WEDNESDAY, May 28 (HealthDay News) -- Premature births of single babies in the United States have been on the rise in recent years, and a new report finds that Caesarean sections account for nearly all of the increase.

"I think this is the first time an in-depth analysis has been done on these two increasing problems," said Dr. Alan Fleischman, medical director and senior vice president of the March of Dimes. Investigators from the March of Dimes, the U.S. Centers for Disease Control and Prevention, and the Albert Einstein College of Medicine collaborated on the report, which was expected to be published in the June issue of Clinics in Perinatology.

Researchers looked at national birth data from 1996 to 2004, and found an increase of almost 60,000 singleton preterm births, most of those delivered by C-section. "The analysis revealed that 92 percent of the increase in singleton premature birth is due to C-sections," Fleischman said. "That is an amazing statistic."

While single-baby preterm births rose by about 10 percent during this nine-year period, the C-section rate for the group rose 36 percent, the researchers found.

Preterm birth -- delivery before 37 weeks of gestation -- boosts the risk of death in the first month of life. More than 520,000 babies are born too soon each year in the United States -- that's one in eight. Those born "late preterm," from 34 to 36 weeks, accounted for most of the rise in the preterm birth rates for singletons. And the babies face not only a higher risk of death, but also a host of health problems such as respiratory difficulties, feeding problems, jaundice and delayed brain development.

Fleischman said the advice about preterm birth from the American College of Obstetricians and Gynecologists is clear. "ACOG says no one should be induced before 39 weeks unless there are clear medical indications," he noted. The March of Dimes is in agreement with that advice, he added.

Among the medical reasons to induce are uterine infection or high blood pressure caused by the pregnancy (preeclampsia), among others.

While there are clear medical indications for C-sections, Fleischman suspects the "convenience" factor may be coming into play.

Experts have long suspected that the rise in C-sections was linked to an increased in preterm births, Fleischman said. "The challenge now is to sort out what percent of these C-sections are based on less than optimal medical indications," he said.

As for women requesting C-sections for convenience, Fleischman said that when they consider requesting early delivery before 39 weeks, they really need to understand that babies born before that time are at risk for problems.

The message of the study is clear, said Dr. Jennifer Wu, an obstetrician- gynecologist at Lenox Hill Hospital in New York City. "This is studying a large population, and it's warning doctors about the risk of an early delivery," she said.

All factors need to be balanced when trying to decide whether inducing an early delivery is wise, she said.

"If you are inducing early, it should be [for] a medical reason," Wu said. One example is a patient at risk of stillbirth, she said. "If you advise a patient, 'You are at risk for stillbirth, we would like to induce you early,' you have to make sure the [child's] lungs are mature."

If an obstetrician suggests delivering before 39 weeks, Fleischman advised women to ask why it is being suggested and what will happen if they do not. Those questions, in turn, he said, will hopefully help the physician and the patient make the best decision.

More information

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

WEDNESDAY, May 28 (HealthDay News) -- A new compound that inhibits HIV protease has been developed by researchers at the University of Michigan.

The protease, which is necessary for HIV replication, is a common target in the treatment of HIV patients. But this is the first new HIV protease inhibitor compound to be developed in 20 years and could lead to a new class of HIV/AIDS drugs, according to the researchers, who created the compound using computer models and then confirmed its effectiveness in laboratory tests.

This new compound debilitates the HIV-1 protease in a different way than current protease inhibitors, which bind to the center of the protease, freezing it closed, and preventing it from processing the proteins needed to assemble an active virus.

The new compound targets a different area of the protease and holds it open, which also inhibits its activity.

"In a way, this works like a door jam. If you looked only at the door when it's shut, you'd not know you could put a jam in it. We saw a spot where we could block the closing event, but because everyone else was working with the closed form, they couldn't see it," principal investigator Heather Carlson, a professor of medicinal chemistry in the College of Pharmacy, said in a prepared statement.

The new compound's molecules are smaller, which means they're absorbed much more easily.

"This new class of smaller molecules could have better drug properties (and) could get around current side effects," Carlson said. "HIV dosing regimes are really difficult. You have to take medicine several times a day. Maybe you wouldn't have to do that with these smaller molecules, because they would be absorbed differently."

Research into this new compound is still in the preliminary stages, she noted.

"It's very easy to make an inhibitor, [but] it's hard to make a drug. This compound is too weak to work in the human body. The key is to find more compounds that will work by the same mechanism," Carlson said.

More information

The National Institute of Allergy and Infectious Diseases has more about HIV treatment.

WEDNESDAY, May 7 (HealthDay News) -- Women with high blood sugar levels during pregnancy face an increased risk of complications, even if the high blood sugar readings don't meet the criteria for gestational diabetes.

In a large, international study, researchers found that for each standard deviation increase in blood sugar, there was a greater risk of complications, such as having a large birth weight baby or needing a Caesarean section delivery.

