Messenger RNA encoding thiol protein disulphide isomerase in amnion, chorion and placenta in human term and preterm labour

Objective To investigate levels of messenger RNA (mRNA) encoding thiol protein disulphide isomerase, in human amnion, chorion and placenta during pregnancy and in relation to term and preterm labour. Design Amnion, chorion and placenta from 33 women delivered between 24 and 41 weeks of gestation were used in the study. Setting Reproductive Molecular Research Group, Department of Obstetrics and Gynaecology, University of Cambridge Clinical School, Rosie Maternity Hospital, Cambridge. Results Women who were delivered spontaneously before 30 weeks of gestation had higher levels of mRNA encoding thiol protein disulphide isomerase in placenta and chorion than those who were delivered spontaneously after this time (placenta P < 0.01, chorion P < 0.01) and compared with those who were delivered by elective caesarean section before 30 weeks of gestation (placenta P < 0.001, chorion P < 0.05). In the group in whom spontaneous labour occurred, at all gestations studied, there were increased levels of mRNA encoding thiol protein disulphide isomerase in the placenta (P < 0.001) and chorion (P < 0.001) compared with the amnion. Conclusion Changes in the steady state level of mRNA encoding thiol protein disulphide isomerase may play a role in the onset of preterm labour before 30 weeks of gestation.