Azathioprine in Pregnancy
Research type
Research Study
Full title
Intrauterine exposure to conventional thiopurine therapy and neonatal anaemia
IRAS ID
138675
Contact name
Catherine Nelson-Piercy
Contact email
Sponsor organisation
Guy's and St Thomas's NHS Foundation Trust
Duration of Study in the UK
3 years, 0 months, 1 days
Research summary
Azathioprine is the principle thiopurine immune modifying drug used in the UK for the management of inflammatory bowel disease, organ transplantation, systemic lupus and interstitial lung disease. Patients with these conditions are often in their reproductive years. Azathioprine has a good safety profile in pregnancy. Treatment with azathioprine is therefore continued during pregnancy to prevent disease relapse and/or transplant rejection. Currently, infants born to mothers taking azathioprine in pregnancy do not routinely have their haemoglobin level measured.
In 2013, a prospective cohort study was published which examined intrauterine exposure to thiopurine therapy in pregnant patients. Cord blood from 25 infants showed that the fetus is exposed to active thiopurine metabolites in utero. Haemoglobin was measured in 16 infants of whom 10 were diagnosed with anaemia. However, the median haemoglobon of the babies diagnosed with anaemia was within the 95% reference range for term neonatal haemoglobin. In addition, although the diagnosis of neonatal anaemia was associated with a higher mean thiopurine metabolite concentration, this correlation was not statistically significant. The authors of the study recommended that all infants exposed to thiopurines in pregnancy be examined for anaemia.
The aim of this study is to measure haemoglobin from either cord blood or blood taken at time of the Guthrie test in infants whose mothers were exposed to azathioprine in pregnancy to determine whether neonates exposed to azathioprine in prgenancy are anaemic.
Maternal anaemia, renal function, inflammatory response and sepsis can all potentially affect the neonatal haemoglobin measurement. Blood taken routinely during pregnancy will be examined for the presence of these possible confounding factors.
REC name
London - South East Research Ethics Committee
REC reference
14/LO/1935
Date of REC Opinion
8 Jan 2015
REC opinion
Further Information Favourable Opinion