Changes of lipocalin-type prostaglandin D synthase level during pregnancy

Aim: Prostaglandin D (PGD), synthesized by lipocalin‐type prostaglandin D synthase (L‐PGDS), has marked effects on a number of biological processes, including the prevention of platelet aggregation and the relaxation of vascular smooth muscle. The aim of the study presented here was to examine the significance of L‐PGDS in human pregnancy. Methods: We measured the concentration of plasma L‐PGDS in pregnant and non‐pregnant women, and the concentration of L‐PGDS in the umbilical cord blood, amniotic fluid and urine of newborns by enzyme‐linked immunoabsorbent assay. To determine the localization of L‐PGDS, we performed immunohistochemical analysis. To evaluate the usefulness of diagnosis of rupture of membranes (ROM), we determined the concentration of L‐PGDS in cervicovaginal secretions. Results: Pregnant women and non‐pregnant women had similar L‐PGDS concentrations (0.57 ± 0.13 µg/mL vs 0.53 ± 0.07 µg/mL). Umbilical cord blood, amniotic fluid and newborn urine contained higher L‐PGDS concentrations (1.87 ± 0.73 µg/mL, 2.62 ± 0.86 µg/mL, 6.31 ± 4.62 µg/mL, respectively) than maternal blood. The concentration of L‐PGDS in amniotic fluid from 19 weeks onward was significantly greater than that at 15–18 weeks (3.201 ± 0.384 µg/mL, n = 6 vs 1.735 ± 0.477 µg/mL, n = 4; P