Parental occupation¶ | | | | | | |
Professional | Reference | | | | | |
Semiskilled | 3.6 (1.0 to 12.8) | 0.8 (0.2 to 2.5) | 1.9 (0.7 to 5.2) | 1.7 (0.8 to 3.5) | | |
Unskilled/unemployed | 4.9 (1.6 to 14.8) | 1.4 (0.5 to 3.7) | 1.5 (0.6 to 3.7) | 2.1 (1.2 to 4.0) | 0.043 | 0.20 |
Ever smoked¶ | 1.2 (0.4 to 3.6) | 0.1 (0.0 to 0.9) | 2.5 (0.8 to 8.0) | 1.0 (0.5 to 2.0) | 0.97 | 0.006 |
Frequency of sex** ¶ | 1.0 (0.6 to 1.7) | 1.3 (0.7 to 2.4) | 2.0 (1.1 to 3.4) | 1.4 (1.0 to 2.0) | 0.065 | 0.18 |
New partner after drugs/alcohol¶ | 1.9 (0.8 to 4.3) | 3.4 (1.4 to 8.5) | 1.3 (0.6 to 2.7) | 2.0 (1.2 to 3.4) | 0.009 | 0.20 |
New partner in last 3 months¶ | 0.3 (0.1 to 0.9) | 2.2 (0.8 to 6.4) | 1.3 (0.6 to 2.9) | 1.0 (0.6 to 1.8) | 0.98 | 0.013 |
Practised sex during period¶ | 0.9 (0.4 to 2.1) | 0.6 (0.2 to 1.5) | 3.3 (1.5 to 7.2) | 1.3 (0.8 to 2.3) | 0.30 | 0.008 |
Cleansed vagina after sex¶ | 2.2 (0.9 to 5.3) | 2.2 (0.7 to 6.4) | 2.5 (1.1 to 5.9) | 2.3 (1.4 to 3.9) | 0.002 | 0.96 |
Condom at last sex¶ | 0.3 (0.1 to 0.9) | 1.0 (0.4 to 2.3) | 0.8 (0.4 to 1.7) | 0.6 (0.4 to 1.1) | 0.089 | 0.20 |
Gynaecological age** | 0.7 (0.5 to 0.9) | 0.8 (0.6 to 1.0) | 0.8 (0.6 to 1.0) | 0.7 (0.6 to 0.9) | 0.001 | 0.50 |
Emergency contraception (last 12 months) | 2.5 (1.1 to 5.9) | 0.7 (0.3 to 1.7) | 0.9 (0.4 to 1.8) | 1.2 (0.7 to 2.0) | 0.54 | 0.054 |
Breast stage (Tanner)** | 0.6 (0.3 to 1.1) | 0.6 (0.3 to 1.2) | 0.6 (0.4 to 1.1) | 0.6 (0.4 to 0.9) | 0.082 | 0.98 |
Ectopy present | 1.7 (0.7 to 3.7) | 0.8 (0.3 to 2.0) | 2.2 (1.0 to 4.7) | 1.6 (0.9 to 2.7) | 0.086 | 0.22 |
Cycle regularity (days) | | | | |
21–42 | Reference | | | | | |
<20 | 2.2 (0.7 to 7.0) | 0.9 (0.2 to 3.6) | 2.0 (0.6 to 6.2) | 2.0 (0.6 to 6.2) | | |
>42 (oligomenorrhoea) | NA | 0.3 (0.1 to 1.8) | 0.3 (0.0 to 2.6) | 0.3 (0.0 to 2.6) | 0.027 | 0.21 |
“irregular” | 0.7 (0.2 to 2.3) | 3.5 (0.7 to 17.8) | 0.5 (0.2 to 1.6) | 1.4 (0.6 to 3.0) | | |