{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T13:08:18Z","timestamp":1790082498288,"version":"4.0.1"},"reference-count":37,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2023,12,9]],"date-time":"2023-12-09T00:00:00Z","timestamp":1702080000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100013348","name":"Innosuisse","doi-asserted-by":"publisher","award":["17324.1 PFLS-LS"],"award-info":[{"award-number":["17324.1 PFLS-LS"]}],"id":[{"id":"10.13039\/501100013348","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100013348","name":"Innosuisse","doi-asserted-by":"publisher","award":["28715.1 IP-LS"],"award-info":[{"award-number":["28715.1 IP-LS"]}],"id":[{"id":"10.13039\/501100013348","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100013348","name":"Innosuisse","doi-asserted-by":"publisher","award":["40347.1 IP-LS"],"award-info":[{"award-number":["40347.1 IP-LS"]}],"id":[{"id":"10.13039\/501100013348","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>(1) Background: Hormonal fluctuations across the menstrual cycle lead to multiple changes in physiological parameters such as body temperature, cardiovascular function, respiratory rate and perfusion. Electronic wearables analyzing those parameters might present a convenient alternative to urinary ovulation tests for predicting the fertile window. (2) Methods: We conducted a prospective observational study including women aged 18\u201345 years without current hormonal therapy who used a wrist-worn medical device and urinary ovulation tests for a minimum of three cycles. We analyzed the accuracy of both the retrospective and prospective algorithms using a generalized linear mixed-effects model. The findings were compared to real-world data from bracelet users who also reported urinary ovulation tests. (3) Results: A total of 61 study participants contributing 205 cycles and 6081 real-life cycles from 3268 bracelet users were included in the analysis. The mean error in identifying ovulation with the wrist-worn medical device retrospective algorithm in the clinical study was 0.31 days (95% CI \u22120.13 to 0.75). The retrospective algorithm identified 75.4% of fertile days, and the prospective algorithm identified 73.8% of fertile days correctly within the pre-specified equivalence limits (\u00b12 days). The quality of the retrospective algorithm in the clinical study could be confirmed by real-world data. (4) Conclusion: Our data indicate that wearable sensors may be used to accurately detect the periovulatory period.<\/jats:p>","DOI":"10.3390\/s23249730","type":"journal-article","created":{"date-parts":[[2023,12,11]],"date-time":"2023-12-11T14:12:51Z","timestamp":1702303971000},"page":"9730","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Can Wrist-Worn Medical Devices Correctly Identify Ovulation?"],"prefix":"10.3390","volume":"23","author":[{"given":"Angela","family":"Niggli","sequence":"first","affiliation":[{"name":"Department of Reproductive Endocrinology, University Hospital of Z\u00fcrich, Frauenklinikstrasse 10, 8091 Z\u00fcrich, Switzerland"},{"name":"Faculty of Medicine, University of Zurich, 8032 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martina","family":"Rothenb\u00fchler","sequence":"additional","affiliation":[{"name":"Ava AG, Gutstrasse 73, 8055 Z\u00fcrich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maike","family":"Sachs","sequence":"additional","affiliation":[{"name":"Department of Reproductive Endocrinology, University Hospital of Z\u00fcrich, Frauenklinikstrasse 10, 8091 Z\u00fcrich, Switzerland"},{"name":"Faculty of Medicine, University of Zurich, 8032 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Brigitte","family":"Leeners","sequence":"additional","affiliation":[{"name":"Department of Reproductive Endocrinology, University Hospital of Z\u00fcrich, Frauenklinikstrasse 10, 8091 Z\u00fcrich, Switzerland"},{"name":"Faculty of Medicine, University of Zurich, 8032 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,12,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"767","DOI":"10.1016\/j.fertnstert.2013.12.006","article-title":"Knowledge, attitudes, and practices regarding conception and fertility: A population-based survey among reproductive-age United States women","volume":"101","author":"Lundsberg","year":"2014","journal-title":"Fertil. Steril."},{"key":"ref_2","first-page":"1333","article-title":"Timing intercourse to achieve pregnancy: Current evidence","volume":"100","author":"Stanford","year":"2002","journal-title":"Obstet. Gynecol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"828052","DOI":"10.3389\/fgwh.2022.828052","article-title":"Fertility Knowledge among Women Struggling to Conceive without Medical Intervention: A Brief Report","volume":"3","author":"Halleran","year":"2022","journal-title":"Front. Glob. Womens Health"},{"key":"ref_4","first-page":"CD011345","article-title":"Timed intercourse for couples trying to conceive","volume":"9","author":"Gibbons","year":"2023","journal-title":"Cochrane Database Syst. Rev."