Here's a May 2009 article from Baltimore news channel WJZ.com that says that murder is the #1 cause of death for pregnant women in Maryland, and sources this to a specific person at the Maryland Department of Health and Mental Hygiene:
Across Maryland, pregnant women are being killed at an alarming rate. Forty-one pregnant women have been murdered in Maryland since researchers began keeping track in the 90s.
"We were completely shocked to find that homicide was the leading cause of death," said Isabelle Horon, Md. Dept. of Health and Mental Hygiene.
The majority of these victims are young, single and African-American.
In December 2004, the Washington Post did a three part series on the murder of pregnant women. The lead article includes this:
Five years ago in Maryland, state health researchers Isabelle Horon and Diana Cheng set out to study maternal deaths, using sophisticated methods to spot dozens of overlooked cases in their state. They assumed they would find more deaths from medical complications than the state's statistics showed. The last thing they expected was murder.
But in their study, published in the Journal of the American Medical Association in 2001, they wrote that in Maryland, "a pregnant or recently pregnant woman is more likely to be a victim of homicide than to die of any other cause."
"It was a huge surprise," said Horon, who recalls paperwork covering the researchers' kitchen tables on weekends and evenings as they sought to understand the astonishing numbers. "We thought we had to have made a mistake. We kept checking and checking and rechecking."
Their findings, as it turned out, were no error. Homicide accounted for 50 of 247 maternal deaths in Maryland over a six-year period -- more than 20 percent. It had caused more deaths than cardiovascular disorders, embolisms or accidents.
"People have this misconception that pregnancy is a safe haven," Cheng said.
Building upon the Maryland study and others, The Post contacted 50 states and the District for all possible data about maternal deaths during pregnancy or postpartum months. Few states track homicides in a comprehensive way, but many states could provide some data, mostly from death certificates. The Post combined what it collected with cases culled from other sources.
The resulting 1,367 maternal homicides took place over 14 years.
"That's a formidable number -- and that's just the tip," said Judith McFarlane, who studies violence and pregnancy at Texas Woman's University and who described the void of reliable numbers as "embarrassing." She observed: "You can't address a problem that we don't document. You can't reduce them. You can't prevent them. In essence, they don't exist."
The Post did an indepth study of one year of the homicides they found to try to understand the motives:
One recent year of homicides -- 2002 -- was examined in greater detail to get a closer look at how and why the cases happened. For a group of 72 homicides in 24 states, The Post interviewed family members, friends, prosecutors and police. The analysis showed that nearly two-thirds of the cases had a strong relation to pregnancy or involved a domestic-violence clash in which pregnancy may have been a factor.
The dead included Ceeatta Stewart-McKinnie, 23, a college student in Richmond who was beaten to death by her boyfriend. The couple had dated on and off for years, and she had had abortions previously, prosecutors said. This time, he was married -- and she refused to end her pregnancy. Turkey hunters found her bludgeoned body in the woods.
In Chicago, Chavanna Prather, 17, was a high school student who played basketball and worked part time at McDonald's. Prather became intimate with her manager at work, then became pregnant and asked for money for an abortion, police said. She was found dead in a river on the city's South Side. He awaits trial.
In Rochester, N.Y., Zaneta Browne, 29, was at odds with her married boyfriend about her pregnancy in 2002 when he shot her with a .22-caliber rifle. The killer and his wife secretly buried her on rural land, hoping no one would find out. Browne left three children behind. She was nearly four months pregnant with twins.
Louis R. Mizell, who heads a firm that tracks incidents of crime and terrorism, observed that "when husbands or boyfriends attack pregnant partners, it usually has to do with an unwillingness to deal with fatherhood, marriage, child support or public scandal."
In the article, Pat Brown, a criminal profiler based in Minneapolis explains:
"It is certainly a more dangerous moment in life. You are escalating people's responsibilities and curtailing their freedoms."
For some men, she said, the situation boils down to one set of unadorned facts: "If the woman doesn't want the baby, she can get an abortion. If the guy doesn't want it, he can't do a damn thing about it. He is stuck with a child for the rest of his life, he is stuck with child support for the rest of his life, and he's stuck with that woman for the rest of his life. If she goes away, the problem goes away."
Jack Levin of Northeastern University is quoted as explaining:
"It seems to me that these guys hope against hope for a miscarriage or an abortion, but when everything else fails, they take the life of the woman to avoid having the baby,"