Serum arachidonic acid levels in normal and preeclamptic pregnancies.

Fifteen serum samples from 11 women with preeclampsia and 19 samples from 10 normal third-trimester pregnancies were analyzed for total nonesterified fatty acids and total nonesterified arachidonic acid. The percentages of arachidonic acid in nonesterified fatty acids, in phospholipids, in triglycerides, and in cholesterol esters were also measured in each sample. The same analyses were done on serum from six samples of cord blood from each group. Cord blood sera from preeclamptic and normal pregnancies had much less total nonesterified fatty acids than the corresponding maternal sera but had much higher percentages of arachidonic acid in each of the major lipid categories. The maternal phospholipids and cholesterol esters had higher proportions of arachidonic acid in preeclampsia than in normal pregnancy. Samples from placentas of preeclamptic pregnancies had significantly lower proportions of arachidonic acid in the nonesterified fatty acids and triglycerides than normal placentas. These findings suggest a decreased availability of arachidonic acid in the fetal circulation which may result in decreased production of prostacyclin in preeclampsia.