Maternal serum protein S forms in pregnancies complicated by intrauterine growth restriction

Abstract Objectives The clinical relevance of protein S deficiency in pregnant women remains controversial. Major debate exists regarding which parameter (total protein S antigen, free protein S antigen or functional protein S) should be evaluated in order to define protein S deficiency. The present study aimed to identify which of these parameters correlate with intrauterine growth restriction (IUGR). Study design A retrospective case–control study of women with IUGR ( n  = 27) and healthy controls ( n  = 123) in the third trimester of pregnancy. Results The maternal serum of women in the IUGR group had significantly lower levels of functional and free protein S compared with the control group: 54.07 ± 24.72% vs 65.20 ± 17.95% ( p p Conclusions Levels of functional and free protein S are correlated with IUGR.