I have declined it every pregnancy. This time my OB strongly pushed it at my initial 7 wk visit, and asked me to review the "new research" before deciding, and handed me a paper stating that "thimerosol has never been shown to cause harm" (which is false, and skirting the issue because it has never been tested in pregnant women) AND that the "flu shot is safe in any trimester" (it has NOT been tested in pregnant women and the vaccine insert clearly states as such, and goes on to specify that it should only be given when CLEARLY needed). I really can't even qualify how to argue with non-research and baseless claims.
The fact that they have been giving the flu shot to hundreds of thousands of women for years now, and not one single person or institution has ever done any type of follow up on baby's health, speaks volumes. If they are so convinced it is safe, it wouldn't be hard to find a population and do an epidemiological study. They don't need to prove safety because it is on the recommended list, so they have nothing to lose by not testing, and they have no liability for ill effects. That simply doesn't seem to be in the best interest of mother or child.
For enlightening reading about the "trace" amounts of mercury, google "What your doctor may not tell you about the flu vaccine" or check out this link.
The year that both the H1N1 AND the seasonal flu vaccine were given, there was a huge spike in miscarriages reported to VAERS after the shot. I personally know two people who miscarried within 48 hrs of the shot (in their first trimester). That seems a huge coincidence.