WEDNESDAY, Sept. 26 (HealthDay News) -- Male DNA and cells are commonly found in some women's brains and most likely come from male fetuses, according to a small new study.

The medical implications of male DNA and male cells in women's brains are unknown. Previous studies of microchimerism -- the presence of genetic material and cells that were exchanged between fetuses and mothers during pregnancy -- have linked it to autoimmune diseases and cancer in both helpful and harmful ways.

Researchers at the Fred Hutchinson Cancer Research Center in Seattle analyzed brain autopsy specimens from 59 women who died between the ages of 32 and 101. Male DNA was detected in 63 percent of the women and was distributed in various brain regions. The oldest woman with male DNA was 94.

Thirty-three of the 59 women in the study had Alzheimer's disease. These women had a somewhat lower prevalence of male DNA, which was present in lower concentrations in regions of the brain most affected by Alzheimer's.

Because of the small number of women in the study and their largely unknown pregnancy history, it is not possible to establish a link between Alzheimer's disease and levels of male DNA and cells from a fetus, the researchers said in a cancer center news release.

They also added that the study does not show an association between male microchimerism in women's brains and their health or risk of disease. Further research is needed to investigate this area.

The study was published Sept. 26 in the journal PLoS One.

More information

Here's where you can learn more about microchimerism  .

FRIDAY, Sept. 28 (HealthDay News) -- Measuring progesterone levels in women with pain or bleeding during early pregnancy may help determine whether or not the pregnancy is viable, a new study says.

A viable pregnancy means that there is a reasonable expectation that it will result in a live birth. Progesterone is a hormone that plays a key role in pregnancy.

About one-third of women experience vaginal bleeding or pain in early pregnancy. Ultrasound is used to determine pregnancy viability but this test can sometimes be inconclusive, the authors of the new study pointed out.

Along with Dutch colleagues, researchers at the University of Birmingham in England analyzed the findings of 26 studies involving more than 9,400 pregnant women. Seven of the studies included women with pain or bleeding and an inconclusive ultrasound result, and 19 studies included women with pain or bleeding and no ultrasound.

The analysis showed that a single low progesterone measurement for women with pain or bleeding in early pregnancy can differentiate between a viable and non-viable pregnancy when an ultrasound result was inconclusive.

The progesterone test was less accurate in predicting pregnancy viability in women with pain or bleeding who did not have an ultrasound, according to a university news release.

The study was published online Sept. 28 in BMJ.

Low progesterone levels may occur in some viable pregnancies and the progesterone test should be used with another test to increase its diagnostic accuracy, the researchers concluded.

Because the new study was an observational review of prior studies, it did not conclusively prove that the progesterone test is a viable option for expectant mothers.

More information

The March of Dimes has more about vaginal bleeding during pregnancy  .

FRIDAY, Sept. 28 (HealthDay News) -- Postmenopausal women treated for breast cancer with drugs known as aromatase inhibitors have high rates of sexual problems, which is an important and underestimated issue, according to a new study from Sweden.

Nearly three-quarters of these women reported insufficient lubrication, 56 percent had pain during intercourse, half said their sexual interest was low, and 42 percent were dissatisfied with their sex life.

These percentages are much higher than for postmenopausal women who weren't treated for beast cancer, according to researchers Dr. Juliane Baumgart and colleagues at Orebro University and Uppsala University.

The study was published online this month in Menopause and appears in the February 2013 print issue of the journal.

Women taking tamoxifen for breast cancer treatment also had low sexual interest and more pain with intercourse, but had far fewer problems than women taking aromatase inhibitors, the study found.

Aromatase inhibitors block formation of estrogen from other hormones in the body. This may help prevent breast cancer recurrence and improve survival, the researchers explained in a journal news release.

However, there is a lack of effective treatment for the sexual side effects of aromatase inhibitors. Further research is needed to learn more about the causes and impact of these side effects in order to improve breast cancer survivors' quality of life, the researchers concluded.

While the study found an association between this class of drugs and sexual problems, it did not prove a cause-and-effect relationship.

More information

The American Cancer Society has more about aromatase inhibitors  .

THURSDAY, Sept. 27 (HealthDay News) -- A diet rich in antioxidants -- especially from fruits and vegetables -- can reduce the risk of heart attack in women, researchers report.

The new study included more than 32,500 Swedish women, aged 49 to 83, who filled out a questionnaire about their eating habits. During 10 years of follow up, more than 1,100 of the women suffered a heart attack.

Women with the highest antioxidant levels had a 20 percent lower risk of heart attack. These women consumed almost seven servings per day of fruits and vegetables, which was nearly three times more than the 2.4 daily servings consumed by those with the lowest antioxidant levels.

The study is published in the October issue of The American Journal of Medicine.

"Our study was the first to look at the effect of all dietary antioxidants in relation to [heart attack]," lead investigator Alicja Wolk, of the nutritional epidemiology division at Karolinska Institute in Stockholm, Sweden, said in a journal news release.

There are numerous types of weight-loss diets, but those that emphasize increased consumption of fruits and vegetables may be the most effective, journal managing editor Pamela Powers Hannley wrote in an accompanying commentary.

"Yet only 14 percent of American adults and 9.5 percent of adolescents eat five or more servings of fruits or vegetables a day," she noted.

Although the research found an association between increased consumption of antioxidants and a lowered risk of heart attack, it did not prove the existence of a cause-and-effect relationship.

More information

The U.S. National Heart, Lung, and Blood Institute has more about women and heart disease.