Beckwith-Wiedemann syndrome (BWS) is a model of imprinting disease, caused by mutations or epigenetic events affecting the gene locus p15.1 of chromosome 11. BWS is characterized by abdominal wall defects, macroglossia, organomegaly, abnormal lining on ear lobes, hemihypertrophy, hyperinsulinemiainduced macrosomia and postnatal hypoglycemia, and increased risk of malignancy. Nowadays, the frequency of genetic imprinting diseases has begun to increase, parallel to the increased rate of pregnancies achieved by assisted reproduction techniques.Because of the macrosomia, the risk of preterm labor and prematurity-induced complications is increased. The prognosis is mainly dependent on postnatal hypoglycemia, increased risk of obstruction of macroglossia and increased risk of embryonic tumors. If macroglossia is excessive, it can cause feeding difficulties and respiratory distress. Patient comfort can be achieved by surgical tongue reduction. Here, two macrosomic preterm babies diagnosed with BWS were evaluated in terms of prenatalpostnatal characteristics and surgical tongue reduction operations.

Keywords: Beckwith-Wiedemann syndrome, assisted reproduction, prematurity, macroglossia.