A 2-day-old newborn male develops mild cyanosis. An ultrasound examination reveals a patent ductus arteriosus. Which of the following infections will most likely lead to this congenital anomaly?: (A) Toxoplasmosis, (B) Rubella, (C) Cytomegalovirus, (D) Varicella virus
Answer is B. Congenital heart defects are common problems that can be caused by teratogens, such as the rubella virus, or single-gene factors or chromosomal abnormalities.