Serum Biomarkers Predict Women at Risk of Preeclampsia

The screening of pregnant women to identify those at risk of preeclampsia may improve the prognosis for the mother and the infant and accordingly, there has been an intense search for the early biomarkers of preeclampsia.

Severe preeclampsia can affect the mother by damaging the kidneys, liver and other organs and, in really severe cases, cause seizures and coma. There is often less fluid than normal around the baby and the placenta can be affected, restricting blood flow and nutrients necessary for the baby's growth.

Scientists at the Mexican Institute of Social Security (Mexico City, Mexico) carried out a longitudinal study on 252 pregnant women attending two obstetric referral hospitals. Women visited the hospital once a month until delivery. Fasting blood samples from a peripheral vein were obtained after a 10 hour fast and collected in anti-coagulation vacuum-sealed tubes. Clinical records were assessed after every visit to identify women diagnosed with preeclampsia by the obstetrician responsible for her care, which included systolic blood pressure and diastolic blood pressure measurements.

Biochemical determinations were conducted and asymmetric dimethylarginine (ADMA), homocysteine,(Hcy), and vitamin B6 (VB6) and measured by high-performance liquid chromatography (Waters 600, Milford, MA, USA) , with a fluorescence detector (Model 474) and 4.6 × 250-mm columns (ODS Hypersil, Keystone Scientific; Bellefonte, PA, USA). VB12 was measured by chemiluminescence using commercial kits on the Immulite1000 Systems (Siemens; Erlangen, Germany), and folic acid (FA) was measured in whole blood by the microbiological method.

The team found that of the 252 women in their study, based at two hospitals, 49 in the group who went on to develop preeclampsia had raised levels of ADMA and Hcy a month before onset of the condition. The levels of these two biomarkers were raised regardless of the eventual severity of the preeclampsia. There were no significant differences in the concentrations of Hcy and ADMA between the mild preeclampsia and the severe preeclampsia groups; however, the group with mild preeclampsia exhibited intermediate values between the groups with no complications and with severe preeclampsia. Analysis of deltas demonstrated that ADMA and Hcy increased by 124 ± 27 nmol and 1,177 ± 278 nmol respectively, at one month prior to preeclampsia and such increases did not differ between mild and severe preeclampsia groups.

Mardia Lopez-Alarcon, PhD, the lead author of the study said, “While for most of the women we tested the levels of ADMA and Hcy remained constant throughout pregnancy, these serum biomarkers were clearly raised a month before onset in women who went on to develop pre-eclampsia. Of the other factors we tested, obesity and low levels of folic acid at the start of the pregnancy, as all the mothers received folic acid supplementation, were also independently linked to preeclampsia.” The study was published on July 22, 2015, in the journal BJOG: An International Journal of Obstetrics and Gynaecology.

Related Links:
Mexican Institute of Social Security 
Waters
Siemens