Does the Immune System Induce Labor? Lessons from Preterm Deliveries in Women with Autoimmune Diseases

A recent review of the literature suggested that thyroid autoimmunity is statistically associated with preterm delivery. This observation raises a number of follow-up questions, among them whether autoimmune function, in general, predisposes to premature delivery. A review of the English literature for the last 10 years, via PubMed search, finds strong supportive evidence for such a hypothesis. Since the fetal–placental unit represents a (semi) allograft within a maternal (allograft) recipient, it is reasonable to assume that it is subject to similar immunologic tolerance (and failure thereof) as solid organ transplants. As autoimmune responses represent a normal feature of tolerance failure in organ transplantation, similar autoimmune responses can also be expected with failure of tolerance of the fetal–maternal graft. The association of premature (and possibly also term) labor with autoimmune function may, therefore, be the consequence of abnormalities in normal fetal–placental tolerance, leading to uterine activation and labor.