Dr. Frederick Kohn is an obstetrician-gynecologist in Tarzana, California and is affiliated with multiple hospitals in the area, including Northridge Hospital Medical Center and Providence Tarzana Medical Center. He received his medical degree from The Ohio State University College of Medicine and has been in practice for 27 years.. Obstetricians/gynecologists (OB-GYNs) specialize in the woman's reproductive tract,pregnancy and childbirth.