{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T14:23:02Z","timestamp":1785507782468,"version":"3.56.0"},"reference-count":37,"publisher":"Wiley","issue":"13","license":[{"start":{"date-parts":[[2013,9,11]],"date-time":"2013-09-11T00:00:00Z","timestamp":1378857600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["obgyn.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["BJOG"],"published-print":{"date-parts":[[2013,12]]},"abstract":"<jats:sec><jats:title>Objective<\/jats:title><jats:p>To determine whether outpatient exposure to calcium\u2010channel blockers (<jats:styled-content style=\"fixed-case\">CCB<\/jats:styled-content>s) at the time of delivery is associated with an increased risk for postpartum haemorrhage (<jats:styled-content style=\"fixed-case\">PPH<\/jats:styled-content>).<\/jats:p><\/jats:sec><jats:sec><jats:title>Design<\/jats:title><jats:p>Cohort study.<\/jats:p><\/jats:sec><jats:sec><jats:title>Setting<\/jats:title><jats:p>United States of America.<\/jats:p><\/jats:sec><jats:sec><jats:title>Population or sample<\/jats:title><jats:p>Medicaid beneficiaries.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>We identified a cohort of 9750 patients with outpatient prescriptions for <jats:styled-content style=\"fixed-case\">CCB<\/jats:styled-content>s, methyldopa, or labetalol for pre\u2010existing or gestational hypertension whose days of supply overlapped with delivery; 1226 were exposed to <jats:styled-content style=\"fixed-case\">CCB<\/jats:styled-content>s. The risk of <jats:styled-content style=\"fixed-case\">PPH<\/jats:styled-content> was compared in those exposed to <jats:styled-content style=\"fixed-case\">CCB<\/jats:styled-content>s to those exposed to methyldopa or labetalol. Propensity score matching and stratification were used to address potential confounding.<\/jats:p><\/jats:sec><jats:sec><jats:title>Main outcome measures<\/jats:title><jats:p>The occurrence of <jats:styled-content style=\"fixed-case\">PPH<\/jats:styled-content> during the delivery hospitalisation.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>There were 27 patients exposed to <jats:styled-content style=\"fixed-case\">CCB<\/jats:styled-content>s (2.2%) and 232 patients exposed to methyldopa or labetalol (2.7%) who experienced <jats:styled-content style=\"fixed-case\">PPH<\/jats:styled-content>. After accounting for confounders, there was no meaningful association between <jats:styled-content style=\"fixed-case\">CCB<\/jats:styled-content> exposure and <jats:styled-content style=\"fixed-case\">PPH<\/jats:styled-content> in the propensity score matched (odds ratio 0.77, 95% CI 0.50\u20131.18) or stratified (odds ratio 0.79, 95% CI 0.53\u20131.19) analyses. Similar results were obtained across multiple sensitivity analyses.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>The outpatient use of <jats:styled-content style=\"fixed-case\">CCB<\/jats:styled-content>s in late pregnancy for the treatment of hypertension does not increase the risk of <jats:styled-content style=\"fixed-case\">PPH<\/jats:styled-content>.<\/jats:p><\/jats:sec>","DOI":"10.1111\/1471-0528.12428","type":"journal-article","created":{"date-parts":[[2013,9,11]],"date-time":"2013-09-11T13:06:29Z","timestamp":1378904789000},"page":"1668-1677","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Outpatient calcium\u2010channel blockers and the risk of postpartum haemorrhage: a cohort study"],"prefix":"10.1111","volume":"120","author":[{"given":"BT","family":"Bateman","sequence":"first","affiliation":[{"name":"Division of Pharmacoepidemiology and Pharmacoeconomics Department of Medicine Brigham and Women's Hospital and Harvard Medical School Boston MA USA"},{"name":"Department of Anesthesiology Critical Care, and Pain Medicine Massachusetts General Hospital Harvard Medical School Boston MA USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S","family":"Hernandez\u2010Diaz","sequence":"additional","affiliation":[{"name":"Department of Epidemiology Harvard School of Public Health Boston MA USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"KF","family":"Huybrechts","sequence":"additional","affiliation":[{"name":"Division of Pharmacoepidemiology and Pharmacoeconomics Department of Medicine Brigham and Women's Hospital and Harvard Medical School Boston MA USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K","family":"Palmsten","sequence":"additional","affiliation":[{"name":"Department of Epidemiology Harvard School of Public Health Boston MA 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