Should Pregnant Women Take Probiotics to Prevent Preterm Birth?

Recently, an article in JAMA about a potential relationship between the vaginal microbiome and preterm birth caught my attention.  According to the CDC, the statistics about preterm birth in the US are not good-  one in nine infants born in 2012 was premature. 

Factors associated with preterm birth include Black race, low socioeconomic status, urinary or vaginal infection, prior preterm birth, carrying more than 1 baby, high blood pressure, tobacco and alcohol use, and substance abuse.  But could the microbial environment of the vagina be a contributing factor?  The relationship between various human microbiomes and health or disease is a hot topic these days!

 A study of 49 women at Stanford University found that almost 2/3 of vaginal samples from women who delivered prematurely were Lactobacillus-poor.  Of women who carried to term, ¾ had Lactobacillus- dominant vaginal flora.  Although these findings contradict an earlier study, there were differences in study populations and definitions.  For example, the earlier study enrolled mainly African American women (known to have more diverse vaginal flora) and defined prematurity as birth prior to 34 weeks of gestation whereas the Stanford study evaluated primary white women and defined prematurity as birth occurring before 37 weeks. 

Clearly, more studies are needed to determine if a woman’s vaginal microbiome during pregnancy plays a significant role in preterm birth and whether there are any interactions between the microbiome and other factors such as obesity, inflammation and host genetics before recommending probiotics. 

                                                                                                                                       Judith Wolf,  MD                                                                                                                          Associate Director, WHEP

For more information:

Jacob JA.  Another Frontier in Microbiome Research: Preterm Birth.  JAMA 2015; 314:1550-1551.     DiGiulio DB et al.  Proc Natl Acad Sci USA 2015; 112:11060-11065    Romero R et al.  Microbiome 2014; 2:18    Fettweis JM et al.  Microbiology 2014; 160:2272-2282.