Once again, we were recently shocked to hear of another woman murdered while pregnant. This time it was Jessie Marie Davis, murdered near Canton, Ohio, during her ninth month of pregnancy.

Sundry definitions have been used to determine the frequency of various causes of death associated with pregnancy. One definition refers to pregnancy-associated death as any death occurring either during pregnancy or within one calendar year following delivery or termination of pregnancy.

Using this definition, a six-year study in Maryland ending in 1998 found that 21 percent of pregnancy-associated deaths from all causes occurred during the pregnancy itself, 36 percent within 42 days following delivery or pregnancy termination, and 43 percent within the subsequent 43 to 360 days.

During this one-year period, homicides accounted for the most deaths, 20 percent; the second leading cause of death, cardiovascular disease, was responsible for 19 percent of the deaths. Accidents accounted for a surprisingly low 7 percent of deaths. Of the deaths that occurred during the actual months of pregnancy, homicide was responsible for 43 percent, while most of the cardiovascular mortality occurred after the end of the pregnancies.

Another study, conducted between 1991 and 1999, reported that homicide was responsible for 31 percent of all pregnancy deaths. Among non-pregnant women between the ages of 15 and 45 in that study, homicide was the third leading cause of injury-related deaths, with traffic accidents ranking first and suicides second.

In the Maryland study, homicide accounted for only 6 percent to 11 percent of the deaths among women within the same age range who had not been pregnant during the previous year. Older studies from North Carolina, New York City, and Cook County, Illinois, concluded that between 13 percent and 26 percent of pregnancy-associated deaths were due to homicides.

Although murders are a relatively frequent cause of death among all women between 15 and 45, it does appear that women are murdered more often during the high-stress period of pregnancy and its aftermath. As in the case of the murdered Ohio woman, boyfriends and husbands are frequently responsible for these homicides, which appear to be more common among blacks and those faced with economic distress.

Every report of the shocking murder of a pregnant woman makes it seem like the problem has become more frequent, but there are no data to determine whether or not there has been an increase in pregnancy-associated murders.

Can the murders of pregnant women be prevented? The American College of Obstetricians and Gynecologists has recommended that obstetricians not only routinely screen all pregnant women for possible domestic violence during their prenatal care but also implement sensitive interventions when appropriate.

Pregnant women themselves need to level with their doctors and other family members about violence, whether only threatened or carried out, by their intimate partners.