||
| Unknown | 402 | 49 (12.19) | 26 (6.47) | ||||
| The route of HIV infection | 4.579 | 0.137 | 5.619 | 0.261 | |||
| Sexual transmission | 591 | 72 (12.18) | 39 (6.60) | ||||
| Blood (plasma) collection /transfusion | 129 | 21 (16.28) | 13 (10.08) | ||||
| Mother-to-child transmission | 100 | 14 (14.00) | 4 (4.00) | ||||
| Others | 33 | 1 (3.03) | 4 (12.12) | ||||
| Unknown | 220 | 20 (9.09) | 12 (5.45) | ||||
| Antiretroviral therapy | 0.570 | 0.450 | 1.045 | 0.305 | |||
| No | 98 | 14 (14.29) | 9 (9.18) | ||||
| Yes | 975 | 114 (11.69) | 63 (6.64) | ||||
| Initiation time of antiretroviral therapy | 5.724 | 0.221 | 10.978 | 0.027 | |||
| No antiretroviral therapy | 98 | 14 (14.29) | 9 (9.18) | ||||
| Prepregnancy | 770 | 96 (12.47) | 49 (6.63) | ||||
| Gestation | 79 | 7 (8.86) | 10 (12.66) | ||||
| Intrapartum | 29 | 0 (0.00) | 3 (10.34) | ||||
| Post partum | 94 | 11 (11.70) | 1 (1.06) | ||||
| HIV test results of husbands/sexual partner | 0.074 | 0.786 | 1.221 | 0.543 | |||
| Positive | 366 | 41 (11.20) | 22 (6.01) | ||||
| Negative | 560 | 66 (11.79) | 42 (7.50) | ||||
| Unknown | 147 | 21 (14.29) | 8 (5.44) | ||||
| Moderate–severe anaemia | 0.002 | 0.960 | 0.047 | 1.000 | |||
| Yes | 66 | 8 (12.12) | 4 (6.06) | ||||
| No | 1007 | 120 (11.92) | 68 (6.75) | ||||
| HBV/HCV coinfection | 11.181 | 0.002 | 2.636 | 0.215 | |||
| Yes | 28 | 9 (32.14) | 4 (14.29) | ||||
| No | 1045 | 119 (11.39) | 68 (6.51) | ||||
| Syphilis co-infection | 0.225 | 0.965 | 1.582 | 0.484 | |||
| Yes | 13 | 1 (7.69) | 2 (15.38) | ||||
| No | 1060 | 127 (11.98) | 70 (6.60) | ||||
| Pregnancy-induced hypertension | 0.524 | 0.685 | 0.254 | 0.927 | |||
| Yes | 24 | 4 (16.67) | 1 (4.17) | ||||
| No | 1049 | 124 (11.82) | 71 (6.77) | ||||
| Mode of delivery | 12.174 | 0.002 | 1.096 | 0.578 | |||
| Vaginal delivery | 722 | 72 (9.97) | 45 (6.23) | ||||
| Caesarean delivery | 315 | 54 (17.14) | 25 (7.94) | ||||
| Unknown | 36 | 2 (5.56) | 2 (5.56) | ||||