Alexa von Winterfeld, M.D.

Has worked as a pediatrician since 1996
Mother of one child

2012 Joined the group practice
Since 2010 Board-certified specialist in Pediatrics
Since 2005 Practicing pediatrician
1999–2002 Physician at the German Heart Center Berlin and at Charité, Department of Pediatric Cardiology
1998–1999: Physician in the “Pediatric Cardiology” and “Pediatric Oncology” departments at the Wandlitz Rehabilitation Clinic
1998: Ph.D.
1996–1998: Physician in the Department of Pediatrics at Suhl Hospital.

Christian-Olaf Bader, M.D.

, a medical specialist, grew up in Brussels, Belgium.
has one child.

Education:
Subspecialty in Pediatric Cardiology (2016) | Board-certified in Pediatrics (2011)
Specialty training and subspecialty certification in pediatric cardiology at the Department of Pediatrics, Charité, Berlin (2007–2015)
DFG Return Fellowship on HP1 and epigenetic regulation under Dr. Prim B. Singh, Research Center Borstel (2007)
DFG Research Fellowship at the Cutaneous Biology Research Center, Massachusetts General Hospital (MGH), Harvard Medical School, Boston, USA, and the Swiss Federal Institute of Technology (ETH), Zurich, Switzerland, on the ontogenesis of the lymphatic endothelium under Prof. Dr. Detmar (2004–2006)
Residency training at the Department of Pediatrics, University of Göttingen (2002–2004) 
Intern in hematology, oncology, and internal medicine under Prof. Dr. Hossfeld at the University Medical Center Eppendorf (UKE), Hamburg (2001–2002)
Ph.D. in neurobiology at the ZMNH under Prof. Dr. Schaller at the University Medical Center Eppendorf (UKE), Hamburg (1997–2003)
Studied medicine at the University of Hamburg, including a clinical rotation at the Altona Children’s Hospital, Mount Sinai in New York, Hôpital Cochin in Paris, and the Cliniques Universitaires St-Luc in Brussels (1996 to 2000)
Studied medicine at the University of Cologne (1993 to 1996)
Studied chemistry, earning an intermediate degree at the University of Cologne (1991 to 1994)
Earned a high school diploma at the German School in Brussels (1991)

Work in pediatric and adolescent medicine practices: 

Since July 1, 2017, I have been a pediatrician in private practice in a joint practice with Dr. von Winterfeld at the Pediatric Practice at Theodor-Heuss-Platz in Berlin (succeeding Adnan Al-Radhi) 
Pediatric practice at the MVZ Uhlandstraße, Berlin (2017) | Pediatric practice at the AGZ of the Charité, Berlin (2016) | Pediatric practice at Hubermann and Colleagues, Prenzlauer Berg, Berlin (2014–2016) and locum tenens positions in Berlin, Hamburg, and Schleswig-Holstein

Lennart Wallraff, M.D.

Pediatrics ist and Specialist in Anesthesiology and Critical Care Medicine

Since 2025, a board-certified specialist at “Kinderarztpraxis am Theo”

2023–2025: Resident at the Department of Pediatrics, Evangelisches Waldkrankenhaus and Martin-Luther-Krankenhaus, Berlin

2019–2022: Resident at “Kinderarztpraxis am Theo”

2018–2019: Resident at the Department of Pediatrics, Vivantes Hospital in Friedrichshain, Berlin

2013–2017: Board certification exam in anesthesiology; resident at the Department of Anesthesiology, Surgical Intensive Care, and Pain Management at the Evangelical Hospital in Düsseldorf

2015: Specialized Training in Emergency Medical Services and Emergency Medicine at the

Düsseldorf Professional Fire Department

2011–2012: Resident in the Department of Pediatric Surgery, Wilhelmstift Catholic Children's Hospital, Hamburg

2009–2010: Clinical rotation at the Department of Trauma Surgery and Orthopedics and the Department of Visceral Surgery, Leipzig University Hospital; Department of Pediatrics, Leipzig University Hospital; Hôpital Albert Schweitzer, Lambaréné, Gabon

Education

2003–2010: Studied medicine at the University of Leipzig

1987–2001 Waldgrund- und Oberschule, Berlin

Doctoral Dissertation

“Clinical and Radiological Outcomes of Angle-Stable Osteosynthesis Techniques for Distal Humerus Fractures, with Special Emphasis on Complications,” supervised by Prof. Dr. Christoph Josten and Dr. Ludwig Schütz; University Hospital of Leipzig

Ms. Sinah Hanser

Resident in Specialized Medical Training Pediatrics

Since April 2026: Pediatric and Adolescent Medical Practice at Theo

2025–2026: Maternity Leave, Parental Leave

2024–2025: Resident; Department of Pediatrics, Havellandklinken

2022–2023: Resident, Department of Neonatology, Bülach Hospital; Canton of Zurich (CH)

2018–2024: Ph.D. at Vivantes Klinikum am Urban, Department of Psychiatry, Psychotherapy, and Psychosomatics: “Interdisciplinary Collaboration to Improve Care for Young People in Mental Health Crises: An Evaluation of the Utilization of the New ‘soulspace’ Outreach and Counseling Service in Berlin-Kreuzberg”

June 2021: Licensed as a physician

Studied medicine at Charité, University Medical Center Berlin

Ms. Lisa Pfau

Resident in General Practice

2025–2026: Resident in Orthopedics and Trauma Surgery

Dr. Boldt and Hainbach's Practice, Berlin

2025: Resident in psychiatry, psychosomatic medicine, and

Psychotherapy, Vivantes Wenckebach Hospital, Berlin

2024 Resident in Geriatrics and Palliative Care

Helios Emil von Behring Hospital, Berlin

Since 2019: Ph.D. thesis titled “Determinants, Enabling Factors, and Barriers to Successful Digital Layoff Management”

Institute of General Medicine, Lübeck; supervised by Prof. Steinhäuser

2023: Licensed as a physician

2016–2023: Studied medicine at the University of Lübeck