Serial determinations of asymmetric dimethylarginine and homocysteine during pregnancy to predict pre‐eclampsia: a longitudinal study

OBJECTIVE: To evaluate the usefulness of serial determinations of asymmetric dimethylarginine (ADMA) and homocysteine (Hcy) concentrations during pregnancy to predict pre-eclampsia, taking into account maternal obesity and B vitamin status. DESIGN: Longitudinal study. SETTING: Two obstetric referral hospitals. SAMPLE: Two hundred and fifty-two of 411 women invited to participate in the study. METHODS: The women made monthly visits from ≤20 weeks of gestation until delivery for measurements of plasma ADMA, Hcy, and vitamins B6 , B12, and folic acid, and for the recording of clinical information. MAIN OUTCOME MEASURE: Early elevations in plasma ADMA and Hcy related to the development of pre-eclampsia. RESULTS: Of the 252 women who completed the study, 179 had no complications, 49 developed pre-eclampsia, and 24 presented with complications other than pre-eclampsia. ADMA and Hcy increased gradually throughout pregnancy in the pre-eclampsia group, independent of maternal B-vitamin status and obesity, but remained constant in women with no complications. Relative to the preceding month, ADMA and Hcy levels increased 1 month prior to the onset of pre-eclampsia: 124 ± 27 nmol (P < 0.001) and 1177 ± 278 nmol (P = 0.001), respectively, in the pre-eclampsia group. The group of women with no complications did not show any significant changes. Increases of 80 nmol ADMA and 1000 nmol Hcy at 1 month prior to the onset of pre-eclampsia demonstrated the best potential for prediction. CONCLUSIONS: Increased ADMA and Hcy levels precede clinical manifestations of pre-eclampsia. Therefore, serial determinations of their concentrations may be helpful in identifying women at risk. TWEETABLE ABSTRACT: Increased ADMA and Hcy precede clinical pre-eclampsia and may identify women at risk.