Physical stress has been implicated in influencing female fertility. Women who had a job & worked more than 32 hours per week experienced a longer time to conception compared to women who worked 16 to 32 hours per week.

Psychological stress, such as anxiety disorder or depression, affects 30% of women who attend infertility clinics, possible due in part to infertility diagnosis and treatments.

Receiving instruction on how to deal effectively with stress, or merely receiving support, made a significant difference for women undergoing fetility treatment. There was a higher conception rate for women who were part of a cognitive behavioural intervention group (55%) or a support group (54%) than for those women not receiving any intervention (20%). Women who receive support and counselling may reduce their anxiety and depression levels, and increase their chances of becoming pregnant. Positive moods correlated with increased chances of delivering a live baby. Fertilization of oocytes also decreased when stress increased. A probable explanation for these associations may lie in stress hormone levels.

Males who experienced more than two stressful life events before undergoing fertility treatment were more likely to be classified below WHO standards for sperm concentration, motility & morphology.

In a study including 950 men conducted by Gollenberg et al., stress such as a job, life events & even societal strain were seen to have a significant impact on sperm density, total sperm counts, forward motility & morphology.

Stress & depression are thought to reduce testosterone & luteinizing hormone (LH) pulsing, disrupt gonadal function, and ultimately reduce spermatogenesis and sperm parameters. It has yet to be determined if depression causes low testosterone, or if low testosterone can cause depression. Although there appears to be a relationship between stress & infertility, it is uncertain which is the cause and which is the effect.

Decreased stress levels have been associated with improvements in fertility. In one study, higher ranks in the WHO 5 Well Being Index correlated with higher sperm concentrations for each successive gain in rank, an increase in concentration of 7.3% was observed.