Table 1.
Frequencies (percentages) of missing data, for participants with outcome data
| Variable | Infected cohort (n=256) | Uninfected comparison cohort (n=1220) | Total (n=1476) |
|---|---|---|---|
| Socioeconomic group: | |||
| Managerial and professional occupations | 50 (20) | 333 (27) | 383 (26) |
| Other employed | 101 (39) | 608 (50) | 709 (48) |
| Unemployed/student | 28 (11) | 156 (13) | 184 (12) |
| Missing | 77 (30) | 123 (10) | 200 (14) |
| Booking body mass index (kg/m2): | |||
| <30 | 178 (70) | 867 (71) | 1045 (71) |
| ≥30 | 63 (25) | 202 (17) | 265 (18) |
| Missing | 15 (6) | 151 (12) | 166 (11) |
| Ethnicity: | |||
| White | 197 (77) | 973 (80) | 1170 (79) |
| Other | 57 (22) | 217 (18) | 274 (19) |
| Missing | 2 (1) | 30 (2) | 32 (2) |
| Smoking status: | |||
| Did not smoke during pregnancy | 195 (76) | 937 (77) | 1132 (77) |
| Smoked during pregnancy | 59 (23) | 257 (21) | 316 (21) |
| Missing | 2 (1) | 26 (2) | 28 (2) |
| Parity: | |||
| Primiparous | 96 (38) | 523 (43) | 619 (42) |
| Multiparous | 158 (62) | 694 (57) | 852 (58) |
| Missing | 2 (1) | 3 (0.3) | 5 (0.3) |
| Age (years): | |||
| <20 | 26 (10) | 61 (5) | 87 (6) |
| 20-34 | 198 (77) | 894 (73) | 1092 (74) |
| ≥35 | 32 (13) | 264 (22) | 296 (20) |
| Missing | 0 (0) | 1 (0.1) | 1 (0.1) |
| Multiple pregnancy: | |||
| No | 251 (98) | 1207 (99) | 1458 (99) |
| Yes | 5 (2) | 13 (1) | 18 (1) |
| Missing | 0 (0) | 0 (0) | 0 (0) |
| Any item of data missing: | |||
| No | 163 (64) | 947 (78) | 1110 (75) |
| Yes | 93 (36) | 273 (22) | 366 (25) |