Serum deoxycytidylate deaminase as an index of high-risk pregnancy

Serum deoxycytidylate deaminase (EC 3.5.4.12, dCMP deaminase) activity was routinely estimated over 7 years in 2460 pregnancies. The results confirm that elevated dCMP deaminase activity (greater than 4.8 units) is associated with the development of pre-eclampsia but not with essential hypertension in pregnancy; a high rising level can precede eclampsia. Elevated enzyme activity was also found in women who developed jaundice in pregnancy and in some with apparently normal pregnancies. An unexpected finding was that these so called 'false positive' high levels were associated with all the unexplained intrauterine fetal deaths that occurred later in pregnancy. Although elevated dCMP deaminase levels may be associated with a normal outcome, persisting high levels indicate the need for careful monitoring of fetal well being and, in the presence of any other sign of placental insufficiency, delivery should be expedited.