{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T22:47:09Z","timestamp":1785883629887,"version":"3.56.0"},"reference-count":21,"publisher":"Springer Science and Business Media LLC","issue":"8","license":[{"start":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T00:00:00Z","timestamp":1781049600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T00:00:00Z","timestamp":1781049600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Hypertens Res"],"published-print":{"date-parts":[[2026,8]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>\n                    In this study, we characterized the physiological blood pressure (BP) trajectories from an estimated pre-pregnancy period through pregnancy, labor, and postpartum among low-risk, normotensive women. This retrospective multicenter observational study was conducted at 12 primary obstetric care facilities in Japan and included 14,240 low-risk, normotensive women with term singleton deliveries between 2011 and 2018. Longitudinal outpatient BP trajectories during pregnancy and the postpartum period were modeled using linear mixed-effects models with restricted cubic splines. The pre-pregnancy BP was approximated using 1:1 matching with non-pregnant women undergoing routine health checkups. Changes in intrapartum BP were evaluated in women who underwent vaginal delivery (\n                    <jats:italic>n<\/jats:italic>\n                    \u2009=\u200911,836). The outpatient BP followed a classic gestational pattern, with a nadir at approximately 25 weeks of gestation, followed by a gradual increase toward term. The estimated pre-pregnancy BP was lower than the outpatient BP measured during early pregnancy. During the first stage of labor, systolic and diastolic BPs increased by up to 15.7\u2009mmHg and 13.4\u2009mmHg, respectively, compared with the final outpatient measurements, returning to near-outpatient levels within 2\u2009h after delivery. During the postpartum period, the BP increased, peaked at days 5\u20137, and then gradually declined by approximately 5 weeks, converging toward non-pregnant levels. Low-risk normotensive women demonstrated elevated BP in early pregnancy relative to the estimated non-pregnant baseline during labor and in the first postpartum week. These data provide physiological reference patterns that may aid the interpretation of intrapartum and postpartum hypertension.\n                  <\/jats:p>","DOI":"10.1038\/s41440-026-02708-3","type":"journal-article","created":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T03:20:04Z","timestamp":1781061604000},"page":"2417-2426","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Blood pressure trajectories during pregnancy, labor, and postpartum period: a multicenter study in Japan"],"prefix":"10.1038","volume":"49","author":[{"given":"Takafumi","family":"Ushida","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takuma","family":"Shimaya","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tatsuo","family":"Inamura","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Satoru","family":"Katsuki","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sho","family":"Tano","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Seiko","family":"Matsuo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kazuya","family":"Fuma","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shigeru","family":"Yoshida","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mamoru","family":"Yamashita","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hiroaki","family":"Kajiyama","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,6,10]]},"reference":[{"key":"2708_CR1","doi-asserted-by":"publisher","first-page":"1003","DOI":"10.1161\/CIRCULATIONAHA.114.009029","volume":"130","author":"M Sanghavi","year":"2014","unstructured":"Sanghavi M, Rutherford JD. Cardiovascular physiology of pregnancy. Circulation. 