Changes in the expression of the type-2 but not the type-1 cyclo-oxygenase enzyme in chorion-decidua with the onset of labour

Br J Obstet Gynaecol. 1998 Jul;105(7):745-8. doi: 10.1111/j.1471-0528.1998.tb10205.x.


Objective: To determine the relative expression of cyclo-oxygenase (COX)-1 and COX-2 in the chorion-decidual part of human fetal membranes following delivery at term and to identify any changes in expression associated with labour.

Methods: Fetal membranes were collected from 12 term pregnancies before labour following elective caesarean section and from 12 spontaneous vaginal deliveries. Expression of COX-1 and COX-2 mRNA was measured using a previously validated quantitative RT-PCR assay.

Results: COX-2 expression exceeded that of COX-1 by approximately eight-fold. COX-1 expression did not change but COX-2 expression was found to increase four-fold with labour.

Conclusions: Chorion-decidua has the capacity to contribute to the increase in prostaglandin synthesis within the uterus associated with labour. As in the amnion, it is COX-2 and not COX-1 which is upregulated with labour. COX-2 selective anti-prostaglandins should therefore be as effective as nonselective drugs in inhibition of fetal membrane prostaglandin synthesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cesarean Section
  • Chorion / enzymology*
  • Decidua / enzymology*
  • Female
  • Humans
  • Isoenzymes / metabolism*
  • Labor, Obstetric / metabolism*
  • Polymerase Chain Reaction / methods
  • Pregnancy
  • Prostaglandin-Endoperoxide Synthases / metabolism*
  • RNA, Messenger / metabolism


  • Isoenzymes
  • RNA, Messenger
  • Prostaglandin-Endoperoxide Synthases