Reference intervals for clinical biochemistry and haematology tests during normal pregnancy.

BACKGROUND: Pregnancy induces physiological changes which affect biochemical and haematological parameters. As the significance of laboratory test results change throughout pregnancy, the reference interval (RI) or key result interpretive guide should be specific to pregnancy. This study sought to establish trimester-specific-RIs for routine biochemical and haematological tests in healthy white European women with singleton pregnancies with comparison to RIs for non-pregnant European adults. METHODS: A retrospective analysis of a prospective longitudinal single-centre study of healthy pregnant women conducted between November 2018 and December 2020 in a tertiary academic hospital with approximately 3000 births annually. Inclusion criteria: signed informed consent, age ≥18 years, white European, body mass index (BMI) <25 kg/m2, blood pressure <140/90mmHg, non-smoker, no previous pathology or gestational diabetes. Trimester defined as T1: up to 13 weeks + 6 days, T2: 14-27 weeks + 6 days and T3: ≥28-41 weeks + 6 days. Baseline demographics, anthropometric and laboratory measurements were recorded. In total, 31 biochemical and 10 haematological ISO15189:2012 accredited tests were measured using Roche Cobas® and Sysmex XN-9100™ analysers, respectively. RIs were established according to the International Federation of Clinical Chemistry (IFCC) recommended method. RESULTS: Apparently healthy pregnant women (n = 124) with bio-banked serum samples in each trimester were recruited. At the booking visit, 49.2% (n = 61) of participants were nulliparous, with median age of 34.4 (IQR: 31.3-37.3) years, gestational age of 89 (IQR: 84-93) days, BMI of 22.5 (IQR: 21.0-23.7) kg/m2 and systolic and diastolic blood pressure of 116 (110-125) mmHg and 67 (61-75) mmHg, respectively. CONCLUSIONS: Normative trimester-specific biological intervals for routinely requested biochemical and haematological medical laboratory tests were established. These RIs will be invaluable to result interpretation and the management of pregnant women.

Remote capillary blood collection for HbA1c measurement during the COVID-19 pandemic: A laboratory and patient perspective.

AIMS: The purpose of this study was to assess the clinical performance and user acceptance of capillary blood samples prepared remotely using the MiniCollect® capillary blood collection device as an alternative to blood collection by venepuncture for glycated haemoglobin (HbA1c ) analysis. METHODS: Following written informed consent, a cross-sectional study was conducted in individuals aged ≥18 years with any type of diabetes who routinely self-monitor their blood glucose. Eligible participants recruited whilst attending their routine clinical appointments were required to provide a venous blood sample, prepare a capillary blood sample at home (remotely) and complete a bespoke questionnaire. HbA1c in whole blood collected in ethylenediaminetetraacetic acid was determined by capillary electrophoresis on the Sebia Capillary's 3 Tera analyser following standard operating procedure. RESULTS: HbA1c results from both venous and capillary collection demonstrated good agreement. Passing-Bablok regression: y = 0 + 1x (p = 0.18), Spearman correlation r = 0.986, p < 0.0001. The Bland-Altman difference plot provided a mean difference of 0.3 mmol/mol (2.2%). Over half of the participants found the MiniCollect device easy to use. The majority of participants were in favour of the remote capillary blood collection service and would use it if routinely available. CONCLUSION: The home collection of capillary blood for HbA1c determination is a valuable and convenient alternative to standard venous blood collection as it provides an opportunity to support routine HbA1c monitoring, whilst mitigating the transmission of SARS-CoV-2. This service would additionally allow individuals to attend clinic visits with a HbA1c value, ensuring optimal continuance of patient care for individuals with diabetes.