While the risk of death from childbirth is very small, more and more U.S. women are dying due to, what experts believe to be partly to blame, the increasing maternal obesity and the rise in Caesarean sections.

Rising to its highest U.S. maternal mortality rate in decades, it accounts for 13 deaths in 100,000 live births in 2004, according to statistics released by the National Center for Health Statistics. While the death of infants is much more common, with the nation's infant mortality rate at 679 per 100,000 live births in 2004, death from childbirth remains fairly rare in the United States.

Deaths from childbirth were a much more common tragedy 90 years ago where nearly one in every 100 live births resulted in a mother's death. However, many people find it hard to understand how in this age of hi-tech hospital facilities and advanced medical breakthroughs that maternal deaths still happen just like that.

The rising C-section rate at 29 percent of all births have been related to anesthesia, infection, and blood clots. One of the leading causes of pregnancy-related death is excessive bleeding, followed by blood vessel blockages and infections. Women with several previous C-sections are at especially high risk.

Obesity can also be a factor, according to medical experts, as heavier women are more prone to diabetes and other complications. Having excess tissue and larger babies can make a vaginal delivery more problematic that may lead to more C-sections.

Another factor for greater risks in pregnancy-related deaths is the age of mothers. More women are giving birth in their late 30s and 40s, when complications risks are greater.

The following characteristics of the maternal mortality rate include:

?Race: Studies have found that the maternal death rate in black women is at least three times greater than is it is for whites. Black women are more susceptible to complications like high blood pressure and are more likely to get inadequate prenatal care.

?Quality of care: Three different studies indicate at least 40 percent of maternal deaths could have been prevented.

There are times when there is no clear explanation for a woman's death, such as the case of Valerie Scythes, a 35-year-old elementary schoolteacher, who died after a C-section at a hospital in New Jersey, the state known for its highest Caesarean section rate. Two weeks later, another teacher at the same school died at the same hospital after a C-section delivery. While Scythes died of a blocked blood vessel, the other woman died from bleeding. The connection between the two deaths had not been established.

Another mysterious case of maternal death was that of Elizabeth Davis, 37, who died of a heart attack after a massive loss of blood a day after a vaginal delivery at a Danville, Virginia hospital in September 2000. The cause of heavy bleeding was not clearly known and Tim, the husband, regret his failure to have an autopsy. He could not believe that anything could be wrong with the pregnancy as his wife was like a picture of health, having gone well with two previous births. A lawsuit against the hospital ended in a settlement while Ethan, the child born that day, is a happy second grade kid who just never had a mom.