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1319","DOI":"10.1016\/j.fertnstert.2015.01.031","article-title":"Self-identification of the clinical fertile window and the ovulation period","volume":"103","author":"Ecochard","year":"2015","journal-title":"Fertil. Steril."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1016\/S0015-0282(16)47592-8","article-title":"Clinical validation of enzymeimmunoassay of human luteinizing hormone (hLH) in the detection of the preovulatory luteinizing hormone (LH) surge in urine","volume":"41","author":"Singh","year":"1984","journal-title":"Fertil. Steril."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"900","DOI":"10.1016\/S0015-0282(99)00365-9","article-title":"Efficacy of methods for determining ovulation in a natural family planning program","volume":"72","author":"Guida","year":"1999","journal-title":"Fertil. Steril."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1016\/0028-2243(92)90041-V","article-title":"The reliability, acceptability and applications of basal body temperature (BBT) records in the diagnosis and treatment of infertility","volume":"47","author":"Martinez","year":"1992","journal-title":"Eur. J. Obstet. Gynecol. Reprod. Biol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2478","DOI":"10.1093\/humrep\/15.12.2478","article-title":"Prediction of ovulation by urinary hormone measurements with the home use ClearPlan Fertility Monitor: Comparison with transvaginal ultrasound scans and serum hormone measurements","volume":"15","author":"Behre","year":"2000","journal-title":"Hum. Reprod."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.jmwh.2004.07.001","article-title":"New low- and high-tech calendar methods of family planning","volume":"50","author":"Fehring","year":"2005","journal-title":"J. Midwifery Womens Health"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Shilaih, M., Goodale, B.M., Falco, L., K\u00fcbler, F., De Clerck, V., and Leeners, B. (2018). Modern fertility awareness methods: Wrist wearables capture the changes of temperature associated with the menstrual cycle. Biosci. Rep., 38.","DOI":"10.1042\/BSR20171279"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1716","DOI":"10.1039\/C9AN02169H","article-title":"Modulation of saliva pattern and accurate detection of ovulation using an electrolyte pre-deposition-based method: A pilot study","volume":"145","author":"Lee","year":"2020","journal-title":"Analyst"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"92","DOI":"10.4103\/jmss.JMSS_18_20","article-title":"Development of a Permanent Device for Fertility Period Detection by Basal Body Temperature and Analysis of the Cervical Mucus Potential of Hydrogen","volume":"11","author":"Mansouri","year":"2021","journal-title":"J. Med. Signals Sens."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"238","DOI":"10.1002\/btm2.10058","article-title":"Detection of ovulation, a review of currently available methods","volume":"2","author":"Su","year":"2017","journal-title":"Bioeng. Transl. Med."},{"key":"ref_15","first-page":"60","article-title":"Increased Chance of Live Birth following Use of Connected Ovulation Test System: Outcome Results from a Randomized Controlled Trial","volume":"3","author":"Johnson","year":"2022","journal-title":"Womens Health Rep."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Hurst, B.S., Davies, K., Milnes, R.S., Knowles, T.G., and Pirrie, A. (2022). Novel Technique for Confirmation of the Day of Ovulation and Prediction of Ovulation in Subsequent Cycles Using a Skin-Worn Sensor in a Population with Ovulatory Dysfunction: A Side-by-Side Comparison with Existing Basal Body Temperature Algorithm and Vaginal Core Body Temperature Algorithm. Front. Bioeng. Biotechnol., 10.","DOI":"10.3389\/fbioe.2022.807139"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"565","DOI":"10.1111\/j.1469-7793.2001.0565k.x","article-title":"Sleep and 24 hour body temperatures: A comparison in young men, naturally cycling women and women taking hormonal contraceptives","volume":"530","author":"Baker","year":"2001","journal-title":"J. Physiol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"496","DOI":"10.1046\/j.1365-2281.2000.00285.x","article-title":"Cardiovascular functioning during the menstrual cycle","volume":"20","author":"Moran","year":"2000","journal-title":"Clin. Physiol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"996","DOI":"10.1111\/psyp.12250","article-title":"Changes in resting heart rate variability across the menstrual cycle","volume":"51","author":"Tenan","year":"2014","journal-title":"Psychophysiology."