As the H1N1 influenza vaccine trickles into clinics and pharmacies over the next few weeks, public health officials and doctors desperately hope that pregnant women will be at the front of the line for the shot. Past influenza pandemics have proved that they're at increased risk for severe complications—and they appear to be even more vulnerable to this new flu strain. But pregnant women have a well-established antipathy toward vaccinations, with only 15% getting the flu vaccine in any given year, compared with 30% of the general population.