2014;130:1003\u20138.","journal-title":"Circulation"},{"key":"2708_CR2","doi-asserted-by":"publisher","first-page":"317","DOI":"10.1016\/j.ccl.2012.05.004","volume":"30","author":"JG Ouzounian","year":"2012","unstructured":"Ouzounian JG, Elkayam U. Physiologic changes during normal pregnancy and delivery. Cardiol Clin. 2012;30:317\u201329.","journal-title":"Cardiol Clin"},{"key":"2708_CR3","doi-asserted-by":"publisher","first-page":"e6","DOI":"10.1016\/j.hlc.2020.10.001","volume":"30","author":"A Morton","year":"2021","unstructured":"Morton A. Physiological changes and cardiovascular investigations in pregnancy. Heart Lung Circ. 2021;30:e6\u2013e15.","journal-title":"Heart Lung Circ"},{"key":"2708_CR4","first-page":"430","volume":"11","author":"WN van Mook","year":"2005","unstructured":"van Mook WN, Peeters L. Severe cardiac disease in pregnancy, part I: hemodynamic changes and complaints during pregnancy, and general management of cardiac disease in pregnancy. Curr Opin Crit Care. 2005;11:430\u20134.","journal-title":"Curr Opin Crit Care"},{"key":"2708_CR5","doi-asserted-by":"publisher","DOI":"10.1186\/s12884-021-03599-7","volume":"21","author":"H Teng","year":"2021","unstructured":"Teng H, Wang Y, Han B, Liu J, Cao Y, Wang J, et al. Gestational systolic blood pressure trajectories and risk of adverse maternal and perinatal outcomes in Chinese women. BMC Pregnancy Childbirth. 2021;21:155.","journal-title":"BMC Pregnancy Childbirth"},{"key":"2708_CR6","doi-asserted-by":"publisher","first-page":"770","DOI":"10.1111\/jch.14494","volume":"24","author":"F Chan","year":"2022","unstructured":"Chan F, Shen S, Huang P, He J, Wei X, Lu J, et al. Blood pressure trajectories during pregnancy and preterm delivery: a prospective cohort study in China. J Clin Hypertens. 2022;24:770\u20138.","journal-title":"J Clin Hypertens"},{"key":"2708_CR7","doi-asserted-by":"publisher","first-page":"103","DOI":"10.1016\/j.ejogrb.2014.11.020","volume":"184","author":"J Cohen","year":"2015","unstructured":"Cohen J, Vaiman D, Sibai BM, Haddad B. Blood pressure changes during the first stage of labor and for the prediction of early postpartum preeclampsia: a prospective study. Eur J Obstet, Gynecol, Reprod Biol. 2015;184:103\u20137.","journal-title":"Eur J Obstet, Gynecol, Reprod Biol"},{"key":"2708_CR8","doi-asserted-by":"publisher","first-page":"74","DOI":"10.1016\/j.ijoa.2017.03.003","volume":"31","author":"JC Kuhn","year":"2017","unstructured":"Kuhn JC, Falk RS, Langes\u00e6ter E. Haemodynamic changes during labour: continuous minimally invasive monitoring in 20 healthy parturients. Int J Obstet Anesth. 2017;31:74\u201383.","journal-title":"Int J Obstet Anesth"},{"key":"2708_CR9","doi-asserted-by":"publisher","first-page":"241.e1","DOI":"10.1016\/j.ajog.2016.02.046","volume":"215","author":"ME Countouris","year":"2016","unstructured":"Countouris ME, Schwarz EB, Rossiter BC, Althouse AD, Berlacher KL, Jeyabalan A, et al. Effects of lactation on postpartum blood pressure among women with gestational hypertension and preeclampsia. Am J Obstet Gynecol. 2016;215:241.e1\u20138.","journal-title":"Am J Obstet Gynecol"},{"key":"2708_CR10","doi-asserted-by":"publisher","first-page":"577","DOI":"10.1016\/j.ajog.2003.08.030","volume":"190","author":"A Makris","year":"2004","unstructured":"Makris A, Thornton C, Hennessy A. Postpartum hypertension and nonsteroidal analgesia. Am J Obstet Gynecol. 2004;190:577\u20138.","journal-title":"Am J Obstet Gynecol"},{"key":"2708_CR11","doi-asserted-by":"publisher","first-page":"48","DOI":"10.1016\/j.preghy.2021.08.118","volume":"26","author":"T Ushida","year":"2021","unstructured":"Ushida T, Kotani T, Imai K, Nakano-Kobayashi T, Iitani Y, Nakamura N, et al. Prevalence and risk factors of labor-onset hypertension: a multicenter study in Japan. Pregnancy Hypertens. 2021;26:48\u201353.","journal-title":"Pregnancy Hypertens"},{"key":"2708_CR12","doi-asserted-by":"publisher","unstructured":"Ushida T, Nakamura N, Katsuki S, Mizutani H, Iitani Y, Imai K, et al. New-onset postpartum hypertension in women without a history of hypertensive disorders of pregnancy: a multicenter study in Japan. Hypertens Res. 2023. https:\/\/doi.org\/10.1038\/s41440-023-01372-1).","DOI":"10.1038\/s41440-023-01372-1)"},{"key":"2708_CR13","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-017-06606-0","volume":"7","author":"M Shen","year":"2017","unstructured":"Shen M, Tan H, Zhou S, Smith GN, Walker MC, Wen SW. Trajectory of blood pressure change during pregnancy and the role of pre-gravid blood pressure: a functional data analysis approach. Sci Rep. 2017;7:6227.","journal-title":"Sci Rep"},{"key":"2708_CR14","doi-asserted-by":"publisher","first-page":"1655","DOI":"10.1089\/jwh.2021.0360","volume":"31","author":"D Enkhmaa","year":"2022","unstructured":"Enkhmaa D, Ganmaa D, Tanz LJ, Rich-Edwards JW, Stuart JJ, Enkhtur S, et al. Changes in vascular function from preconception to postpartum among Mongolian women. J women\u2019s health (2002. 