"We found strong independent associations between a mother's blood sugar levels during an oral glucose tolerance test and 28 weeks of gestation and the pregnancy outcomes," said the study's lead author, Dr. Boyd Metzger, the Tom D. Spies professor of metabolism and nutrition at the Feinberg School of Medicine at Northwestern University in Chicago.

What this means for pregnant women right now, however, isn't clear.

"Because the relationship between the mother's blood glucose level and risk tend to be continuous and linear, it is not clear where the risk reaches the point where treatment should optimally begin," said Metzger.

"We were hoping there would be a breakpoint," explained another of the study's authors, Dr. Don Coustan, professor and chair of obstetrics and gynecology at the Warren Alpert Medical School of Brown University in Providence, R.I. "But, the relationship between glucose levels and outcomes were continuous, which means it will be difficult to decide where to put the 'treating' point."

Coustan added that there will be a conference in June where pregnancy and diabetes experts will likely debate the pros and cons of treating hyperglycemia. For now, he said, he suspects that "doctors will still use the glucose threshold they're currently using."

One thing that was clear from the study is that higher odds of complications, like an increased risk of C-section or a large baby, are related to high blood sugar and not to other conditions, such as obesity or older maternal age, according to Metzger.

Results of the study were published in the May 8 issue of the New England Journal of Medicine.

The study included more than 23,000 pregnant women from 15 centers in nine countries. None of the women had diabetes. All of the women underwent glucose tolerance testing between 24 and 32 weeks of gestation. This test is performed by first taking a fasting blood sugar reading, then having the woman drink a high-carbohydrate liquid -- in this case a 75-gram carbohydrate drink; 100 grams is standard in the United States -- and then rechecking blood sugar levels at one and two hours to assess how the body is processing the high sugar load.

The higher a woman's blood sugar levels were, the more likely she was to have a C-section, to develop preeclampsia, have premature delivery and to have the delivery complication known as shoulder dystocia, the study found.

Babies born to women with higher glucose levels were more likely to have high insulin levels, low blood sugar, and to have a large birth weight, all indications of exposure to high glucose levels.

The odds of these complications changed continuously as blood sugar levels rose. For example, a woman with the highest levels of blood sugar (but not diabetes) had large babies 26 percent of the time, compared to just 5 percent for women with the lowest blood sugar levels.

"Basically, what they found out is that there is no threshold where you know to treat. That makes it difficult to know what to do with these findings," said Dr. Joel Zonszein, director of the Clinical Diabetes Center at Montefiore Medical Center in New York City.

A second study in the same issue of the journal looked at the use of the oral diabetes medication metformin, versus insulin, the standard treatment for gestational diabetes. The study included 751 women, randomly assigned to receive metformin or insulin treatment.

The researchers found that metformin was well-tolerated, although almost 43 percent of the women eventually required the use of supplemental insulin. There were no serious adverse events reported for mother or baby from the use of metformin, according to the study.

Of this study, Zonszein said, "My guess is that until we have larger studies, there's not going to be a big change in recommendations, because we have so much experience with insulin." But, he added, many women and obstetricians may welcome these findings because "giving a pill is easier than giving insulin." He said another oral medication, glyburide, was also found effective in another small trial.

More information

To learn more about gestational diabetes, visit the American Diabetes Association  .

TUESDAY, April 29 (HealthDay News) -- Screening for cervical cancer reduces the risk for all types of the disease in women of all ages, say Swedish researchers. They also concluded that better follow-up of women who have cervical cancer screening could lower rates of the disease.

The researchers reviewed data from the National Cervical Cancer Screening Registry on 1,230 cervical cancer patients diagnosed between 1999 and 2001, and 6,124 age-matched women who hadn't been diagnosed with cervical cancer.

Women who hadn't had a Pap smear screening test within the recommended three-year interval were 2.5 times more likely to be diagnosed with cervical cancer than women who had regular Pap tests. Women who didn't have regular screening were also nearly five times more likely to be diagnosed with advanced cervical cancer than those were had regular screening.

Regular screening reduced the risk for all types of cervical cancer and reduced the risk of women between ages 23 and 30, which were new findings, according to the researchers.

They noted that screening didn't completely protect women from cervical cancer. Women who were screened at the recommended interval and were found to have abnormal cells were 7.6 times more likely to develop cervical cancer than women who were screened and had normal results.

Women with abnormal Pap results accounted for 11.5 percent of all cervical cancer cases. This increased risk was not noted in women diagnosed with advanced cervical cancer.

The study was published online April 29 in the Journal of the National Cancer Institute.

The researchers said their findings show that irregular screening is the most important risk factor for incident cervical cancer and that abnormal smears, if not followed up by a biopsy, are also an important risk factor.

In an accompanying editorial, Jack Cuzick, of the Cancer Research UK Centre in London, emphasized the importance of systematic audits of cancer screening programs.

"Audits, such as the one described (in this study), need to become routine within screening programs if screening is to achieve its full potential," Cuzick wrote. These reviews identify areas of screening programs that are ineffective and need to be restructured and improved.

More information

The U.S. National Women's Health Information Center has more about cervical cancer.