INTRODUCTION Retrospective studies have reported an association between a single episode of significantly increased fetal movements (IFMs) and stillbirth after 28 weeks' gestation. This prospective study aimed to report the outcome of pregnancies associated with maternal perception of IFMs and determine whether this symptom is associated with adverse pregnancy outcome, a pathological intrauterine environment or placental dysfunction. MATERIAL AND METHODS Women reporting IFMs after 28 weeks' gestation were recruited from St Mary's Hospital, Manchester and Liverpool Women's Hospital, UK, between 1 November 2017 and 1 May 2019. Demographic and clinical information were obtained and an ultrasound scan was performed to assess fetal biometry, liquor volume and umbilical artery Doppler. Maternal serum samples were collected for analysis of placentally derived biomarkers using ELISA. After delivery, maternal and fetal outcome data were collected and placentas and umbilical cord blood were obtained for analysis using immunohistochemistry and ELISA, respectively. Placental and serum samples were matched by gestation and maternal characteristics to participants with normal fetal activity. RESULTS Seventy-seven women presented with IFM, representing 0.45% of the maternity population; 64 women consented to participate in the study, of which 7 (10.9%) experienced adverse pregnancy outcome: birthweight