Home > Weekly Newsletters > Family Health & Relationships

WEDNESDAY, Aug. 1 (HealthDay News) -- The hormone progesterone may help prevent preterm birth in some women, but it doesn't work for everyone.

A pair of studies in the Aug. 2 issue of the New England Journal of Medicine found that progesterone didn't help prevent preterm birth for women carrying twins or triplets, but it was helpful in women carrying a single baby who also had a condition known as short cervix.

"The phenomenon of preterm birth is complex and there are probably multiple pathways involved so, ultimately, we will probably have to have multiple solutions," said Dr. John Thorp, a co-author on the twin study and a professor of obstetrics and gynecology at the University of North Carolina at Chapel Hill.

Preterm birth is defined as birth that occurs before the 37th week of pregnancy. About 12 percent -- or one in eight -- of babies born in the United States are born preterm, according to the March of Dimes. The earlier a baby is born, the more likely it is that the baby will have health or developmental problems.

In the first study, researchers randomly assigned 661 women who were pregnant with twins to receive weekly injections of 17 alpha-hydroxyprogesterone caproate (17P) or a placebo injection. The injections began at 16 to 20 weeks of gestation and ended at 35 weeks.

The researchers found that 17P was not effective in preventing preterm birth. Delivery or fetal death before 35 weeks' gestation occurred in 41.5 percent of the pregnancies in the 17P group and in 37.3 percent of the pregnancies receiving placebo. Serious adverse events to the baby occurred in 20 percent of the 17P group and 18 percent of the placebo group, according to the study.

"This therapy that we hoped would be a magic bullet in the prevention of preterm birth was not effective for twins," Thorp said.

In the second study, researchers compared the use of vaginal progesterone to a placebo in women with a short cervix. A short cervix develops sometime during early to mid-pregnancy, according to Dr. Robert Welch, chairman and program director of obstetrics and gynecology at St. John's Providence Hospital in Southfield, Mich. Experts aren't sure exactly what causes a woman to develop a short cervix, but it's not something that can be predicted ahead of time, he noted.

For this study, British researchers measured the cervical length of nearly 25,000 pregnant women. They found 413 (1.7 percent) had a short cervix. From that group, they randomized 250 of the women to receive either 200 milligrams of vaginal progesterone, administered nightly, or a placebo.

In this population, researchers found a significant benefit from the progesterone therapy. Delivery before 34 weeks of gestation occurred in 19.2 percent of those receiving progesterone vs. 34.4 percent of those on placebo.

"This study certainly gives hope to women diagnosed with short cervix," said Welch, who added that progesterone is a fairly inexpensive treatment, generally costing less than $100 for therapy throughout pregnancy. And, he said, it appears to be safe to use in pregnancy.

As to why one study showed a benefit while the other didn't, Thorp said it's likely that there are likely numerous pathways or mechanisms that lead to preterm birth, and there will likely have to be numerous therapies to prevent each type of preterm birth. It could also be that one study used injectable progesterone, while the other was administered vaginally, or it might be that twins or triplets need higher doses of progesterone.

"There are a lot of things we try to prevent preterm birth, but few are effective. In women with a history of preterm delivery, preliminary studies have shown progesterone can reduce preterm birth and there are no birth defects associated with it. We don't have anything else to offer women with a history of preterm birth. And we haven't had really had anything to offer women with a short cervix up to this point. Unfortunately, it looks like with twins, we still don't have a lot to offer," Welch said.

More information

To learn more about preterm labor and birth, visit the March of Dimes  .

THURSDAY, July 19 (HealthDay News) -- Variations in three genes play a critical role in how different people infected with HIV respond during the early stages of their infection.

This finding, detailed in the July 20 issue of Science, could help scientists find vaccines as well as new treatment targets for people infected with the AIDS-causing virus.

"There are new mechanisms of control of HIV1 that are implicated by these findings," said study senior author David Goldstein, a professor of molecular genetics and microbiology at Duke University and director of the school's Center for Population Genomics and Pharmacogenetics. "We don't yet know how to capitalize on those new mechanisms to develop new treatments, but it establishes directions for exploring new treatment options."

The study results are the first to emerge from the Center for HIV/AIDS Vaccine Immunology (CHAVI), a seven-year project funded by the U.S. National Institute of Allergy and Infectious Diseases (NIAID) with a goal of understanding the genetic influences on early responses to HIV infection. Many more studies are planned.

"We're really only just getting started," Goldstein said.

"It is a very important study," said NIAID Director Dr. Anthony Fauci. "It's significant for a couple of reasons. First of all, it used a technique that is going to be increasingly used in the genetics of medicine and that is to do a genome-wide association study to try and identify genes or modifications of genes which we call polymorphisms that are associated with certain expression of disease."

People infected with HIV have widely varying responses to their infection, with some falling sick quickly and others successfully fighting off full-blown AIDS for years or even decades.

One measurable difference is the level of circulating virus in the blood during the "stable" period after a person is infected but before he or she develops symptoms. This "viral load" is generally an indication of how well the person's immune system is fighting off the infection.

The new study searched for genetic differences that might explain variations in viral loads.

