The death of Laci Peterson and her unborn son Conner has brought national attention to a little known but growing trend and that is that murder is the number one cause of death among pregnant women.

As shocking as it may seem, at a time when women are at their most trusting and vulnerable, many of them fall prey to their intimate partners.

Here we examine this disturbing phenomenon. Through the personal stories of women who have died, interviews with leading experts and the words of a man who actually killed his pregnant wife, we'll get a first-hand look at why pregnant women are dying and we'll provide some warning signs for women everywhere.