Characterising Pregnancies Complicated by CHI
Research type
Research Study
Full title
Characterising Pregnancies Complicated by Chronic Histiocytic Intervillositis (CHI)
IRAS ID
315207
Contact name
Alexander E P Heazell
Contact email
Sponsor organisation
University of Manchester
Duration of Study in the UK
4 years, 11 months, 31 days
Research summary
The placenta, the organ which supplies the developing fetus with oxygen and nutrients during pregnancy, is made up of half of the mother’s genes and half of the father’s. Normally, a foreign organ (like a transplant) would trigger the mother’s immune system, however in a healthy pregnancy the placenta is protected. In a condition known as chronic histiocytic intervillositis (CHI), this protection appears to fail, and the mother’s immune cells build up in the placenta, preventing the growth of the baby, or in severe cases causing fetal death. During the recent COVID-19 pandemic, CHI was also found in some placentas from stillbirths where the mother had been infected with the virus.
Currently, CHI can only be diagnosed by specialist doctors who examine the placenta under a microscope after a pregnancy has been affected, and there are no treatments proven to prevent it. The cause of CHI is unknown, though it has been suggested that the mother’s immune system reacts inappropriately towards the semi-foreign placenta. CHI is rare (0.17% of all pregnancies), but returns in 25-100% of future pregnancies.
This study, funded by Tommy’s Baby Charity, aims to investigate the behaviour of the mother’s immune cells in CHI by collecting blood and placental samples from women with the condition attending Saint Mary’s Hospital, Manchester, UK over a period of five years. Participant questionnaires and medical records will also be used to identify possible risk factors associated with the development of CHI, for example change in paternity or autoimmune disease. By better understanding the cause of CHI and how immune cells cause poor outcomes, more specific treatments may be developed in future to increase the chance that women will go on to have a healthy baby after their first diagnosis. Investigation of potential markers in the blood of affected women may also allow those at risk of developing CHI to be identified before they suffer a pregnancy loss.REC name
North West - Preston Research Ethics Committee
REC reference
23/NW/0331
Date of REC Opinion
3 Nov 2023
REC opinion
Favourable Opinion