Once, it was simple. You took your baby to the pediatrician and he got his shots. But for some years now, a growing number of moms and dads have been struggling with the decision to inoculate or not. They may waver because of the clamor of news reports about possible links between vaccines and terrifying side effects. Or they're put off by the number of shots recommended -- up to 20 before age 2.

Emotions run high for other reasons too. Often, parents who choose not to have their children vaccinated are enraged that public-health policy makes it so difficult to avoid what they see as a dangerous practice. At the same time, those who do get their children inoculated can be just as angry that exposure to unvaccinated kids may raise the risk of disease for their own kids -- indeed, for everyone.

Once, it was simple, but no longer, and many parents are grappling with what they feel is a life-and-death decision.

Margaret Renkl is a contributing editor to Parenting.