Probiotics In Early Pregnancy May Help Reduce Preterm Birth Risk: Study

At a time when India continues to grapple with a high burden of preterm births, a new international study has offered a potentially simple and cost-effective approach—probiotic supplementation during early pregnancy—to reduce the risk of recurrent spontaneous preterm delivery (sPTD).

Published in the American Journal of Obstetrics and Gynecology, the findings assume particular relevance for India, which accounts for one of the largest shares of preterm births globally. Preterm delivery—defined as birth before 37 weeks of gestation—remains a leading cause of neonatal mortality and long-term disability in the country.

Infants born prematurely often face serious health challenges, including respiratory distress, infections, impaired neurological development, and lifelong disabilities. For women with a history of spontaneous preterm delivery, the risk of recurrence is significantly higher, making prevention a critical priority in maternal healthcare.

The study, “Prevention of recurrent spontaneous preterm delivery using probiotics: results from a prospective, single-arm, multicenter trial,” conducted by researchers at the University of Toyama in Japan, examined whether probiotics could help address this risk. In a multicenter clinical trial involving 315 high-risk pregnant women, those who received probiotic supplementation early in pregnancy showed a markedly lower recurrence rate of preterm birth compared to national averages.

The probiotic formulation included Clostridium butyricum, known for its role in promoting beneficial gut bacteria and regulating immune responses. Participants who delivered at term showed a significant increase in these bacteria, suggesting a strong link between gut health and pregnancy outcomes.

“This study was motivated by our desire to reduce the number of children who develop long-term disabilities, especially those born extremely preterm, through appropriate obstetric interventions,” said lead author Associate Professor Satoshi Yoneda from the Department of Obstetrics and Gynecology, University of Toyama, Japan.

The study was co-authored by Dr. Shigeru Saito, also from the University of Toyama, and involved collaboration with multiple institutions across Japan.

The science behind this approach lies in the interaction between the gut microbiome and the maternal immune system. A healthy pregnancy requires a finely tuned immune balance—one that protects against infections while tolerating the developing fetus. Regulatory T cells, which help control inflammation, play a central role in this process, and certain gut microbes are known to support their function.

“Probiotics containing butyrate-producing bacteria initiated in early pregnancy may help prevent preterm delivery in women with a history of or at high risk for sPTD,” explained Dr. Yoneda.

However, the authors suggested that future studies are necessary to confirm the effectiveness of probiotic therapy in preventing recurrent sPTD. Overall, this study highlights the potential of probiotic supplementation to help reduce the risk of recurrent sPTD and improve outcomes for mothers and infants.

Public health experts point out that interventions that are safe, affordable, and easy to administer—such as probiotics—could be valuable additions to existing maternal health programs. However, they caution that such approaches must be supported by evidence generated within the Indian population.

Experts emphasize that while the findings are promising, India needs large-scale, population-specific studies before probiotics can be routinely recommended in antenatal care. Differences in diet, microbiome composition, socioeconomic conditions, and healthcare access mean that global findings cannot always be directly applied to Indian settings.

According to recent UNICEF estimates, a baby is born too early every two seconds across the world. One of these babies dies every 40 seconds, suggesting how serious the problem of preterm birth has become.

In India, the burden is especially high. Nearly one-fourth of global deaths linked to preterm births occur in India. Out of around 27 million births each year, about 3.6 million are estimated to be preterm.

Health experts say preterm birth is a complex issue. It is not caused by one single factor. Genetics, poor nutrition, infections, environmental exposure, and social conditions can play a major role.