2022;31:1655\u201363.","journal-title":"J women\u2019s health (2002"},{"key":"2708_CR15","doi-asserted-by":"publisher","first-page":"702","DOI":"10.1111\/ped.12331","volume":"56","author":"K Itabashi","year":"2014","unstructured":"Itabashi K, Miura F, Uehara R, Nakamura Y. New Japanese neonatal anthropometric charts for gestational age at birth. Pediatrics Int: Off J Jpn Pediatr Soc. 2014;56:702\u20138.","journal-title":"Pediatrics Int: Off J Jpn Pediatr Soc"},{"key":"2708_CR16","doi-asserted-by":"publisher","first-page":"675","DOI":"10.1038\/s41409-019-0679-x","volume":"55","author":"J Gauthier","year":"2020","unstructured":"Gauthier J, Wu QV, Gooley TA. Cubic splines to model relationships between continuous variables and outcomes: a guide for clinicians. Bone Marrow Transpl. 2020;55:675\u201380.","journal-title":"Bone Marrow Transpl"},{"key":"2708_CR17","doi-asserted-by":"publisher","first-page":"89","DOI":"10.5830\/CVJA-2016-021","volume":"27","author":"P Soma-Pillay","year":"2016","unstructured":"Soma-Pillay P, Nelson-Piercy C, Tolppanen H, Mebazaa A. Physiological changes in pregnancy. Cardiovasc J Afr. 2016;27:89\u201394.","journal-title":"Cardiovasc J Afr"},{"key":"2708_CR18","doi-asserted-by":"publisher","first-page":"922","DOI":"10.1161\/HYPERTENSIONAHA.120.14875","volume":"76","author":"CJ Nobles","year":"2020","unstructured":"Nobles CJ, Mendola P, Mumford SL, Silver RM, Kim K, Andriessen VC, et al. Preconception blood pressure and its change in early pregnancy: early risk factors for preeclampsia and gestational hypertension. Hypertension. 2020;76:922\u20139.","journal-title":"Hypertension"},{"key":"2708_CR19","doi-asserted-by":"publisher","first-page":"1563","DOI":"10.1038\/s41440-022-00992-3","volume":"45","author":"Y Suzuki","year":"2022","unstructured":"Suzuki Y, Matsubara K, Watanabe K, Tanaka K, Yamamoto T, Nohira T, et al. A multicenter prospective study of home blood pressure measurement (HBPM) during pregnancy in Japanese women. Hypertens Res. 2022;45:1563\u201374.","journal-title":"Hypertens Res"},{"key":"2708_CR20","doi-asserted-by":"crossref","unstructured":"Metoki H, Ohkubo T, Watanabe Y, Nishimura M, Sato Y, Kawaguchi M, et al. Seasonal trends of blood pressure during pregnancy in Japan: the babies and their parents\u2019 longitudinal observation in the Suzuki Memorial Hospital in the Intrauterine Period study. J Hypertens. 2008;26:2406\u201313.","DOI":"10.1097\/HJH.0b013e32831364a7"},{"key":"2708_CR21","doi-asserted-by":"publisher","DOI":"10.1111\/jch.14949","volume":"27","author":"S Izumi","year":"2025","unstructured":"Izumi S, Nishimura M, Iwama N, Tomita H, Hamada H, Obara T, et al. Pregnancy and postpartum trends in self-measured blood pressure and derived indices: the BOSHI study. J Clin Hypertens. 2025;27:e14949.","journal-title":"J Clin Hypertens"}],"container-title":["Hypertension Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.nature.com\/articles\/s41440-026-02708-3.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41440-026-02708-3","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41440-026-02708-3.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T22:06:31Z","timestamp":1785881191000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.nature.com\/articles\/s41440-026-02708-3"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,10]]},"references-count":21,"journal-issue":{"issue":"8","published-print":{"date-parts":[[2026,8]]}},"alternative-id":["2708"],"URL":"https:\/\/doi.org\/10.1038\/s41440-026-02708-3","relation":{},"ISSN":["0916-9636","1348-4214"],"issn-type":[{"value":"0916-9636","type":"print"},{"value":"1348-4214","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,10]]},"assertion":[{"value":"22 March 2026","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"1 June 2026","order":2,"name":"revised","label":"Revised","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"2 June 2026","order":3,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"10 June 2026","order":4,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"The authors declare no competing interests.","order":1,"name":"Ethics","label":"Conflict of interest","group":{"name":"EthicsHeading","label":"Compliance with ethical standards"}}]}}