Summary, characteristics of included studies by country income group
| Study | Study design | Specimen collection timing and type | Sample size for outcome of interest; number of adverse outcomes in women with gonorrhoea/total number of women with adverse outcome (%) | NICE checklist criteria fulfilled, internal/external validity* | |||||
| PTB | Sp. ab. | PROM | PM | LBW | ON | ||||
| High-income group | |||||||||
| Agger WA, et al32 | Cohort | First or second trimester; cervical | 676; 0/54 (0) | +/+ | |||||
| Alger LS, et al45 | Case-control | Second or third trimester; cervical | 129; 6/45 (13) | +/+ | |||||
| Amstey MS, Steadman KT41 | Cross-sectional | First or third trimester or intrapartum; cervical | 4444; 56/613 (9) | 5065; 24/620 (4) | 4444; 52/851 (6) | 5065; 15/149 (10) | −/− | ||
| Baer RJ, et al43 | Cross-sectional | Second or third trimester; unclear | 31 720; NR | 31 720; 53/NR | +/++ | ||||
| Burton AE, Thomas S39 | Case-control | First, second or third trimester; urine and vaginal | 760; 18/380 (5) | +/− | |||||
| Charles et al26 | Cohort | NR/unclear; cervical | NR; 10/NR | 2160*; 0/0 (0) | −/− | ||||
| Choi SJ, et al27 | Case-control | NR/unclear; vaginal | 217†; 0/100 (0) | +/+ | |||||
| Edwards LE, et al8 | Case-control | Unclear; NR/unclear | 564; 22/57 (39) | 564; 50/148 (34) | 564; 5/11 (45) | +/+ | |||
| Edwards RK, et al33 | Cohort | NR/unclear; cervical | 134; 0/37 (0) | +/+ | |||||
| Heumann CL, et al40 | Case-control | NR/unclear; NR/unclear | 4095; 93/353 (26) | 4095; 90/416 (22) | 4095; 80/266 (30) | +/++ | |||
| Hill MG, et al29 | Cohort | First, second or third trimester; NR/unclear | 982; 5/171 (1) | 933†; 0/37 (0) | +/++ | ||||
| Johnson HL, et al4 | Case-control | NR/unclear; NR/unclear | 702; 13/135 (10) | 679; 8/112 (7) | ++/++ | ||||
| Kataoka S, et al34 | Cohort | First trimester; vaginal | 877; 0/15 (0) | 877; 0/5 (0) | 877; 0/7 (0) | 877; 0/1 (0) | +/− | ||
| Mann JR, et al 28 | Cross-sectional | Unclear; NR/unclear | 7931†; 749/7931 (9) | +/− | |||||
| Maxwell GL, Watson WJ30 | Case-control | Second or third trimester; cervical | NR; 11/182 (6) | 182; 1/8 (13) | −/− | ||||
| Stoll BJ, et al37 | Cohort | First, second or third trimester; cervical | 11 018; 30/837 (4) | 11 018; 14/319 (4) | 11 018; 71/1754 (4) | +/− | |||
| Upper middle-income group | |||||||||
| Adachi K, et al7 | Cohort | Intrapartum or post partum; urine | 1373; 13/148 (9) | 1373; 4/41 (10) | 1373; 21/244 (9) | 1373; 0/2 (0) | ++/++ | ||
| Donders GG, et al5 | Cohort | NR/unclear; cervical | 167; 5/29 (17) | −/− | |||||
| Hitti J, et al38 | Case-control | Post partum; cervical | 1328; 1/661 (<1) | ++/+ | |||||
| Moodley D, et al35 | Cohort | First, second and third trimester and post partum; NR/unclear | 568; 13/157 (8) | 608; 9/77 (12) | 550; 3/54 (6) | ++/+ | |||
| Nasution TA, et al31 | Cross-sectional | Intrapartum or post partum; vaginal, placental swab or blood | 60†; 0/30 (0) | 80; 0/40 (0) | −/− | ||||
| Pourabbas B, et al50 | Cross-sectional | Third trimester; cervical | 239; 1/29 (3) | +/− | |||||
| Lower middle-income group | |||||||||
| Elliott B, et al6 | Case-control | Post partum; cervical | 319; 18/160 (11) | 154; 4/46 (9) | 319; 18/160 (11) | ++/+ | |||
| Galega FP, et al51 | Cross-sectional | Intrapartum; vaginal | 296; 12/12 (100) | +/− | |||||
| Gichangi PB, et al49 | Cohort | Post partum; cervical | 203; 11/51 (22) | +/+ | |||||
| Gichuhi S, et al52 | Case-control | Third trimester; cervical | 445; 1/99 (1) | +/+ | |||||
| Laga M, et al9 | Cohort | Post partum; cervical | 781; 28/181 (15) | +/− | |||||
| Mason PR, et al46 | Cross-sectional | Intrapartum; cervical | 105; 4/24 (17) | +/+ | |||||
| Warr AJ, et al47 | Cohort | Second and third trimester and post partum; vaginal | 1221; 1/19 (5) | ++/+ | |||||
| Schwab FD, et al36 | Cohort | Second trimester; vaginal swab | 62; 0/23 (0) | −/− | |||||
| Temmerman M, et al44 | Case-control | First, second or third trimester; cervical | 387; 10/193 (5) | +/+ | |||||
| Low-income group | |||||||||
| Christian P, et al42 | Cross-sectional | Post partum; urine | 607–707; NR | 607–707; NR | 607–707; NR | −/− | |||
| Kupka R, et al48 | Cohort | First, second and third trimester; cervical or vaginal | 946; 1/21 (5) | +/+ | |||||
*++, all or most checklist criteria fulfilled; +, some of checklist criteria fulfilled; −, few or no checklist criteria fulfilled.
†Study not included in meta-analysis.
LBW, low birth weight; NICE, National Institute of Health and Care Excellence; NR, not reported; ON, ophthalmia neonatorum; PM, perinatal mortality; PROM, premature rupture of membranes; PTB, preterm birth; Sp. ab., spontaneous abortion.