WEDNESDAY, April 13 (HealthDay News) -- While the rate of stillbirths in the United States has dropped over the past few decades, this tragic outcome is still a reality for far too many couples, experts say.

As part of a series of studies published online April 14 in The Lancet, researchers report that a leading cause of stillbirth in the United States may be obesity, which can raise the risk for fetal loss.

Obese women are more likely to have diabetes and hypertension, and "these are two of the major causes of stillbirth," noted the lead author of one paper, Dr. Robert L. Goldenberg, a professor of obstetrics and gynecology at Drexel University College of Medicine in Philadelphia. "But for reasons that are not clear, above diabetes, above hypertension, obese women are still more likely to have a stillbirth [than thinner women]."

Limits on women's access to good obstetric care -- most notably for poor or minority mothers-to-be -- is another major contributing factor. "My estimate is that if all women had access to very good care, a third to half of the stillbirths in the U.S. could be eliminated," Goldenberg said.

The definition of stillbirth varies country to country. In the United States, it's typically defined as fetal loss at 20 weeks or more of gestation, while the World Health Organization defines it as fetal death at 28 weeks or later.

Stillbirths are even more prevalent in less affluent countries. In fact, worldwide the problem accounts for more than 2.6 million fetal deaths each year. Ninety-eight percent occur in low-income countries, but wealthier countries, including the United States, also experience many stillbirths each year, researchers say.

"Stillbirth does not receive the focus it deserves, because it is a major pregnancy outcome that has been neglected," said Goldenberg. "In the United States there are about 27,000 stillbirths every year," he added. "It's as common a bad outcome as infant mortality, and it's way more common than babies infected with AIDS."

Yet, stillbirths are not often recorded in infant mortality data, Goldenberg said. In addition, in the United States there remains a large disparity in the number of stillbirths between white and black women, he said, with black women at much higher risk. Similar disparities also exist between urban and rural women and between poor women and richer women.

"It is disadvantaged women that tend to have stillbirths much more often," Goldenberg said. "That's predominately because of access to care."

Dr. Cathy Spong, chief of the Pregnancy & Perinatology Branch at the U.S. National Institute of Child Health and Human Development, and author of an accompanying journal editorial, said that the disparities seen in stillbirths are the same ones seen in other adverse pregnancy outcomes.

These disparities "not only occur in stillbirth, it occurs in preterm birth and also in infant mortality," she said. "So, as you look at conditions in pregnancy, and the bad things that can happen you see consistent disparity."

The good news is that over the last 30 years there has been a substantial reduction in stillbirths in the United States, Goldenberg said. "Fifty years ago, the stillbirth rate was 50 per 1,000 births, to day it's between three to six per 1,000," he said.

"We have done very well, but there is still more to do." Goldenberg said. "It's mostly due to good obstetric care that most women in the United States get," he said. "But women who don't have access to timely care have as much a fourfold increased risk of stillbirth.".

According to Goldenberg, stillbirths typically occur die to major "catastrophes" during labor. These can include bleeding, seizures, prolonged labor or the baby not getting enough oxygen. "Most of those conditions are easily fixed in a good hospital," he said. "Women who don't have access to hospitals are the ones much more likely to have a still birth.

In other wealthy nations, such as Norway, Sweden and Denmark, the rates of stillbirths are about half of the rate in the United States, Goldenberg said.

Goldenberg noted a stillbirth can take a psychological toll on the mother and the family.

"Every woman who is pregnant has a vision and a hope of a live baby," he said. "When a stillbirth occurs the woman and family are often devastated, but because in many places there is no recognition of the death there is none of the normal kinds of grieving that would happen if you lost a live child," he said.

"Most women view the baby as a child of theirs that happened to be born dead, not that it didn't exist," Goldenberg added. The mother and family should be encouraged to grieve for this lost life and not hide it, he said.

"When it's hidden the women doesn't have a chance to work through it," Goldenberg said.

In addition to counseling, many hospitals encourage the mother to hold the infant and name him--to make the infant real, Goldenberg said. "Family members are encouraged to acknowledge that this is a birth and a death: this was a child," he said.

Summing up, Goldenberg listed three important messages about stillbirth: it is an important pregnancy outcome that needs to be paid attention to; it is, for the most part, preventable, and "when it happens, it is not the woman's fault."

More information

For more information on stillbirths, visit the March of Dimes.