Whilst it is accepted that psychological stress can inhibit aspects of reproductive function, including conception rates via coitus, it remains unclear whether stress impacts conception rates via in vitro fertilisation treatment. In humans stress impacts multiple emotional systems. Efforts to understand the psychophysiological effects of stress have traditionally focused on negative emotional states and neglected positive ones. However, individual differences in positive affect influence stress response and recovery. This study explored how several measures of stress and emotion predicted conception rates in 212 female IVF patients and 158 male partners.
Binary logistic regression analyses revealed both male and female depression (but not anxiety or stress) predicted reduced clinical pregnancy rates. The effects of positive emotion however were dependent on gender. Active positive emotions (in females but not males) predicted increased pregnancy odds. Relaxed positive emotion (in males but not females) predicted reduced pregnancy rates.
These results suggest the valence of emotions might not relate to IVF outcomes as strongly as arousal does. High arousal positive emotions predicted increased pregnancy odds whilst low arousal positive and negative states predicted decreased odds. As stress can involve high and/or low arousal states, these results may help explain the current contradictory findings that characterise stress and IVF success rate research to date. However, it may also be that male testosterone is negatively correlated with relaxed positive emotions, and this relationship drives apparent effects of relaxed positive affect on conception.
This is the first study to explore the effect of different types of positive affect on IVF conceptions rates, and one of few to explore positive affect at all in this context. Given the results we argue that more extensive research of this nature is warranted, both for understanding how psychological stress impacts physical outcomes, and for improving IVF patient care delivery.