Pregnancy loss occurs in about 20% of women with a clinically recognized pregnancy. One factor could be chronic inflammation caused by a change to the innate immune system after a sexually transmitted infection (STI), referred to as the trained innate immunity hypothesis. Anti-inflammatory aspirin therapy prior to conception has been shown to improve birth rates in some women with histories of pregnancy loss when they experience chronic low-grade inflammation prior to pregnancy. Researchers hope to learn more about factors that drive chronic preconception inflammation and pregnancy loss as they search for targeted therapies.

A new study by Brandie DePaoli Taylor, associate professor of epidemiology and biostatistics, seeks to determine whether a broader number of women could benefit from aspirin therapy by identifying new connections between STIs, preconception inflammation and pregnancy outcomes. Her four-year, $1.8 million study, funded by the National Institute of Allergy and Infectious Diseases, is reexamining biological samples from women who participated in a prior NICHD study called the EAGeR Trial (Effects of Aspirin in Gestation and Reproduction). 

“EAGeR found that aspirin doesn't seem to improve birth outcomes unless a woman has underlying inflammation,” Taylor says. In collaboration with EAGeR investigators, this study will measure evidence of exposure to STIs, inflammation and pregnancy loss. Second, the study will determine if women with evidence of STIs benefit from aspirin therapy.

STIs are often undiagnosed and asymptomatic, but evidence of infection is found in blood serum samples. Samples from women in the EAGeR trial will be sent for new analysis to the Statens Serum Institut in Denmark. Specific STIs will be investigated. It is known that chlamydia is associated with infertility, Taylor says, “but the data is inconsistent about whether it's associated with other measures of impaired fecundity or impaired fertility, like repeated spontaneous abortion. We also have an emerging infection called Mycoplasma genitalium, which is similar to chlamydia, but there's not enough known about the long-term implications to have any clear screening guidelines.”

The study could help establish whether prior exposure to these STIs impacts a woman's immunological profile prior to trying to become pregnant.  That could suggest potential use of aspirin therapy prior to pregnancy.

“When it comes to women who are having trouble getting pregnant, there are infertility clinics, but only about 18% of the population that has trouble becoming pregnant actually can seek those services,” Taylor says. “Aspirin therapy may be a relatively cheap and accessible way to improve birth outcomes.”