Can probiotics cut the number of preterm births?
A new study suggests that probiotics supplementation during early pregnancy may help reduce the risk of recurrent spontaneous preterm delivery (sPTD). In a multicentre clinical trial, pregnant women who consumed probiotics containing Clostridium butyricum showed lower recurrence rates of sPTD compared with national averages. These findings highlight the potential of certain probiotic therapies as a strategy to support healthier pregnancy outcomes, according to the authors of the paper published in the American Journal of Obstetrics and Gynecology.
Babies born prematurely face increased risks of complications such as respiratory distress, infections, neurological injury, and long-term developmental disabilities. Women with a history of sPTD are particularly vulnerable, as the condition often recurs in subsequent pregnancies. Therefore, preventing preterm birth in these high-risk cases remains a significant challenge in obstetric medicine.
To investigate the impact of probiotics on sPTD, the researchers conducted a prospective multicentre clinical trial across 31 hospitals in Japan between 2021 and 2024. The study enrolled pregnant women aged 18 to 43 years who had previously experienced sPTD, placing them at elevated risk for recurrence. Participants between 10 and 14 weeks of pregnancy received oral probiotic tablets and continued supplementation until a later phase of pregnancy (36 weeks and 6 days of gestation). Each tablet contained 10 mg of C. butyricum, 2 mg of Enterococcus faecium, and 10 mg of Bacillus subtilis and was taken three times daily throughout the study period.
Among the 315 participants, the recurrence rate of sPTD before 37 weeks was 14.9%, which was significantly lower than the 22.3% recurrence rate reported in Japan’s national perinatal database. These findings suggest that probiotic supplementation may help reduce the likelihood of premature birth in women with a prior history of the condition. Encouraging outcomes were also observed for earlier and more severe cases of preterm birth. The total percentage of sPTD was reduced significantly. Importantly, the probiotic regimen showed a favourable safety profile, and no serious adverse events related to the treatment were reported.
The researchers also analysed changes in the participants’ intestinal microbiota during pregnancy. In women who delivered at term, the proportion of Clostridium species in the gut increased approximately five-fold after probiotic supplementation. However, this increase was not observed among women who experienced recurrent preterm delivery.
‘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,’ explains Dr Satoshi Yoneda, Department of Obstetrics and Gynecology, University of Toyama, Japan.
The authors suggest that future studies are necessary to confirm the effectiveness of probiotic therapy in preventing recurrent sPTD. Overall, this study highlights the potential of probiotics supplementation to help reduce the risk of recurrent sPTD and improve outcomes for mothers and infants.
