{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,30]],"date-time":"2026-10-30T23:13:12Z","timestamp":1793401992388,"version":"4.5.0"},"reference-count":34,"publisher":"BMJ","issue":"3","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["Gut"],"accepted":{"date-parts":[[2013,1,28]]},"published-print":{"date-parts":[[2014,3]]},"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>Several studies have demonstrated a favourable safety profile for thiopurine use for inflammatory bowel disease (IBD) during pregnancy. We performed a study in pregnant patients with IBD who were using thiopurines, in order to determine the influence of pregnancy on thiopurine metabolism and to assess intrauterine exposure of the fetus to thiopurines.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design<\/jats:title>\n                    <jats:p>Female patients with IBD receiving steady-state thiopurines and planning a pregnancy were prospectively enrolled. 6-Thioguanine nucleotide (6-TGN) and 6-methylmercaptopurine (6-MMP) concentrations were determined, combined with routine laboratory tests, before, during and after pregnancy. Thiopurine metabolites were measured in umbilical cord blood immediately after delivery.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Thirty patients who were using azathioprine (28 patients, median dose 1.93\u2005mg\/kg) or mercaptopurine (two patients, doses 1.32 and 0.94\u2005mg\/kg) were included. During pregnancy, median 6-TGN decreased over time (p=0.001). while 6-MMP increased, without causing myelotoxicity or hepatotoxicity. After delivery, both 6-TGN and 6-MMP levels returned to preconception baseline levels. Fetal 6-TGN concentrations correlated positively with maternal 6-TGN levels (p&lt;0.0001). No 6-MMP was detected in the newborns, except one born with pancytopenia and high alkaline phosphatase activity; the mother of this infant had severe pre-eclampsia. All infants had normal Apgar scores, but 60% had anaemia at birth. No major congenital abnormalities were observed.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Pregnancy has a major effect on maternal thiopurine metabolism. In utero the unborn child is exposed to 6-TGN, but not to 6-MMP. Sixty per cent of the infants were born with anaemia, which raises the question whether infants should be tested for possible anaemia immediately after birth.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/gutjnl-2012-303615","type":"journal-article","created":{"date-parts":[[2013,2,20]],"date-time":"2013-02-20T00:50:10Z","timestamp":1361321410000},"page":"451-457","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":124,"title":["Intrauterine exposure and pharmacology of conventional thiopurine therapy in pregnant patients with inflammatory bowel disease"],"prefix":"10.1136","volume":"63","author":[{"given":"Bindia","family":"Jharap","sequence":"first","affiliation":[{"name":"Department of Gastroenterology and Hepatology, VU University Medical Center, Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nanne K H","family":"de Boer","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology and Hepatology, VU University Medical Center, Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pieter","family":"Stokkers","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology and Hepatology, Academic Medical Center, Amsterdam, The Netherlands"},{"name":"Sint Lucas Andreas Hospital, Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel W","family":"Hommes","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, The Netherlands"},{"name":"UCLA Health System, Los Angeles, California, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bas","family":"Oldenburg","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology and Hepatology, University Medical Center Utrecht, Utrecht, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gerard","family":"Dijkstra","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C Janneke","family":"van der Woude","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dirk J","family":"de Jong","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology and Hepatology, Radboud University Medical Center, Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chris J J","family":"Mulder","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology and Hepatology, VU University Medical Center, Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruurd M","family":"van Elburg","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, VU University Medical Center, Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adriaan A","family":"van Bodegraven","sequence":"additional","affiliation":[{"name":"Department of Gastroenterology and Hepatology, VU University Medical Center, Amsterdam, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"name":"for the Dutch Initiative on Crohn and Colitis","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2013,2,19]]},"reference":[{"key":"2025121223554505000_63.3.451.1","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM198005013021801"},{"key":"2025121223554505000_63.3.451.2","unstructured":"Sandborn W Sutherland L Pearson D . 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