Saturation screening of congenital heart defects in the newborn takes place in Finnish maternity hospitals. Saturation screening has been shown to be a cost-effective way to screen critical heart defects in the newborn. Screening aims to reveal the heart defect before potential circulatory collapse. Early diagnosis is important, as invasive therapeutic measures for congenital heart defects have been concentrated to one center. There are differences in the implementation of saturation screening. We therefore recommend unifying the screening system to conform with the recently published Nordic recommendation. Screening should be conducted during the first day of life by measuring the saturation values of both the right upper limb and one of the lower limbs.