Women self-reporting PCOS symptoms should not be overlooked

Sir, We have read with great interest the article ‘Where are we in understanding the natural history of polycystic ovary syndrome? A systematic review of longitudinal cohort studies’, recently published in Human Reproduction (Kiconco et al., 2022). The article aims to describe the natural history of reproductive, psychological and oncological features in women with polycystic ovary syndrome (PCOS) in comparison to those without PCOS, across the life course. The review included 21 longitudinal studies, whereas 216 studies were excluded at the full-text review stage due to various reasons, such as unclear criteria or self-reported PCOS status. The authors found that overall, existing longitudinal data were inconsistent and conflicting but suggested that total testosterone and dehydroepiandrosterone sulfate levels decline to a greater degree in women with PCOS compared to those without PCOS, and that the risk for gestational diabetes is higher in women with PCOS than in those without PCOS. The definition of inclusion and exclusion criteria prior to the literature search and review process is a critical point in determining the outcome and, especially, the generalizability of the findings of a systematic review. In Kiconco et al. (2022), subjects were included if they had been diagnosed with Rotterdam or NIH-based criteria according to recent recommendation (Al Wattar et al., 2020). Due to the strict implementation of these criteria, the largest and longest prospective population-based cohort examining the wide spectrum of health-related issues of women with PCOS was not included in the systematic review. We feel obliged to raise this unique cohort study to the awareness of the readers of Human Reproduction, given that population-based birth cohorts, if sizable enough, are the best way to investigate the so-called ‘natural history’ (i.e. considering the genetic and environmental determinants as well as the changing features) of any multifactorial disease or syndrome, such as PCOS, during life.