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"H765","DOI":"10.1152\/ajpheart.01283.2008","article-title":"Influence of the menstrual cycle on nonlinear properties of heart rate variability in young women","volume":"297","author":"Bai","year":"2009","journal-title":"Am J. Physiol. Heart Circ. Physiol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"462","DOI":"10.1046\/j.1365-2133.1998.02410.x","article-title":"The influence of female sex hormones on skin thickness: Evaluation using 20 MHz sonography","volume":"139","author":"Eisenbeiss","year":"1998","journal-title":"Br. J. Dermatol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/j.contraception.2006.10.011","article-title":"The oral contraceptive containing 30 \u03bcg of ethinylestradiol plus 3 mg of drospirenone is able to antagonize the increase of extracellular water occurring in healthy young women during the luteal phase of the menstrual cycle: An observational study","volume":"75","author":"Fruzzetti","year":"2007","journal-title":"Contraception"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2618","DOI":"10.1016\/j.psyneuen.2013.06.005","article-title":"Autonomic regulation across phases of the menstrual cycle and sleep stages in women with premenstrual syndrome and healthy controls","volume":"38","author":"Nicholas","year":"2013","journal-title":"Psychoneuroendocrinology"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"e14550","DOI":"10.14814\/phy2.14550","article-title":"Oral contraceptives and menstrual cycle influence autonomic reflex function","volume":"8","author":"Assadpour","year":"2020","journal-title":"Physiol. Rep."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1902","DOI":"10.1152\/jappl.1985.59.6.1902","article-title":"Influence of menstrual cycle on shivering, skin blood flow, and sweating responses measured at night","volume":"59","author":"Hessemer","year":"1985","journal-title":"J. Appl. Physiol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1643","DOI":"10.1152\/jappl.2000.88.5.1643","article-title":"Estrogen modifies the temperature effects of progesterone","volume":"88","author":"Stachenfeld","year":"2000","journal-title":"J. Appl. Physiol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"e13404","DOI":"10.2196\/13404","article-title":"Wearable sensors reveal menses-driven changes in physiology and enable prediction of the fertile window: An observational study","volume":"21","author":"Goodale","year":"2019","journal-title":"J. Med. Internet Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"564","DOI":"10.2741\/3634","article-title":"The circadian rhythm of body temperature","volume":"15","author":"Refinetti","year":"2010","journal-title":"Front. Biosci."},{"key":"ref_29","first-page":"2825","article-title":"Scikit-learn: Machine learning in Python","volume":"12","author":"Pedregosa","year":"2011","journal-title":"J. Mach. Learn. Res."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Chow, S.-C., and Liu, J.-P. (2013). Design and Analysis of Clinical Trials: Concepts and Methodologies, Wiley. [3rd ed.].","DOI":"10.1002\/9781118458167"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Chow, S.-C., Shao, J., Wang, H., and Lokhnygina, Y. (2017). Sample Size Calculations in Clinical Research, Chapman and Hall\/CRC. [3rd ed.].","DOI":"10.1201\/9781315183084"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1177\/1948550617697177","article-title":"Equivalence Tests","volume":"8","author":"Lakens","year":"2017","journal-title":"Soc. Psychol. Pers. Sci."},{"key":"ref_33","first-page":"378","article-title":"Package \u2018glmmTMB\u2019. Generalized Linear Mixed Models using Template Model Builder","volume":"9","author":"Magnusson","year":"2017","journal-title":"R J."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"546","DOI":"10.1136\/bmj.327.7414.546","article-title":"Anovulation","volume":"327","author":"Taylor","year":"2003","journal-title":"BMJ"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1017\/S0007114518000818","article-title":"Dietary minerals, reproductive hormone levels and sporadic anovulation: Associations in healthy women with regular menstrual cycles","volume":"120","author":"Kim","year":"2018","journal-title":"Br. J. Nutr."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"147","DOI":"10.3122\/jabfm.2009.02.080038","article-title":"Fertility awareness-based methods: Another option for family planning","volume":"22","author":"Pallone","year":"2009","journal-title":"J. Am. Board Fam. Med."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"e20710","DOI":"10.2196\/20710","article-title":"The Accuracy of Wrist Skin Temperature in Detecting Ovulation Compared to Basal Body Temperature: Prospective Comparative Diagnostic Accuracy Study","volume":"23","author":"Zhu","year":"2021","journal-title":"J. Med. Internet Res."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/24\/9730\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:36:04Z","timestamp":1760132164000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/24\/9730"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,12,9]]},"references-count":37,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2023,12]]}},"alternative-id":["s23249730"],"URL":"https:\/\/doi.org\/10.3390\/s23249730","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,12,9]]}}}