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NCT Number: NCT05929326

Reference Intervals of Complete Blood Count and Coagulation Tests in Pregnant Women at Hung Vuong Hospital

Rationale: Pregnancy has major effects on physiology in women. There have been many studies that established reference intervals but none was done in Vietnam. The recommendation by CLSI C28-A3 is that if possible, each laboratory establishes its own reference intervals.

Objective: To establish the reference intervals of complete blood count parameters and Prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen.

Study design: This is a cross-sectional study.

Study population: Pregnant women with no history of disease and normal clinical findings.

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Key information

Conditions

Pregnancy Related

Age range

18 year and older

Sex eligibility

Female

Study type

Observational

Primary location

Hung Vuong Hospital

Ho Chi Minh City, 700000, Vietnam

About this study

Reference intervals (RI) is defined as the central 95% interval of the distribution of values taken from a biological reference population. RI is established for each trimester. The sample needed for each trimester is at least 258 which adds up to 774 when combining three trimesters.

Pregnant women are selected if eligible from obstetrics clinics after history taking and clinical findings. After consent, their blood are then drawn by phlebotomist into an ethylenediamine tetraacetic acid (EDTA) and a trisodium citrate 3.2% blood tube. EDTA samples are run on DxH 900 hematology analyzer, manufactured by Beckman Coulter and citrate samples are run on ACL TOP 550 coagulation analyzer, manufactured by Werfen. The analyzers are verified by laboratory procedure, recommended by Clinical and Laboratory Standards Institute (CLSI) method and quality control is checked before in accordance to the laboratory procedure.

Statistical analysis: Patients were divided into three groups, which are first, second, and third trimester. CLSI EP28-A3c recommended Dixon's D/R ratio outlier test to exclude outliers, where D is the absolute difference between the largest (or smallest) and the second largest (or smallest) observation, and R is the range of all observations. If D is equal to or greater than one-third of R, that observation is considered an outlier and is deleted. After outliers were deleted, the remaining data was tested again for additional outliers until there were no more outliers. A non-parametric method, recommended to establish reference intervals by CLSI EP28-A3c, was used to determine the lower reference limit 2.5th percentile and upper reference limit 97.5th percentile for each group.

Each reference limit was reported along with its 90th confidence interval. Groups were then compared using normal approximation with continuous correction Mann-Whitney U. A two-tailed P-value < 0.05 was considered significant. Statistical analysis was performed using NCSS statistical software (Utah, USA) version 2023

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Singleton Pregnancy

Exclusion criteria

  • Hypertension, Diabetes, Preeclampsia, Gestational Diabetes, Hemoglobinopathy, Current Infection, Positive Screening for Treponema pallidum, Hepatitis B Virus, HIV, usage of anticoagulant drug.

Treatment and study plan

complete blood count, PT, aPTT, fibrinogen tests

Diagnostic Test

Pregnant women who are eligible for the study will have their blood collected to run complete blood count, PT, aPTT, fibrinogen tests

Primary outcomes

  1. Trimester Specific Prothrombin Time Reference Interval

    Time frame: Each participant's blood samples are run immediately after phlebotomy within 30 minutes

    Prothrombin time in seconds, measured on ACL TOP 550 coagulation analyzer

  2. Trimester Specific Activated Partial Thromboplastin Time Reference Interval

    Time frame: Each participant's blood samples are run immediately after phlebotomy within 30 minutes

    Activated partial thromboplastin time in seconds, measured on ACL TOP 550 coagulation analyzer

  3. Trimester Specific Fibrinogen Reference Interval

    Time frame: Each participant's blood samples are run immediately after phlebotomy within 30 minutes

    Fibrinogen in milligram/deciLiter (mg/dL), measured on ACL TOP 550 coagulation analyzer

  4. Trimester Specific Hemoglobin Reference Interval

    Time frame: Each participant's blood samples are run immediately after phlebotomy within 30 minutes

    Hemoglobin in gram/deciLiter (g/dL), measured on DxH900 hematology analyzer

  5. Trimester Specific Red Blood Cell Count Reference Interval

    Time frame: Each participant's blood samples are run immediately after phlebotomy within 30 minutes

    Red blood cell count in million cells/μl (M/μl), measured on DxH900 hematology analyzer

  6. Trimester Specific White Blood Cell Count Reference Interval

    Time frame: Each participant's blood samples are run immediately after phlebotomy within 30 minutes

    White blood cell count in thousand cells/μl (K/μl), measured on DxH900 hematology analyzer

  7. Trimester Specific Hematocrit Reference Interval

    Time frame: Each participant's blood samples are run immediately after phlebotomy within 30 minutes

    percentage of hematocrit (%), measured on DxH900 Hematology Analyzer

  8. Trimester Specific Platelet Reference Interval

    Time frame: Each participant's blood samples are run immediately after phlebotomy within 30 minutes

    Platelet in thousand cells/microLiter (K/μl), Measured on DxH900 Hematology Analyzer

Sponsors and collaborators

Lead sponsor

Hung Vuong Hospital

Other

Collaborators

  • MITALAB COMPANY LIMITED

Registry information

Official study title

Establishment of Reference Intervals of Complete Blood Count and Coagulation Tests in Pregnant Women at Hung Vuong Hospital

Important dates

Study start
2023
Primary completion
2023
Study completion
2023
First posted
Jul 3, 2023
Registry last updated
Jun 4, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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