Immunohistochemical characterisation of trophoblast antigens and secretory products in ectopic tubal pregnancy.

Fetal trophoblast populations in ectopic fallopian tube pregnancy have been characterised using immunohistochemical techniques. The distribution of trophoblast membrane antigens, low molecular weight epithelial cytokeratins, epithelial membrane antigen, human chorionic gonadotrophin, human placental lactogen, and pregnancy-specific beta 1-glycoprotein in ectopic tubal pregnancy appears similar to that reported in normal early intrauterine pregnancy. These findings emphasise the potential importance of ectopic pregnancy in the study of human gestation.