Mechanisms regulating prostaglandin H2 synthase-2 mRNA level in the amnion and chorion during pregnancy

Increasing prostaglandin H2 synthase (PGHS)-2 expres-sion in the fetal membranes is implicated in the produc-tion of prostaglandins (PGs) that stimulate labour. We have determined the activity of the PGHS-2 gene in the amnion and chorion throughout gestation and defined the contribution of transcriptional and post-transcriptional mechanisms to the increase of PGHS-2 mRNA levels. We also measured PGHS-1 mRNA abundance to assess the participation of the two isoenzymes in fetal membrane PG-production during pregnancy. Amnion and chorion were collected from non-labouring women at 10–19 weeks (early), at 28–36 weeks (preterm) and at term (37–41 weeks). We determined PGHS-1 and-2 mRNA abundance and assessed PGHS-2 gene activity by measur