Feb. 4, 2022 -- In the country with one of the highest rates of preterm birth in the world, these early deliveries dropped by 24% with a simple intervention: chewing a certain kind of gum during pregnancy.

The drop in preterm births was linked to the gum’s effect on improving oral health, according to research presented at a conference sponsored by the Society for Maternal-Fetal Medicine.

The findings come from a randomized controlled trial of women in the African nation of Malawi, where researchers also found the gum containing xylitol helped reduce the risk of gum disease, according to Kjersti Aagaard, MD, PhD, of Baylor College of Medicine and Texas Children’s Hospital.

“For a while, we have known about the association with poor oral health and preterm birth but I am not aware of a study of this magnitude suggesting a simple and effective treatment option,” said Ilina Pluym, MD, an assistant professor in maternal fetal medicine at UCLA, who attended the presentation.

Pluym called the new data “compelling” but said the study must be repeated, ideally in countries with lower rates of preterm birth and periodontal disease to see if the effect is similar, before broadly implementing this cheap and simple intervention.

Preterm birth is a leading cause of infant mortality and a major cause of health problems in children under 5 worldwide. As many as 42% of children born preterm have a related health condition or do not survive childhood.

About 1 in 5 babies in Malawi are born between 26 and 37 weeks. That is about double the U.S. rate of 10.8% preterm births. Researchers chose Malawi for the trial because residents there see preterm birth as a widespread problem that must be addressed, Aagaard said.

Previous studies have found a link between gum disease and deliveries that are preterm or low birth weight, Aagaard said. However, 11 randomized controlled trials that involved treating gum disease did not reduce preterm birth despite improving periodontitis and oral health.

Aagaard’s team decided to test the effectiveness of xylitol – a natural prebiotic found in fruits, vegetables, and bran – because harmful oral bacteria cannot metabolize the substance, and regular use of xylitol reduces the number of harmful mouth bacteria while increasing the number of good microbes in the mouth. Xylitol is found in many common brands of gum, including Mentos, Trident and Orbit.

In addition, a study in 2006 found that children up to 4 had fewer cavities and ear infections when their mothers chewed gum containing xylitol and other compounds. Aagaard said gums without xylitol do not appear to produce the same improvements in oral health.

Before beginning the trial, Aagaard’s group spent 3 years doing a “run-in” study to ensure a larger, longer-term trial in Malawi was feasible. That initial study found a reduction in tooth decay and periodontal inflammation with use of xylitol. The researchers also learned that participants preferred gum over lozenges or lollipops. Nearly all the participants (92%) chewed the gum twice daily.

Among 10,069 women who enrolled in the trial, 96% remained in it until the end. Of those, 4,029 took an oral health assessment at the start of the study, and 920 had a follow-up oral health assessment.

Of the 4,349 women who chewed xylitol gum, 12.6% gave birth before 37 weeks, compared with 16.5% preterm births among the 5,321 women in the control group – a 24% reduction. The 16.5% rate among women not chewing gum was still lower than the national rate of 19.6%, possibly related to the education the participants received, according to the researchers.

The groups showed no significant differences in stillbirths or newborn deaths.

The researchers did, however, find a significant drop in gum disease among the women who chewed xylitol gum and came for follow-up dental visits. The rate of periodontal disease dropped from 31% to 27% in those not chewing gum but from 31% to 21% in gum chewers.

“This cannot be attributed to overall oral health, as [tooth decay] composite scores did not significantly differ while periodontitis measures did,” Aagaard said.

Whether recommending xylitol chewing gum to pregnant women in other countries would affect rates of preterm birth is unclear. The ideal population for an intervention like this is one where the population has a high rate of gum disease or other preterm birth risk factors, Pluym said.

““A quick fix is not the solution for everyone,” she said.