Meet the Downtown Chicago Maternal–Fetal Medicine Team

Our team at Northwestern Medicine includes highly skilled maternal–fetal specialists committed to providing outstanding, comprehensive care for high-risk mothers and their babies.


Our physicians are all full-time teaching faculty of Northwestern University Feinberg School of Medicine and are board-certified specialists in Obstetrics and Gynecology and Maternal–Fetal Medicine.


Fellows are physicians who have completed their training in Obstetrics and Gynecology and are now obtaining additional specialized training in Maternal–Fetal Medicine.

  • Saba Berhie, MD
  • Ashish Premkumar, MD

Advanced Practice Nurse

Charlotte M. Niznik is an advanced practice registered nurse who has worked in the Department of Obstetrics and Gynecology at Northwestern Medicine since 1990. She is certified in diabetes education and specializes in diabetes and pregnancy management.


  • Mary Ciszewski, RNC
  • Elvia Heredia, RNC
  • Linda Jagielski, LPN
  • Karyn Lasin, BSN, RN

Support Staff

  • Elizabeth Blach (Medical Assistant)
  • Maribel Flores (Patient Procedure Scheduler)
  • Darlene Smith (New Patient Liaison)
  • Linda Hernandez (Patient Service Representative)
  • Maria Fonseca (Patient Service Representative)