A groundbreaking clinical study of a new method for preventing premature birth in millions of women each year, published in the medical journal Ultrasound in Obstetrics & Gynecology, shows that the rate of early preterm delivery in women (< 33 weeks) can be reduced by 45 percent – simply by treating pregnant women at risk with a low-cost gel of natural progesterone during the midtrimester of pregnancy until term.
The peer-reviewed findings were led by the Perinatology Research Branch of the National Institutes of Health, housed by the Wayne State University School of Medicine at Hutzel Hospital in Detroit. The findings are certain to have substantial impact on the practice of medicine, according to the principal investigator of the three-year clinical trial.
The study is entitled Vaginal progesterone reduces the rate of preterm birth in women with a sonographic short cervix: a multicenter, randomized, double-blind, placebo-controlled trial.
“The study published today offers hope to women, families and children,” said Dr. Roberto Romero, Chief of the Perinatology Research Branch of the NIH. “Worldwide, more than 12 million premature babies – 500,000 of them in this country – are born each year, and the results are often tragic. Our clinical study clearly shows that it is possible to identify women at risk and reduce the rate of preterm delivery by nearly half, simply by treating women who have a short cervix with a natural hormone - progesterone.”
Dr. Romero, principal investigator of the study, and Sonia S. Hassan, M.D., the lead author of the study and associate professor of obstetrics and gynecology in the WSU School of Medicine, also pointed out that numerous studies (many by the PRB) over the past decade have shown that ultrasound of the uterine cervix can identify pregnant women who are at high risk for preterm delivery. The ultrasound examination is simple to perform, painless, and can be performed between the 19th and 24th weeks of pregnancy. Pregnant women with a short cervix (one that is < 20mm) are at very high risk for preterm delivery.
Dr. Romero added that, once a high-risk mother for preterm delivery has been identified, she can be offered treatment with progesterone. Of major interest is that progesterone reduced the risk of preterm delivery not only at < 33 weeks, but also at < 28 weeks (one of the secondary endpoints of the study). It also reduced the rate of respiratory distress syndrome, the most common complication of premature babies.
"We believe that the data in our study speaks for itself – and we predict that it will have major implications for obstetrics."
"The findings of the study are especially good news for expectant mothers in Detroit," said Dr. Hassan. "Preterm delivery has long been a major healthcare problem in the city." In 2008, more than 17 percent of births Detroit were preterm – and they accounted for more than 70 percent of the infant mortality recorded in that year, according to the latest research from the Michigan Chapter of the March of Dimes.
The city's high infant mortality, preterm delivery rate and ethnic disparity in birth outcomes were important considerations in the NIH's decision to establish the PRB in Detroit nine years ago. The presence of the PRB in Detroit allows women to obtain state-of-the-art medical care and join medical studies to improve prenatal diagnosis, monitor fetal growth, predict preeclampsia and prevent preterm birth.
The study was conducted at 44 centers worldwide during the past three years. The study included patients from the United States, South America, Europe, Asia and Africa, and screened more than 32,000 women for a short cervix.
Describing the startling results, which showed that the rate of preterm birth among the women with a short cervix had been reduced by 45 percent, Dr. Hassan – director of the Wayne State/PRB/DMC Maternal-Fetal Medicine Fellowship Program – noted in the study: "The main implication for clinical practice is that universal screening of women with ultrasound examination in the midtrimester to identify patients at risk (based on a short cervix) can now be coupled with an intervention – the administration of vaginal progesterone gel – to reduce the frequency of preterm birth and improve neonatal outcome. This can be accomplished conveniently.
"We're obviously very gratified by these results," said Dr. Hassan. "Based on the findings of our clinical trial, we expect that obstetricians and clinicians will begin to consider providing expectant mothers with ultrasound screening for cervical length, and to make progesterone therapy available to those who present with a short cervix.
"Our group has been working on this approach to reducing infant mortality for much of the past decade, and it's very exciting to see that the effort is paying off, and that mothers and infants will soon be able to benefit from it."
"As a research university, Wayne State's mission is to discover and apply knowledge that contributes to the positive development and well being of society," said Valerie M. Parisi, M.D., M.P.H., M.B.A., Dean of the WSU School of Medicine. "Today's findings are an example of research that is quickly translated into improved clinical care outcomes. Wayne State will aggressively share this new knowledge with health care providers here in Detroit, in Michigan and around the world so that it can benefit pregnant women. I'm confident that the strong partnership between the PRB, the DMC and Wayne State will continue to result in pioneering contributions for pregnant women and unborn children."
About Wayne State University
Wayne State University is a premier urban research institution offering more than 400 academic programs through 13 schools and colleges to nearly 32,000 students. Its School of Medicine is the largest single-campus medical school in the nation with more than 1,200 medical students. In addition to undergraduate medical education, the school offers master’s degree, Ph.D. and M.D.-Ph.D. programs in 14 areas of basic science to about 400 students annually.
Contact: Julie O’Connor
Wayne State University - Office of the Vice President for Research