PMC

Relative frequency with which women rejected sex with their partner, or undertook compliant sex with him, in still-partnered women who met their partner while either using OC (grey bars, n = 461) or not (white bars, n = 749). Data are estimated as marginal means (± s.e.m), adjusted for SOI-R score, general relationship satisfaction and current hormonal condition. Both interactions are statistically significant (sexual rejection: p = 0.005; compliant sex: p = 0.014). Short and long refer to current relationship duration, split by the median relationship length of 142 months.

Measures of relationship satisfaction in women who met their partner while either using (grey bars) or not using (white bars) oral contraceptives (OCs). Data show estimated marginal means of standardized scores (± s.e.m), adjusted for SOI-R score, relationship duration and current hormonal condition. Estimates of sexual satisfaction and partner attractiveness also control for general (non-sexual) relationship satisfaction. (a) Women still in a relationship with the biological father of their first child (749 were non-users and 462 were OC users at time of meeting). (b) Retrospective scores of women no longer in a relationship with the father of their first child (492 were non-users and 236 were OC users at time when couples met). Significant differences are indicated by *p < 0.05 and **p < 0.01.

Effects of OC use at the time of partner choice on relationship outcome. (a) Frequency of separation is lower among women using OC when they met the biological father of their first child, compared with those who were not (p < 0.0001). (b) Relationship duration is longer (p = 0.001) among women who were using OCs when couples met (analysis includes only separated couples). Horizontal lines are median number of months, boxes indicate inter-quartile range. Circles and triangles represent outliers and extreme values, respectively. Both analyses control for women's age and SOI-R score. The difference in (b) was robust to exclusion of outliers (open circles) and extreme values (open triangles; p < 0.001). (a) Black bars, observed; white bars, expected.