Impact of a diagnosis of polycystic ovary syndrome on diet, physical activity and contraceptive use in young women: findings from the Australian Longitudinal Study of Women's Health

STUDY QUESTION: Do diet, physical activity and contraceptive use change after receiving a diagnosis of polycystic ovary syndrome (PCOS)? SUMMARY ANSWER: Using longitudinal data 12 months apart, young women newly diagnosed with PCOS were more likely to stop using contraception but did not change their physical activity or vegetable intake. WHAT IS KNOWN ALREADY: Diagnostic criteria for PCOS have widened to capture more women, despite limited evidence of the benefits and harms. Possible benefits of a PCOS diagnosis are that it may help women with family planning and motivate them to implement healthy lifestyle changes to reduce the reproductive, metabolic and cardiovascular risks associated with PCOS. However, there are no empirical studies investigating how women respond to a diagnosis of PCOS with respect to their health behaviour, and longitudinal population-based studies are lacking. STUDY DESIGN, SIZE, DURATION: This is a longitudinal analysis of two waves of data collected 12 months apart from the cohort born 1989-1995 in the Australian Longitudinal Survey on Women's Health, a population-based cohort study. Women in this cohort were first surveyed in 2012-2013, aged 18-23 years. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women who responded to the 2014 survey (aged 19-24, n = I 1344) and 2015 survey (aged 20-25, n = 8961) were included. Using logistic regression, multinomial logistic regression and linear regression, change in vegetable intake, physical activity and contraceptive use were compared for women newly diagnosed with PCOS to women not reporting a diagnosis of PCOS. Changes in psychological distress and BMI were also examined. MAIN RESULTS AND THE ROLE OF CHANCE: Young women reporting a new diagnosis of PCOS were no more likely to increase their vegetable intake or physical activity than women not reporting a PCOS diagnosis. Women newly diagnosed with PCOS were 3.4 times more likely to stop using contraception during the I2-month study period than women without PCOS (14% versus 4%, 95% CI = 2.3 to 5.1, P < 0.001). This difference remained significant after controlling for demographics, chronic conditions associated with PCOS, endometriosis, BMI and psychological distress (P < 0.001). LIMITATIONS, REASONS FOR CAUTION: All data was self-reported including PCOS diagnosis, assessment of diet quality was limited to vegetable intake only. The exact timing of diagnosis within the 12-month period and whether the women intended to conceive are unknown. The number of women reporting a new diagnosis of PCOS was also relatively small. WIDER IMPLICATIONS OF THE FINDINGS: These findings suggest that a diagnosis of PCOS may not produce short-term benefits by way of improving health behaviour. The observed reduction in contraception use suggests some women may be at increased risk of unplanned pregnancies, highlighting the importance of counselling about contraceptive needs. Both potential benefits and harms must be considered when determining the appropriateness of a PCOS diagnosis.