To determine whether the midtrimester serum lipid profile, as expressed by fluorescence polarization (FP) values, is decreased in patients who subsequently develop pregnancy-induced hypertension (PIH). Stored serum samples of normotensive patients who had undergone midtrimester biochemical screening for Down's syndrome were used in this case-control study. Forty patients who subsequently developed PIH comprised the study group, and were divided into subgroups with proteinuric PIH (P-PIH, n = 18) and those with nonproteinuric PIH (NP-PIH, n = 22). Sixty randomly selected patients who remained normotensive throughout pregnancy comprised the control. Serum total cholesterol (CL) and triglycerides (TG) were determined using enzymatic colorimetric kits. FP values were determined by optical microviscosimeter. Both study subgroups had significantly lower FP values and higher TG concentrations than the control group. Total CL concentrations were slightly higher in the P-PIH subgroup. There were no differences in mean. Total CL or TG concentrations or mean FP values were found between those patients who developed mild and severe PIH. Using FP value cutoff points of 0.250, 0.245, and 0.240 sensitivity was 95%, 90%, and 78%, respectively, in detecting patients who subsequently developed PIH. Midtrimester serum FP values may have some predictive value for the development of P- and NP-PIH.