Molecular mechanisms of tubal pregnancy

Ectopic pregnancy is common and is still associated with significant morbidity and mortality, despite advances in diagnosis and treatment. Most of the consequences are related to either late or missed diagnosis. Despite these consequences, a reliable biomarker is yet to be developed. Although the classical risk factors include pelvic inflammatory disease, smoking, tubal surgery, previous ectopic pregnancy and tubal disease, a significant number of ectopic pregnancies occur in women without risk factors. This article aims to elaborate on the understanding of the molecular biology of ectopic pregnancy by discussing the role of interleukins, mucins, activins, VEGF, prokineticins, integrins, inducible nitric oxide synthase, cysteine-rich secretory protein 3 and endocannabinoids in the pathophysiology of tubal pregnancy. Such an understanding of the molecular/biological basis and etiopathogenesis may ultimately lead to the development of a reliable biomarker for diagnosis.