Relationship between hair and salivary cortisol and pregnancy in women undergoing IVF.

Evidence for an association between cortisol and clinical pregnancy in women undergoing In Vitro Fertilisation (IVF) is mixed with previous studies relying exclusively on short term measures of cortisol in blood, saliva, urine, and/or follicular fluid. Hair sampling allows analysis of systemic levels of cortisol over the preceding 3-6 months. The present study sought to explore the relationship between cortisol and clinical pregnancy outcome in women undergoing IVF utilising multiple indices of cortisol derived from both saliva and hair measured prior to commencing gonadotrophin treatment. A total of 135 women (mean age 34.5 SD+/-4.8) were recruited from an English fertility clinic (December 2012-April 2014) 60% of whom became pregnant (n=81). Salivary cortisol data were obtained over two days: upon awakening, 30min post awakening, and at 22:00. A subsample (n=88) of the women providing salivary samples were approached consecutively to provide hair samples for the measurement of cortisol. Independent Logistic regression analyses revealed that salivary cortisol measures including cortisol awakening response (CAR) (p=0.485), area under the curve with respect to ground (AUCg) (p=0.527), area under the curve with respect to increase (AUCi) (p=0.731) and diurnal slope (p=0.889) did not predict clinical pregnancy. In contrast, hair cortisol concentrations significantly predicted clinical pregnancy (p=0.017). Associations between hair cortisol and clinical pregnancy remained when controlling for accumulations of salivary cortisol (p=0.034) accounting for 26.7% of the variance in pregnancy outcome. These findings provide preliminary evidence that longer term systemic cortisol may influence reproductive outcomes; and in turn suggests that interventions to reduce cortisol prior to commencing IVF could improve treatment outcomes.

The association of physiological cortisol and IVF treatment outcomes: a systematic review.

PURPOSE: A systematic review was conducted to (1) collate and synthesise the available evidence for the role of cortisol in relation to IVF treatment outcomes; (2) to establish the strength of an association between cortisol and IVF; and (3) to assess the overall quality of the studies and guide future research in this area. METHODS: Seven electronic databases, including the reference lists of published papers, were searched. Inclusion criteria qualified any prospective/observational cohort study that reported original data. Quality assessment of eligible studies was conducted using the STROBE statement, which was used to assess the risk of bias and the quality of observational studies included in this review. RESULTS: A total of eight studies reported a significant association between cortisol and IVF outcomes. Three studies found that higher cortisol may be associated with more favourable IVF outcomes, whereas five studies found that lower cortisol levels may be conducive to IVF success. Eleven of all studies included in this review were regarded as low quality publications. CONCLUSIONS: Study findings were that the evidence for the role of cortisol in relation to IVF outcomes is currently mixed. Future researchers are encouraged to consider the methodological limitations highlighted in this review and to utilise more robust assessment methods when examining the influence that chronic, rather than acute, stress may have on IVF outcomes.