Why would a woman kill for a baby? This is the question Dr. Oz posed to me for an upcoming segment on fetal abduction, which will air Tuesday, November 8th and features two survivors of this brutal and unspeakable crime. It turns out that these horrific attacks against expectant mothers are on the rise in the United States. Dr. Oz spoke to  Sarah Brady, who fought off her attacker to save her own life and the life of her unborn child. Both Brady and another survivor, Eli Evans, appeared on the show to tell viewers they have come out of this experience with a positive outlook on life – realizing they are lucky to be alive.

Related: Woman Selling Baby Clothes On Craigslist Allegedly Lured Pregnant Mother, Cut Unborn Child From Her Womb

But how in the world did fetal abduction become a “trend?” The idea of a pregnant woman being abducted and murdered so that another woman can claim the unborn baby as their own seems like something out of a horror movie. And while it’s a rare phenomenon, the percentage of fetal abductions have grown exponentially in recent years. Fortunately, the tricks and ruses employed by these demented killers have been identified by experts. While each fetal abduction case is unique, here are some of the clear patterns:

• The killer is a woman who pretends to be pregnant for months, almost to full term.
• The killer often targets an acquaintance or someone they’ve befriended on the internet.
• The killer is usually desperate to produce a baby to keep a man in a relationship.
• The killer is driven by grandiose delusions and extreme narcissism.

The type of women who commit this crime use a series of ruses to make their pregnancy seem real. They not only wear pregnancy suits and outfits, they go so far as to create a nursery in their home, buying diapers, baby clothes, and formula, and some even hold baby showers. Many of these women carry a sonogram around with them, showing people the baby they are about to deliver. How do they get this private data? Through easy access to information about pregnant woman on the internet. Particulars about expectant mothers can be mined from Facebook, from chat rooms, and through online baby registries. The killer decides on her target and then befriends the expectant mother, often through an act of generosity such as an offering “extra” baby clothes or diapers.

Related: Woman Allegedly Stabs Pregnant Childhood Friend To Death, Cuts Baby From Her Womb

In this bizarre crime of “caesarean kidnapping,” a woman lures an expectant mother into a deadly trap with the belief that she can kill the mother and successfully save the baby. It sounds too crazy to be true, but watch the story of the deranged attack on mother-to-be, Sarah Brady, where a woman posing as “Sarah Brody” created a web of deception and actually planned to use crude surgical tools to extract Sarah’s child. As I told Dr. Oz, this is not the act of a woman who wants to be nurturing. This is the act of a cold-blooded killer who plots and plans the crime with a predatory instinct. While most mothers and babies do not survive these brutal attacks, Dr. Oz also had Eli Evans on the program, a boy who was snatched from his mother’s womb, but miraculously survived. Eli tells his emotional story and says he wants to take an active role in helping other victims of violent crimes. The segment is bizarre, extraordinary, and inspiring at the same time. Stay tuned and stay informed!

Main Image: Samuel Evans, center, the father of Debra Evans who was murdered along with her two oldest children in 1995, addresses the media with his daughter Wendy Williams, left, and Katy Salhani, right, sister of Evans, holds up a photo of the children via AP Photo/Steve Matteo