MONDAY, April 27 (HealthDay News) -- Circumcision does not decrease a man's sexual pleasure or function, but it does help reduce his risk of contracting the AIDS virus and suffering a penile injury, according to two new studies.

Austrian researchers analyzing biopsies from 20 circumcised and uncircumcised men found that the inner foreskin of the penis contains a higher concentration of Langerhans cells -- a prime target of the human immunodeficiency virus, or HIV -- than any other part of the male foreskin. Because this would make the inner foreskin more susceptible to HIV, removing it through circumcision would help lower a man's risk of contracting HIV, they concluded.

In the second study, a two-year study of nearly 3,000 Kenyan men found that those who were recently circumcised were less likely to suffer coital injuries, such as scratches, cuts, scrapes or soreness, than those who had their foreskin intact. Sexual function was determined to be similar between the circumcised and uncircumcised groups, according to the research team, which was from the United States, Canada and Africa.

The studies are to be presented this week in Chicago at the annual scientific meeting of the American Urological Association.

"These are important reports which support the concepts that circumcision does not interfere with sexual function and that circumcision is an important element of HIV prevention in sub-Saharan Africa," association spokesman Dr. Ira D. Sharlip said in a news release issued by the organization.

"At the same time, it should be emphasized that circumcision must be combined with other techniques of HIV prevention, such as safe sex and voluntary testing," he said. "It is not sufficient to rely on circumcision alone to prevent HIV transmission."

More information

The U.S. Centers for Disease Control and Prevention has more about HIV and circumcision.

MONDAY, April 27 (HealthDay News) -- A "nanoparticle" topical treatment for erectile dysfunction appears to work well, at least in a study involving rats.

According to the researchers, five of seven rats developed erections after their penises received a coating of a special hybrid of nanoparticles that slowly released nitric oxide (NO), which relaxes cells in the penis to help blood vessels open, bringing in more blood and swelling the tissues.

The rats' average erectile response to the treatment was about an hour, according to the research team headed by members from Albert Einstein College of Medicine in the Bronx, N.Y.

Erectile dysfunction, which is estimated to affect up to 30 million American men, can range from being able to only briefly sustain an erection to not being able to achieve one at all, according to the U.S. National Institute of Diabetes and Digestive and Kidney Diseases. Several types of oral or injectable medications are currently available to manage the condition.

The study is scheduled to be presented this week in Chicago at the annual scientific meeting of the American Urological Association.

"This is a very interesting concept which has potential to impact treatment of many conditions, including erectile dysfunction, if it can be translated from the animal lab to clinical practice," American Urological Association spokesman Dr. Ira D. Sharlip said in a news release issued by the organization. "It remains to be seen whether the effect of the nanoparticle technology is a local or a systemic effect."

More information

The American Academy of Family Physicians has more about erectile dysfunction  .

THURSDAY, April 23 (HealthDay News) -- Although the rate of complications during pregnancy has remained unchanged since 1993, the percentage of pregnant women with preexisting conditions, such as high blood pressure and diabetes, has increased, a new study finds.

The scientists speculated that the increase was driven by more obese women and more older women having babies. Both obesity and the mother's age have been linked to increased complications during pregnancy and delivery, according to researchers from the U.S. Centers for Disease Control and Prevention.

"There's the good news and the bad news," said study co-author Dr. William Callaghan, a senior scientist in the CDC's Maternal and Infant Health Branch in the Division of Reproductive Health. "The good news is that we are seeing some improvements. The bad news is that some of the traditional complications of pregnancy -- hemorrhage and hypertension -- are increasing."

Why these problems are on the rise is not clear, Callaghan said. "It would be great to understand why and, to the extent they are preventable, prevent them," he said.

The report is published in the May issue of Obstetrics & Gynecology.

For the study, Callaghan and his CDC colleagues used data from the National Hospital Discharge Survey to estimate the rate of pregnancy and delivery complications, including preexisting medical conditions and cesarean delivery. They compared data from 2001 to 2005 with data from 1993 to 1997.

