I am a CA-3 DO at an allo institution applying for pain fellowship.
I only took the USMLE Step 1 to increase the odds of matching in Anesthesiology. As a side note, I heard that someone high up mentioned the only DOs they interview are ones who at least have a USMLE score (step 1) in my program.
Back to fellowship. If you look on gaswork.com you may notice that there are pediatric anesthesiology fellowships advertised as job listings. Some of these are at notable institutions, eg UT Southwestern in Dallas, Texas. You can actually search the job listings *by fellowship* to get a national listing of available fellowships. You may have to look to see how old these listings are, and you are just now a pgy-1, so this will informational only to you at this time. Seems to me like they have little to no competition, actually looking for applicants. I am sure at CHOP and other places there would be some competition.
Peds fellowship is generally not too sought after. Common reasons I have heard is no one wants to treat all the sick kiddos all the time. Peds on the other hand trends toward academic practice as ell. Healthy peds you can do as a generalist anesthesiologist.
Critical care is being promoted by the ASA but even the academic guys complain that there is no financial incentive. Not competitive at this time.
Pain very competitive in the sense that it is en vougue. Potential for better hours, pay, etc. Downside is patient population, narc writing, and decreasing reimbursements every year. Lots of cool procedures. Lots of epidurals. Few true emergencies, etc.
OB-few fellowships. Fairly non competitive. I have heard that in a few select areas of the country, Los Angeles, for example, that there are a few boutique practices that won't even interview you unless you are fellowship trained. Generally, not very many general anesthesiologists desire to actually work in the OB departments in private practice, and hence if you like it, the thought is, why not get paid full pay while doing it full-time in private practice. Again, if you go interview somewhere and tell them you want OB work, its yours.
Regional fellowship-another non boarded fellowship at this time, with little to gain except some volume in blocks that you can do in an outpatient ortho specialty hospital and get paid full fledged for it. I have an attending who tells me he placed 1800 blocks in a similar setting last year and made bank at the same time. The rumor has it that these non-boarded fellowships are basically private practice groups who are looking for cheap labor. The same can be said for the non-accredited pain fellowships. They throw out some big name and 'let' you work for them getting a fellow's salary. Then what you have is non-recognized skills.
Hope this helps.