{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T09:03:23Z","timestamp":1789635803151,"version":"4.0.0"},"reference-count":21,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T00:00:00Z","timestamp":1789603200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Objective: To evaluate the agreement between non-invasive hemoglobin (SpHb) and venous complete blood count (CBC) in measurements of Hb in pregnant women and to compare the diagnostic performance in detecting anemia. Methods: A prospective cross-sectional study enrolled 660 Thai pregnant women, with 220 participants in each trimester. SpHb was measured at the thumb (tHb) and index finger (fHb) using the Masimo Rad-67, while venous CBC hemoglobin (CBC-Hb) served as the reference. Agreement between SpHb and CBC-Hb was evaluated using Bland\u2013Altman analysis and the intraclass correlation coefficient (ICC). Potential factors influencing SpHb measurement accuracy were identified using generalized linear models, and the diagnostic performance of the resulting predictive models was subsequently evaluated. Results: The mean difference between SpHb and CBC-Hb was significant, with SpHb consistently overestimating hemoglobin concentrations across all trimesters. Consequently, SpHb demonstrated very low sensitivity (2.1% for tHb and 3.2% for fHb) but high specificity for detecting maternal anemia. Agreement with CBC-Hb was poor for absolute measurements (ICC = 0.221\u20130.278) but moderate for consistency (ICC = 0.615\u20130.650), indicating moderate precision but poor accuracy. Although optimized SpHb cut-offs substantially improved diagnostic performance, the two methods remained non-interchangeable. Measurement accuracy was significantly influenced by gestational trimester, maternal BMI, and perfusion index, underscoring the need for pregnancy- and ethnicity-specific calibration algorithms. Conclusions: Although adjustment models improved the diagnostic performance of SpHb for detecting maternal anemia, the substantial positive systematic bias and only moderate agreement suggest that SpHb should not replace CBC-Hb for hemoglobin measurement without further calibration. With these refinements, non-invasive Hb measurement may become a practical and effective screening approach in pregnancy.<\/jats:p>","DOI":"10.3390\/diagnostics16183005","type":"journal-article","created":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T08:03:17Z","timestamp":1789632197000},"page":"3005","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Validation of Non-Invasive Hemoglobin Measurement and Its Utility for Anemia Screening in Pregnancy: A Cross-Sectional Diagnostic Accuracy Study"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4838-175X","authenticated-orcid":false,"given":"Suchaya","family":"Luewan","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand"},{"name":"Fetal Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"}]},{"given":"Mattanaporn","family":"Wongyai","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3389-6478","authenticated-orcid":false,"given":"Theera","family":"Tongsong","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand"},{"name":"Fetal Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,17]]},"reference":[{"key":"ref_1","unstructured":"WHO (2025). WHO Global Anaemia Estimates, WHO. [2025th ed.]."},{"key":"ref_2","first-page":"553","article-title":"The prevalence and determinants of iron deficiency anemia in rural Thai-Muslim pregnant women in Pattani Province","volume":"37","author":"Piammongkol","year":"2006","journal-title":"Southeast Asian J. Trop. Med. Public Health"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1080\/00034983.1967.11686455","article-title":"Iron-deficiency anaemia in Bangkok, Thailand: Anaemia in pregnancy","volume":"61","author":"Sundharagiati","year":"1967","journal-title":"Ann. Trop. Med. Parasitol."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"(2021). Anemia in Pregnancy: ACOG Practice Bulletin, Number 233. Obstet. Gynecol., 138, e55\u2013e64.","DOI":"10.1097\/AOG.0000000000004477"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1025","DOI":"10.1007\/s10877-018-0101-z","article-title":"Accuracy and trending of non-invasive hemoglobin measurement during different volume and perfusion statuses","volume":"32","author":"Adel","year":"2018","journal-title":"J. Clin. Monit. Comput."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"592","DOI":"10.1016\/j.amjsurg.2011.01.020","article-title":"Validation of noninvasive hemoglobin measurements using the Masimo Radical-7 SpHb Station","volume":"201","author":"Causey","year":"2011","journal-title":"Am. J. Surg."