Activity of adenosine deaminase in mothers who have conceived a fetus with central nervous system malformations.

OBJECTIVE To establish the adenosine deaminase (ADA) activity in women who had been pregnant with a child suffering from central nervous system (CNS) anomaly. METHODS The study group comprised 68 women who had been pregnant with an affected child, and 68 controls matched for age, gestational age and body mass index. Maternal venous blood was collected for measurement of ADA levels. We defined the diagnostic sensitivity, specificity and area under receiver-operating characteristic curve for ADA. RESULTS Plasma ADA activity was significantly higher in the study group (12.3 U/L, range 1.7-33.3) compared to the median value of 3.3 U/L (range 1.1-34.4) in normal pregnancies (P<0.05). The cut-off point of ADA >5.9 U/L was associated with the highest combination of specificity (58.8%) and sensitivity (86.8%). CONCLUSION ADA activity in women who have conceived a fetus with CNS malformations was significantly higher than that in normal pregnant women.