Pregnancy is known as a period associated with important physiological and psychological changes in women's lives. There is moderately sufficient evidence in the literature to recommend supplementing prenatal physical activity for maternal health benefits. It has been reported that physical exercise by pregnant women in the absence of obstetric contraindications will not pose a risk to the health of the mother and fetus. In the literature, there are no studies examining the effects of reformer pilates on pain, functional capacity, lumbopelvic stabilization, diastasis recti abdominis, abdominal muscle thickness, respiratory functions, pelvic floor dysfunction, urinary incontinence, sexual function, and venous insufficiency in pregnant women. Therefore, this study aimed to investigate the effects of reformer pilates on pain, functional capacity, lumbopelvic stabilization, diastasis recti abdominis, abdominal muscle thickness, respiratory functions, pelvic floor dysfunction, urinary incontinence, sexual function, and venous insufficiency in pregnant women.