They found that the overall rate of delivery complications held steady at 28.6 percent. However, the prevalence of preexisting medical conditions among women delivering infants increased, from 4.1 percent to 4.9 percent.

High blood pressure, preeclampsia, diabetes, asthma and bleeding after delivery all increased, raising concern among the researchers. "This is something we are not going to see go away," Callaghan said.

"There is no question hypertension is increasing," he said. "Again, it is unclear exactly why. We know it is associated with older women, we know it is associated with first pregnancy and we know that there are more older women having first pregnancies."

But obesity, which is also associated with high blood pressure, is increasing and may be a reason as well, he said.

At the same time, the rate of lacerations from episiotomy decreased, the study found. This may have something to do with the increasing number of cesarean deliveries, Callaghan said.

The rate of cesarean delivery increased, from 21.8 percent from 1993 to 1997 to 28.3 percent from 2001 to 2005, the researchers reported. The reason for this increase is also unknown, Callaghan said.

"It may reflect an increase in the risk status of women who are getting pregnant, especially older women and women who are coming into pregnancy with chronic diseases," he said. "It also reflects changes in practice patterns and how physicians make decisions about when a cesarean is warranted."

Dr. Edmund F. Funai, chief of obstetrics at Yale University School of Medicine, said he thinks the authors were "spot-on in their conclusions."

"While studies derived from administrative data must be interpreted with caution, it is very true that more births are occurring in older women than ever before," Funai said. "One natural byproduct of aging is the likelihood of accruing chronic disease diagnoses, such as hypertension. Compounding this fact is the rise in the prevalence of obesity, which itself is associated with morbidities such as hypertension and diabetes. The effect of aging and obesity is also likely synergistic."

However, classifying cesarean delivery as morbidity does not seem to be seem relevant any longer, Funai said.

"Many patients and providers are more interested in being able to schedule a birth, rather than awaiting spontaneous labor," he said. "Also, an increasing number of women seem to be most interested in maximizing fetal safety via cesarean, even if it means a disproportionate maternal risk as a trade-off. This is a cultural shift among patients that is still evolving."

More information

The U.S. National Women's Health Information Center has more on childbirth.

MONDAY, Jan. 26 (HealthDay News) -- Mothers who breast-feed are less likely to neglect their children, Australian researchers report.

In their study, the scientists followed 7,223 Australian women and their children for 15 years and found that the longer a mother breast-fed her child, the lower the risk of neglect.

Mothers who breast-fed for less than four months were twice as likely to neglect their children as those who breast-fed four months or more. Women who didn't breast-feed were 3.8 times more likely to neglect their children as mothers who breast-fed for at least four months.

Even after they adjusted for other factors, such as socioeconomic status, substance abuse and depression, the researchers found a strong association between breast-feeding and motherly care.

The findings were published in the February issue of Pediatrics.

Previous research has suggested how breast-feeding may help form a strong mother-infant bond, study senior author Dr. Lane Strathearn, an assistant professor of pediatrics at Baylor College of Medicine and Texas Children's Hospital, said in a Baylor news release.

"Oxytocin is a critical hormone produced during breast-feeding that promotes and reinforces maternal behavior. Animal studies have shown that this hormone is critical for the initiation of maternal behaviors in animals," Strathearn said. "It may be that breast-feeding stimulates oxytocin production in the brain, helping to develop the attachment relationship of the mother and her baby. Or the factors that help shape the development of the oxytocin system in the brain may predispose to successful breast-feeding and nurturance of the baby."

"Promoting breast-feeding may be a simple and cost-effective way to strengthen the mother-infant relationship. Providing the economic and social support for new mothers to stay at home with their babies may help accomplish this goal. The simple fact that women have such limited maternity leave inhibits them from strengthening this relationship," Strathearn said.

"Maternal neglect represents a fundamental breakdown in the relationship between a mother and her child, as the mom fails to provide the physical and emotional caregiving that an infant requires for optimal development. Breast-feeding may be a natural way to support the mother-infant relationship, reducing the risk of neglect in the long term."

More information

The U.S. National Institute of Child Health and Human Development has more about breast-feeding.