Trisomy 18, also known as Edward Syndrome, occurs when there is an extra copy of chromosome 18. Trisomy 18 can cause complex medical problems, including defects of the heart, brain, spinal cord, and other internal organs. Cleft lips and palates are also more common in babies with Trisomy 18. They may have hand and foot anomalies. Babies with Trisomy 18 may have difficulty feeding properly and regulating their breathing and temperature.