What is the number of registered obgyn in US where can you see this data?

As of 2021, there were approximately 50,000 practicing obstetricians and gynecologists (OB-GYNs) in the United States. This data can typically be found through professional organizations such as the American College of Obstetricians and Gynecologists (ACOG) or the National Resident Matching Program (NRMP), as well as government health agencies like the Health Resources and Services Administration (HRSA). For the most current statistics, it's advisable to check these sources directly or relevant medical workforce reports.