Understanding the mechanisms of human tubal ectopic pregnancies: new evidence from knockout mouse models

Ectopic pregnancy, a worldwide health problem, is potentially life-threatening and occurs in approximately 1.5–2% of all pregnancies in the western world; however, the precise mechanisms underlying the initiation and development of tubal ectopic pregnancy are unknown. Tubal abnormalities and dysfunction, such as altered contractility or abnormal ciliary activity, have been speculated to lead to tubal ectopic pregnancy. To elucidate the cellular and molecular mechanisms of the tubal transport process, several knockout (KO) mouse models have been developed. This review summarizes what has been learned from studies of the Fallopian tube in caspase-1, cannabinoid receptor and Dicer1 KO mice. Our understanding of the mechanisms which contribute to tubal ectopic pregnancy in humans may be enhanced through further study of these KO mouse models.