I currently live in Winnipeg, but I have lived all over the world (Toronto, New York, Dublin, Tokyo, etc.). I'm not certain why your doctor would refuse you a booster. That seems ridiculous, especially when you are of child-bearing age. I have never had a single issue getting my 10 year booster in any city that I have ever lived in. If a doctor did refuse, I would ask for my titres to be drawn, and/or his reasoning for the refusal, and I would probably change doctors. I travel a lot so I have an immunization record that I keep in order to help me remember my timing for vaccines, because I often have to take some odd ones that aren't routine in Canada. MMR, however, is routine. Every 10 years has always been the suggestion, but most health professionals believe that at a certain point you end up retaining immunity. The problem is that retention depends on the person, so the suggestion of every 10 years is preventative; at the very least it is important until you are 45 and aren't likely to get pregnant. If you get rubella when pregnant your baby will have major issues and could possibly die. I would ask your doctor which is more difficult - giving you another shot or having potential issues with your unborn baby? Obviously the MMR does lose potency, or so many people on here would not been complaining about their lack of immunity. I honestly don't understand what your doctor is talking about. I am 39 and have been routinely boostered for a variety of things all of my life, from a variety of doctors, in a variety of countries, most of whom, when I ask about titres, just say that it's easier for them to give me the booster than worry about drawing blood first. You do have to ask about your vaccinations though; doctors are usually too busy to keep track. I have a card that a doctor gave me at some point along the way and I just write it down, or he does when he gives me the vaccination.
Sorry Jessmke that your doctor is being an idiot. It legitimately concerns me that even some doctors are being complacent about vaccinations. And his excuse that your only option is to get your titres drawn is bogus. Doctors have a lot of leeway to use their professional judgement.