PLOD1 and polycystic ovary syndrome: Three studies indicated that the change in the LH/FSH ratio over time was similar in both women with PCOS and without PCOS (Carmina et al., 2012a,b; Udesen et al., 2019), although one study demonstrated a significant decrease in the median LH/FSH ratio per year in women with PCOS, but not in controls (Brown et al., 2011).