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"50","DOI":"10.12688\/gatesopenres.14499.1","article-title":"Comparison of Masimo Total Hemoglobin SpHb(R) continuous non-invasive hemoglobin monitoring device with laboratory complete blood count measurement using venous sample: Protocol for an observational substudy of the Pregnancy Risk and Infant Surveillance and Measurement Alliance Maternal and Newborn Health (PRISMA MNH) study","volume":"7","author":"Farooq","year":"2023","journal-title":"Gates Open Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1177\/0310057X1504300310","article-title":"Systematic review and meta-analysis of method comparison studies of Masimo pulse co-oximeters (Radical-7 or Pronto-7) and HemoCue(R) absorption spectrometers (B-Hemoglobin or 201+) with laboratory haemoglobin estimation","volume":"43","author":"Hiscock","year":"2015","journal-title":"Anaesth. Intensive Care"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"315","DOI":"10.1111\/trf.17237","article-title":"Non-invasive hemoglobin estimation for preoperative anemia screening","volume":"63","author":"Jacob","year":"2023","journal-title":"Transfusion"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"548","DOI":"10.1097\/ALN.0b013e3182270c22","article-title":"Comparison of the accuracy of noninvasive hemoglobin monitoring by spectrophotometry (SpHb) and HemoCue(R) with automated laboratory hemoglobin measurement","volume":"115","author":"Lamhaut","year":"2011","journal-title":"Anesthesiology"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1302","DOI":"10.1213\/ANE.0b013e31826b7e38","article-title":"The accuracy of noninvasive hemoglobin monitoring using the radical-7 pulse CO-Oximeter in children undergoing neurosurgery","volume":"115","author":"Park","year":"2012","journal-title":"Anesth. Analg."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"920","DOI":"10.1213\/ANE.0000000000000369","article-title":"Trending and accuracy of noninvasive hemoglobin monitoring in pediatric perioperative patients","volume":"119","author":"Patino","year":"2014","journal-title":"Anesth. Analg."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1016\/j.jss.2014.12.051","article-title":"A noninvasive hemoglobin monitor in the pediatric intensive care unit","volume":"195","author":"Phillips","year":"2015","journal-title":"J. Surg. Res."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1093\/bja\/aer373","article-title":"Non-invasive haemoglobin measurement in patients undergoing elective Caesarean section","volume":"108","author":"Butwick","year":"2012","journal-title":"Br. J. Anaesth."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Farooq, F., Wei, Y., Pan, Q., Proctor, A., Baumann, S.G., Kasadhe, K., Owour, H., Sagam, C., Mazhar, A., and Yazdani, N. (2025). Comparison of Masimo Rad-67 SpHb non-invasive hemoglobin monitoring device with complete blood count measurement for use in pregnancy: An observational multi-site cohort study. medRxiv.","DOI":"10.64898\/2025.12.14.25342241"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Koech, A., Mwaniki, I., Mutunga, J., Mukhanya, M., Mwadime, E., Ochieng, M., Mwashigadi, G., Mistry, H.D., Craik, R., and von Dadelszen, P. (2024). Diagnostic accuracy of a non-invasive spot-check hemoglobin meter, Masimo Rad-67(R) pulse CO-Oximeter(R), in detection of anemia in antenatal care settings in Kenya. Front. Glob. Women\u2019s Health, 5.","DOI":"10.3389\/fgwh.2024.1427261"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"532","DOI":"10.2174\/1573405617666210823100316","article-title":"NIR-based Sensing System for Non-invasive Detection of Hemoglobin for Point-of-care Applications","volume":"18","author":"Kumar","year":"2022","journal-title":"Curr. Med. Imaging"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1052","DOI":"10.1213\/ANE.0b013e31822c9679","article-title":"The accuracy of noninvasive hemoglobin measurement by multiwavelength pulse oximetry after cardiac surgery","volume":"113","author":"Nguyen","year":"2011","journal-title":"Anesth. Analg."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1016\/j.csbj.2025.07.013","article-title":"The impact of sensor application site on continuous noninvasive haemoglobin trends","volume":"28","author":"Andrijauskas","year":"2025","journal-title":"Comput. Struct. Biotechnol. J."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"178","DOI":"10.1111\/anae.16174","article-title":"Baseline haemoglobin variability by measurement technique in pregnant people on the day of childbirth","volume":"79","author":"Caulfield","year":"2024","journal-title":"Anaesthesia"},{"key":"ref_21","first-page":"11","article-title":"Assessment of noninvasive, percutaneous hemoglobin measurement in pregnant and early postpartum women","volume":"7","author":"Yoshida","year":"2014","journal-title":"Med. Devices"}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/18\/3005\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T08:27:02Z","timestamp":1789633622000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/18\/3005"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,17]]},"references-count":21,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["diagnostics16183005"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics16183005","relation":{},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,17]]}}}