Recurrent abortion.

A women who has experienced 3 or more consecutive abortions without ever maintaining a pregnancy to term, can be defined as a recurrent aborter, if there has been no therapeutic intervention of the pregnancies. A full clinical history may reveal the cause of an abortion and if corrected, allow subsequent pregnancies to proceed to term. The causes of recurrent abortion have not been fully identified however, and it is this group of patients, with abortions of unknown aetiology, that have been selected for investigation, Recurrent abortion represents approximately 1% of all pregnancies, consequently the number of patients to be examined is small. The study is justified when the reasons proposed for recurrent abortion of unknown aetiology are considered: Unlike organ transplants, a normally progressing pregnancy does not experience the problems associated with immunological rejection although paternal antigens foreign to the mother are present. In recurrent abortions therefore, one may be examining a defective immunological mechanism associated with pregnancy. Any conclusions reached, could have implications beyond those of pregnancy. A review of biochemical investigation reveals the importance of steroid hormones during gestation. Adequate levels of progesterone at critical periods in early pregnancy may directly dictate the success or failure of a pregnancy to reach term. The function of cytochromes in steroid biosynthesis and the existence of cytochrome P-448 in the placenta is of particular interest as this cytochrome predominates also in cancer cells. The localisation, function and period in which it can be detected in the placenta may collectively provide information regarding the cellular function of cancer cells. The physiological function of several cell types (decidua, placental bed giant cells, endometrial granulocytes) is at present largely unknown and, morphological investigation has limitations in resolving this area of research without the support of biochemical and immunological techniques. This thesis is concerned therefore, in exploring some of these avenues of investigation within the resources available