Our Physicians


Please welcome Joanna Graeber, DO to our practice. Joanna joined our practice on August 6, 2018. We are pleased to have her join our team.


​A. Radford MacFarlane, MD
Dr. MacFarlane graduated from Jefferson Medical College in 1982 and completed his pediatric residency at Dartmouth Hitchcock Medical Center, NH in 1985.  He became the medical director of Toledo Family Health Center, Ohio, while in the National Health Service Corps from 1985 through 1990. In 1991, Dr. MacFarlane became a staff pediatrician at St. Francis Pediatric Center Wilmington, DE and founded Millcreek Pediatrics in 1999. He was board certified in 1987. 
Dr. MacFarlane has two adult children who have recently graduated from college and he is awaiting becoming a grandparent!
Dr. MacFarlane has a life long interest in personal fitness and activity. He enjoys hiking and, at least yearly, has climbed the highest mountains in Colorado and Scotland.  A naturalist, Dr. MacFarlane is interested in birds, wildlife and alpine plants.


Jenna Seiff, MD 
Dr. Seiff attended medical school in her home state of New Jersey at UMDNJ, New Jersey medical school and graduated in 2002. Dr. Seiff completed her pediatric residency at Mount Sinai Medical Center, NYC and became board certified in 2005. Dr. Seiff worked in NYC for one year and then, with her husband, moved to San Francisco where she joined a private practice in the East Bay. Upon her husband’s completion of a facial plastic surgery fellowship, they relocated to Delaware in 2008. Both she and her husband initially worked in the downstate area and she later joined Mill Creek Pediatrics in May 2012. 
Dr Seiff, her husband and children are happy to call Wilmington their home. Together they enjoy outdoor activities, beach going and traveling. 
Dr Seiff speaks fluent Spanish.


Joanna Graeber, DO

Joanna joined our group in August of 2018.


Meet Our Pediatric Team