"One of the big questions in HIV is what are the determinants of the great variability in individuals being able to handle the virus. That's a big, big open question," Fauci said. "One of the ways to address that is to say look, there are some people whose viral set point, the level at which the body holds the virus in the absence of therapy, that varies enormously from person to person. We have no idea why that's the case. This study came up with three gene polymorphisms which appear to be associated very strongly with the ability to set the viral load. The combination of those explains about 15 percent of the variation in viral load among patients."

"The approach that we've taken is to use these natural differences among individuals in how well they can control the virus after infection as a pointer to new ways to act against the virus," Goldstein said. "That variation is huge. Some can push viral levels so low they will never progress to AIDS, whereas others can hardly contain it."

It took the international team of geneticists 18 months to identify the three crucial genes. In the end, they identified 486 appropriate patients from a possible universe of 30,000 people worldwide, and did genome-wide scanning on these patients. The study participants could not be undergoing treatment (as this would affect viral load levels), they had to know when they became infected, and there had to be high-quality laboratory estimates of their viral load.

This was the first time a genome-wide approach has been used for an infectious disease, the researchers said.

Two of the gene variants -- or polymorphisms -- were found in genes controlling the human leukocyte antigen (HLA) system, which helps identify foreign invaders and tags them for destruction. These genes, HLA-A and HLA-B, are switched off by HIV when it enters the body so the immune system is no longer able to recognize the virus as foreign.

Research published in the May 13 issue of Nature Genetics also implicated the HLA-B gene. That study found that HLA-B, in combination with another gene, KIR3DL1, might confer some protection against AIDS progression.

But HIV doesn't seem to be able to shut off HLA-C, the third gene variant identified by the researchers behind the new study. "This had not been a focus of attention in the past because it was not known that it is important in the control of HIV," Goldstein said. "We've now implicated this part of the immune response as being important so it now becomes a focus."

"It might be that this gene represents a vulnerable point for HIV," he added. "As far as we know, HIV can't act against it."

The three gene variants identified in the study explain 15 percent of the variability in how well people contain their viral load. "In genetic terms, that's a lot," Goldstein said. "These are very important genetic effects."

The next CHAVI study will look at what factors might protect people from becoming infected with HIV in the first place.

More information

Visit CHAVI   for more on cutting-edge HIV/AIDS research.

FRIDAY, July 6 (HealthDay News) -- A substance present in the body as a result of inflammation may also help cause male infertility, new research suggests.

A team at The Feinstein Institute for Medical Research in Manhasset, N.Y., identified unusual levels of a substance called "macrophage migration inhibitory factor" (MIF) in semen samples obtained from infertile men.

Reporting in the current issue of Molecular Medicine, the researchers theorize that identification of this factor could lead to tests for infertility as well as the development of a male contraceptive.

Inflammation occurs when the body endures infections such as sepsis (blood infection), autoimmune disorders such as rheumatoid arthritis or chronic diseases such as diabetes and heart disease. The factor is present in high levels during those conditions and is linked in some cases to tissue damage.

The researchers analyzed semen from 27 fertile men and 68 infertile men after several days of sexual abstinence. They found that men with fertility problems had MIF levels that were either too low or too high.

Healthy levels of MIF help sperm mature so they can unite with an egg, the team said. When they added the factor to Petri dishes containing healthy sperm, the number and mobility of the sperm decreased.

According to the U.S. Centers for Disease Control and Prevention, there are 2.1 million infertile couples in the United States. Almost 40 percent of infertility problems are due to the male.

More information

To learn about infertility, visit the National Infertility Association  .

THURSDAY, May 17 (HealthDay News) -- People at risk for drinking problems are more likely to marry someone who's also at risk for alcohol dependence, according to a team of American and Australian researchers.

Reporting in the May issue of Alcoholism: Clinical & Experimental Research, the researchers studied almost 6,000 twins born in Australia between 1902 and 1964. They also spoke with more than 3,800 of the twins' spouses.

"As they say, 'like marries like,'" first author Julia D. Grant, a research assistant professor of psychiatry at Washington University School of Medicine in St. Louis, said in a prepared statement.

"Spouse selection is not a random process, and we call this non-random mating. People tend to choose mates who are similar to them, not only from the same neighborhood or socio-economic background but also alike in personality and other behaviors. We found that people at risk for alcohol dependence tend to marry others who are at risk," Grant said.

But she and her colleagues said this doesn't necessarily mean that both spouses will end up with drinking problems. In some cases, one spouse's excess alcohol consumption may actually lower the risk that the other spouse will abuse alcohol.

"We don't really know how this works," Grant said. "It is possible that an individual decreases his or her alcohol consumption in reaction to the other's excessive alcohol use. Maybe one person is responsible for getting the kids up and out for school in the morning, for example."

She noted that alcohol dependence is influenced by both genetic and environmental factors, such as employment, interests, family and friends.

"There's lots of room for different factors to influence the behavior of two people who are married. One spouse could work at a place where the co-workers go out for a drink after work. Or one spouse could be a regular churchgoer, while the other prefers to sleep," Grant said.

More information

The American Medical Association has more about alcohol abuse and alcoholism  .