Nav: Home

Common tests for preterm birth not useful for routine screening of first-time pregnancies

March 14, 2017

Two methods thought to hold promise in predicting preterm delivery in first-time pregnancies identified only a small proportion of cases and do not appear suitable for widespread screening, according to a large study by a National Institutes of Health research network.

The study focused on spontaneous preterm delivery -- labor that occurs naturally -- rather than delivery initiated for medical need, such as cesarean surgery or induced labor.

The study authors evaluated routine ultrasound examination of the uterine cervix, the lower part of the uterus that shortens and opens during labor. Previous studies have indicated that a short cervix early in pregnancy could be a warning sign of impending preterm birth. The researchers also evaluated testing for fetal fibronectin, a glue-like protein that secures the amniotic sac to the inside of the uterus. Some studies have suggested that the presence of fetal fibronectin in the vagina early in pregnancy could signal early labor.

However, after screening more than 9,000 women throughout pregnancy, each test identified only a small proportion of the women who would eventually deliver preterm.

"These methods of assessing women in their first pregnancy do not identify most of those who will later go on to have a spontaneous preterm delivery," said the study's senior author, Uma Reddy, M.D., of the Pregnancy and Perinatology Branch at NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development. "There is a need to develop better screening tests that can be performed early in pregnancy."

The article appears in the Journal of the American Medical Association.

The study included 9,410 women pregnant with a single fetus at eight research centers in the United States. It was conducted as part of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b), which aims to improve the care of women during their first pregnancy and to find new ways to identify impending preterm birth and other adverse pregnancy conditions.

The women underwent ultrasound testing to measure cervical length at 16 to 22 weeks of pregnancy and again from 22 to 31 weeks of pregnancy. Fetal fibronectin tests were conducted at 6 to 14 weeks, 16 to 22 weeks and 22 to 30 weeks. A short cervix was defined as less than 25 mm.

Of the women tested at 16 to 22 weeks, 35 of 439 women (8 percent) who delivered spontaneously before the 37th week of pregnancy had a short cervix. At 22 to 31 weeks, 94 of 403 women (23.3 percent) who delivered prematurely had a short cervix.

For the fibronectin test at 16 to 22 weeks, 30 of 410 women (7.3 percent) who delivered spontaneously before the 37th week had high fibronectin levels. At 22 to 30 weeks, 31 of 384 women (8.1 percent) who delivered prematurely had high fibronectin levels. The authors defined a high fibronectin level as 50 ng/mL or greater.

The researchers found no benefit to combining the results of the two tests. They concluded that, alone and together, the methods did not identify enough preterm births to support routine screening of first-time pregnancies.
-end-
REFERENCE: Esplin, MS, et al. Predictive accuracy of serial transvaginal cervical length by ultrasound and quantitative vaginal fetal fibronectin for spontaneous preterm birth among nulliparous women. JAMA. 2017:317(10)1-10. Doi:10.1001/jama.2017.1373.

About the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD): NICHD conducts and supports research in the United States and throughout the world on fetal, infant and child development; maternal, child and family health; reproductive biology and population issues; and medical rehabilitation. For more information, visit NICHD's website.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.

NIH/Eunice Kennedy Shriver National Institute of Child Health and Human Development

Related Pregnancy Articles:

Are women using e-cigarettes during preconception and/or pregnancy?
A new study of 1,365 racially/ethnically diverse, low-income pregnant women found that 4% reported e-cigarette use.
A better pregnancy test for whales
To determine whale pregnancy, researchers have relied on visual cues or hormone tests of blubber collected via darts, but the results were often inconclusive.
Cannabis use during pregnancy
The large health care system Kaiser Permanente Northern California provides universal screening for prenatal cannabis use in women during pregnancy by self-report and urine toxicology testing.
Questions and answers about cannabis use during pregnancy
A new study shows that women have many medical questions about the use of cannabis both before and during pregnancy, and during the postpartum period while breastfeeding.
The effect of taking antidepressants during pregnancy
Exposure to antidepressants during pregnancy and the first weeks of life can alter sensory processing well into adulthood, according to research in mice recently published in eNeuro.
Is ivermectin safe during pregnancy?
Is it safe to give ivermectin to pregnant women? To answer this question, researchers from the Barcelona Institute for Global Health (ISGlobal), an institution supported by 'la Caixa,' conducted a systematic review and meta-analysis of studies that reported cases of accidental exposure to the drug among pregnant women.
Going to sleep on your back in late pregnancy
This study looked at whether going to sleep on your back in the third trimester of pregnancy was associated with average lower birth weights.
Opioid use disorder in pregnancy: 5 things to know
Opioid use is increasing in pregnancy as well as the general population.
Medical imaging rates during pregnancy
Researchers looked at rates of medical imaging (CT, MRI, conventional x-rays, angiography, fluoroscopy and nuclear medicine) during pregnancy in this observational study that included nearly 3.5 million pregnant women in the United States and Canada from 1996 to 2016.
New research on diet and supplements during pregnancy and beyond
The foods and nutrients a woman consumes while pregnant have important health implications for her and her baby.
More Pregnancy News and Pregnancy Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Clint Smith
The killing of George Floyd by a police officer has sparked massive protests nationwide. This hour, writer and scholar Clint Smith reflects on this moment, through conversation, letters, and poetry.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.