It has also been demonstrated that PROK1 is upregulated in the myometrium and the placenta during labour, suggesting a role for PROK1 in the induction of term and preterm labour.15 16 However, in this study, s-PROK1 did not predict late miscarriages/preterm deliveries in pregnant women with PCOS, but we cannot exclude that a limited number of cases might have influenced our results. This evidence concerns the gene PROK1 and polycystic ovary syndrome.