Vaginal progesterone reduces preterm birth and neonatal complications in women with a mid-trimester short cervix

Results of a major international study released today in the American Journal of Obstetrics & Gynecology

Philadelphia, November 17, 2017

Prematurity is the main complication of pregnancy, and 15 million babies are born preterm worldwide each year.

Progesterone is a natural hormone produced by the ovaries in early pregnancy, and then later by the placenta. A decline in progesterone action is implicated as one of the causes of spontaneous preterm labor and delivery. Physicians worldwide have investigated in many studies whether vaginal progesterone administration to women with a mid-trimester sonographic short cervix reduces the rate of preterm birth.

Most major studies have been positive, until the publication of a study in February 2016. Now physicians and researchers have summarized the results of all studies in an article published today in the American Journal of Obstetrics & Gynecology, and found that when all available information is considered in an individual patient data meta-analysis – the gold standard for summarizing clinical evidence – the results are clear.

Vaginal progesterone reduces the rate of preterm birth at <28, <30, <32, <34, <35, and <36 weeks. Moreover, it reduces the frequency of complications of prematurity and the number of babies weighing less than 1500 grams (also called very low birth weight).

The authors also reviewed cost-effectiveness studies, which showed that measuring the uterine cervix with ultrasound in the mid-trimester of pregnancy and giving vaginal progesterone to those with a short cervix is cost-effective (this strategy has been estimated to save the U.S. healthcare system approximately $500 million dollars per year). The researchers also reviewed the evidence of studies, which showed that when this approach is implemented in clinical practice, it reduces the rate of preterm birth in the “real world.”

“The findings of our meta-analysis of individual patient data, which includes all available trials, should reassure clinicians and professional/scientific organizations that vaginal progesterone is efficacious and safe for reducing preterm birth and neonatal morbidity and mortality in women with a sonographic short cervix,” commented Roberto Romero, MD, DMedSci, Chief of the Perinatology Research Branch, NICHD/ NIH/ DHHS, and Kypros Nicolaides, MD, professor and head of Obstetrics and Gynecology, Kings College, London, and head of the Fetal Medicine Foundation. “In addition, recent evidence assessing the implementation of universal cervical length screening in women with a singleton gestation and treatment with vaginal progesterone to those with a short cervix suggests that this intervention could contribute to a reduction in the rate of preterm birth and associated neonatal morbidity and mortality in the United States.”


Notes for Editors
The article is “Vaginal Progesterone for Preventing Preterm Birth and Adverse Perinatal Outcomes in Singleton Gestations with a Short Cervix: A Meta-Analysis of Individual Patient Data,” by Roberto Romero, MD, DMedSci, Agustin Conde-Agudelo, MD, MPH, PhD, Eduardo Da Fonseca, MD, John M. O’Brien, MD, Elcin Cetingoz, MD, George W. Creasy, MD, Sonia S. Hassan, MD, Kypros H. Nicolaides, MD ( It appears in the American Journal of Obstetrics & Gynecology published by Elsevier and is freely available.

Publication coincides with World Prematurity Day, November 17, 2017. A short video of this story is available at:, which contains images and a narrated video.

Full text of this article is available to credentialed journalists upon request. Contact Eileen Leahy at +1 732-238-3628 or to obtain copies. The authors may be reached at the following:

Roberto Romero, Detroit, MI (lead author), USA: +1 313-330-9978 or
Kypros Nicolaides, London, UK (senior author): +44 773-679-0311 or
Agustin Conde-Agudelo, Cali, Colombia: +57 301-694-4381 or
Eduardo Fonseca, Sao Paulo, Brazil: +55 839-9131-8677 or
Sonia Hassan, Detroit, Michigan, USA: +1 313-577-5774 or
John O'Brien, Lexington, Kentucky, USA: +1 859-221-2517 or
George Creasy, New York, NY, USA: +1 908-963-6494 or
Elcin Cetingoz, Istanbul, Turkey: +90 505-767-5716 or

This research was supported, in part, by the Perinatology Research Branch, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services.

About the American Journal of Obstetrics and Gynecology
The American Journal of Obstetrics and Gynecology, known as “The Gray Journal,” presents coverage of the entire spectrum of the field, from the newest diagnostic procedures to leading edge research. The Journal provides comprehensive coverage of the specialty, including maternal-fetal medicine, reproductive endocrinology/infertility, and gynecologic oncology. It also publishes the annual meeting papers of several of its eight sponsoring societies, including the Society for Maternal-Fetal Medicine and the Society of Gynecologic Surgeons. The journal has also been recognized as one of the 100 most influential journals in Biology & Medicine over the last 100 years, as determined by the BioMedical & Life Sciences Division of the Special Libraries Association (2009).

About Elsevier
Elsevier is a global information analytics business that helps scientists and clinicians to find new answers, reshape human knowledge, and tackle the most urgent human crises. For 140 years, we have partnered with the research world to curate and verify scientific knowledge. Today, we’re committed to bringing that rigor to a new generation of platforms. Elsevier provides digital solutions and tools in the areas of strategic research management, R&D performance, clinical decision support, and professional education; including ScienceDirect, Scopus, SciVal, ClinicalKey and Sherpath. Elsevier publishes over 2,500 digitized journals, including The Lancet and Cell, 39,000 e-book titles and many iconic reference works, including Gray's Anatomy. Elsevier is part of RELX, a global provider of information-based analytics and decision tools for professional and business customers.

Media contact
Eileen Leahy
+1 732-238-3628