Increases in two biomarkers – asymmetric dimethylarginine (ADMA) and homocysteine – could detect women at high risk of developing pre-eclampsia.

This is according to a study in which ADMA, homocysteine, vitamins B6, B12 and folic acid were measured every month from 20 weeks or less of gestation until delivery in 252 women. ADMA is an endogenous inhibitor of nitric oxide synthase. This generates nitric oxide, an important vasoprotective molecule.

Increases in homocysteine indicate raised levels of free radicals and endothelial damage. Ten and 39 women developed mild and severe pre-eclampsia respectively.
The authors excluded 24 women who experienced other pregnancy complications.

Levels of ADMA and homocysteine increased gradually during pregnancy in women who developed pre-eclampsia, but remained constant in women without complications. Increases of at least 80 nmol ADMA and 1,000nmol homocysteine were associated with a 3.25 and 3.93 fold increase in pre-eclampsia risk in the next month respectively.

The increases in the biomarkers were independent of B vitamin status, suggesting that the changes are unrelated to vitamin deficiency, and of obesity, a well-characterised pre-eclampsia risk factor. (BJOG doi:10.1111/1471-0528.13516).