Conclusions
There was no significant association between IFNε and spontaneous preterm birth (ORadj 1.0, 0.8-1.3) or chorioamnionitis (ORadj 1.6, 0.7-3.5). A trend toward increased odds of medically indicated preterm birth (ORadj . 1.3, 1.0-1.8) was observed. This was likely due to elevated IFNε among women with preterm preeclampsia (ORadj . 2.0, 95% CI 1.3-3.2). While exploratory, our novel findings suggest that larger longitudinal studies of IFNε across human pregnancy may be warranted.