{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,10]],"date-time":"2026-10-10T03:52:55Z","timestamp":1791604375013,"version":"4.3.4"},"reference-count":15,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[2026,2,16]],"date-time":"2026-02-16T00:00:00Z","timestamp":1771200000000},"content-version":"vor","delay-in-days":46,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"},{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/100009619","name":"Japan Agency for Medical Research and Development","doi-asserted-by":"publisher","award":["JP19mk0101086h0003"],"award-info":[{"award-number":["JP19mk0101086h0003"]}],"id":[{"id":"10.13039\/100009619","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Congenital Anomalies"],"published-print":{"date-parts":[[2026,1]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>\n                    Clarithromycin is a macrolide antibiotic that is widely used, including during pregnancy. However, few studies have examined the safety of clarithromycin alone in early pregnancy. In this two\u2010center retrospective cohort study, we evaluated pregnancy outcomes following first\u2010trimester clarithromycin exposure. Information on medication use and obstetric history was obtained retrospectively. Pregnancy outcomes were collected using patient\u2010completed postal questionnaires. We investigated pregnancy outcomes and the incidence of major anomalies in women who took clarithromycin during the first trimester, and compared them with those in women who took \u03b2\u2010lactams or control drugs known to be safe during pregnancy. The primary outcome was the incidence of major anomalies, and the secondary outcome was overall pregnancy outcomes. The numbers of major anomalies in the clarithromycin group (\n                    <jats:italic>n<\/jats:italic>\n                    \u2009=\u2009347), \u03b2\u2010lactam group (\n                    <jats:italic>n<\/jats:italic>\n                    \u2009=\u20091367), and control group (\n                    <jats:italic>n<\/jats:italic>\n                    \u2009=\u20091313) were 8 (2.31%), 26 (1.90%), and 18 (1.37%), respectively. When restricted to patients with live births only, the numbers of major anomalies in these groups (\n                    <jats:italic>n<\/jats:italic>\n                    \u2009=\u2009333,\n                    <jats:italic>n<\/jats:italic>\n                    \u2009=\u20091323, and\n                    <jats:italic>n<\/jats:italic>\n                    \u2009=\u20091261, respectively) were 8 (2.40%), 25 (1.89%), and 18 (1.43%), respectively, with no significant differences between groups. The odds ratio for major anomalies in the clarithromycin group relative to the control group was 1.70 (95% confidence interval [CI], 0.73\u20133.94), while that relative to the \u03b2\u2010lactam group was 1.28 (95% CI, 0.57\u20132.86). Inverse probability weighting to compensate for small sample sizes also yielded no significant differences. Overall, clarithromycin use during the first trimester was not associated with an increased risk of major anomalies relative to \u03b2\u2010lactams or control drugs.\n                  <\/jats:p>","DOI":"10.1002\/cga.70041","type":"journal-article","created":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T06:25:34Z","timestamp":1771309534000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Clarithromycin Use in the First Trimester Is Not Associated With Fetal Abnormalities"],"prefix":"10.1002","volume":"66","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5109-1120","authenticated-orcid":false,"given":"Tomo","family":"Suzuki","sequence":"first","affiliation":[{"name":"Japan Drug Information Institute in Pregnancy, Integrated Center for Women's Health National Center for Child Health and Development  Tokyo Japan"},{"name":"Division of Obstetrics Center for Maternal\u2010Fetal, Neonatal and Reproductive Medicine, National Center for Child Health and Development  Tokyo Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5569-9275","authenticated-orcid":false,"given":"Mikako","family":"Goto","sequence":"additional","affiliation":[{"name":"Japan Drug Information Institute in Pregnancy, Integrated Center for Women's Health National Center for Child Health and Development  Tokyo Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tatsuhiko","family":"Anzai","sequence":"additional","affiliation":[{"name":"Department of Biostatistics M&amp;D Data Science Center, Institute of Integrated Research, Institute of Science Tokyo  Tokyo Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ritsuko","family":"Yamane","sequence":"additional","affiliation":[{"name":"Department of Pharmacy Toranomon Hospital  Tokyo Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Omi","family":"Watanabe","sequence":"additional","affiliation":[{"name":"Japan Drug Information Institute in Pregnancy, Integrated Center for Women's Health National Center for Child Health and Development  Tokyo Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kunihiko","family":"Takahashi","sequence":"additional","affiliation":[{"name":"Department of Biostatistics M&amp;D Data Science Center, Institute of Integrated Research, Institute of Science Tokyo  Tokyo Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Atsuko","family":"Murashima","sequence":"additional","affiliation":[{"name":"Japan Drug Information Institute in Pregnancy, Integrated Center for Women's Health National Center for Child Health and Development  Tokyo Japan"},{"name":"Department of Rheumatology and Applied Immunology Saitama Medical University  Moroyama Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,2,16]]},"reference":[{"key":"e_1_2_10_2_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0223835"},{"key":"e_1_2_10_3_1","volume-title":"Guidelines for Obstetrical Practice in Japan 2023: Obstetrics Edition","author":"Japan Society of Obstetrics and Gynecology, Japan Association of Obstetricians and Gynecologists","year":"2023"},{"key":"e_1_2_10_4_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0212212"},{"key":"e_1_2_10_5_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0053327"},{"key":"e_1_2_10_6_1","doi-asserted-by":"publisher","DOI":"10.2188\/jea.JE20180014"},{"key":"e_1_2_10_7_1","doi-asserted-by":"publisher","DOI":"10.1002\/pds.3900"},{"key":"e_1_2_10_8_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejogrb.2008.07.008"},{"key":"e_1_2_10_9_1","doi-asserted-by":"publisher","DOI":"10.3390\/v14122708"},{"key":"e_1_2_10_10_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1741\u20104520.2006.00108.x"},{"key":"e_1_2_10_11_1","doi-asserted-by":"publisher","DOI":"10.1111\/jog.14709"},{"key":"e_1_2_10_12_1","doi-asserted-by":"publisher","DOI":"10.1111\/cga.12456"},{"key":"e_1_2_10_13_1","doi-asserted-by":"publisher","DOI":"10.1111\/cga.12471"},{"key":"e_1_2_10_14_1","doi-asserted-by":"publisher","DOI":"10.1067\/mib.2001.113905"},{"key":"e_1_2_10_15_1","doi-asserted-by":"publisher","DOI":"10.3899\/jrheum.200254"},{"key":"e_1_2_10_16_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0122034"}],"container-title":["Congenital 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