Dr. Shields is an OB/GYN nurse practitioner with a doctoral degree in Public Health. As a clinician she provided inpatient and ambulatory care in obstetrics and gynecology. As an epidemiologist she was responsible for the development and operation of the Pregnancy Registry Program at Merck, one of the earliest and most comprehensive pregnancy registry programs within the pharmaceutical industry. As a researcher/writer, she has published scientific papers in Obstetrics & Gynecology, Pediatrics, Birth Defects Research and other medical journals. Dr. Shields is most widely known for her research into medication safety during pregnancy.