Pentraxin 3 (PTX3) and C-reactive protein (CRP) levels were measured in the first trimester of pregnancy in women who subsequently developed preeclampsia (PE, n=16) and fetal growth restriction (FGR, n=12) requiring iatrogenic delivery before 37 weeks, and those who had uncomplicated pregnancies delivering at term (n=60). Mean PTX3 levels were significantly higher in women who subsequently developed PE (7.31 ng/ml, SD = 4.12) when compared to those with normal pregnancy outcome (4.92 ng/ml, SD = 1.94, p=0.0046). There were no significant differences between PTX3 levels in women with FGR (4.82 ng/ml, SD = 2.35) compared to normal pregnancy outcome (p=0.88). The median CRP levels did not vary significantly between the three groups (p=0.26). PTX3 levels in women who subsequently develop PE are already elevated in the first trimester, but not in those that develop FGR. This supports the hypothesis of an excessive maternal inflammatory response to pregnancy in the etiology of PE.