Maternal serum diamine oxidase in fetal death and low-birth-weight infants.

Serum diamine oxidase was measured at different gestational ages in 681 pregnancies resulting in live births and 102 pregnancies resulting in fetal deaths. Statistical analysis revealed that gestational age-adjusted diamine oxidase levels in the fetal-death group were significantly lower (P less than 0.001) than those in the live-birth group. Moreover, the relative risk associated with a low diamine oxidase level, compared with a normal level, increased from 3.7 at 8 weeks to 16.6 at 12 weeks. Pregnancies resulting in low-birth-weight infants exhibited normal serum diamine oxidase levels. The association between low diamine oxidase and subsequent fetal death is discussed in view of the hypothesis that polyamines and polyamine-degrading enzymes interact to protect the fetoplacental unit from immune rejection.