Down syndrome (DS) is a common genetic disorder and is associated with an increased likelihood of many diseases, including defects of the heart, genitourinary system, gastrointestinal tract, and oncological diseases. The aim of this study was to analyze medical problems occurring in newborns with DS and to create a basic diagnostic and therapeutic algorithm intended primarily for neonatologists, pediatricians, family physicians, and physicians of other specialties caring for children with DS. Over a 5-year period, the medical records of 161 neonates with Down syndrome from four neonatology departments in Poznan, Poland, were examined. After applying exclusion criteria, 111 patients were analyzed. Data obtained from medical history included sex, week of gestation, birth weight, APGAR score, clinical symptoms, peripheral blood count with smear, and clinical features such as jaundice, hemorrhagic diathesis, ascites, hepato- or splenomegaly, pericardial or pleural effusion, respiratory failure, and other rare transient signs of abnormal myelopoiesis: fetal edema, hepatic fibrosis, renal failure, and rush. In the study group, 8% of children with Down syndrome were diagnosed with a heart and 1.8% with a genitourinary defect. Transient abnormal myelopoiesis syndrome (Transient abnormal myelopoiesis (TAM)) was found in 10% of newborns with DS. A blood count with blood smear, cardiology consultation with echocardiography, and an abdominal ultrasound should be performed in the first few days after birth in all newborns with Down syndrome. If this is not possible and the childâs condition is stable, these tests can be performed within 2â3 months after birth.