Hypertension, Pregnancy-InducedARMFINNCT04012151
Arm and Finger Measurement for Blood Pressure Surveillance
An observational study of Hypertension, Pregnancy-Induced, run by KK Women's and Children's Hospital at 1 site in Singapore.
Trial summary
Accurate blood pressure (BP) measurement is critical in peripartum care. The cuff and bladder sizes affects the accuracy of BP measurement. Current international BP measurement recommendations are based on mid-arm circumference (MAC). Read more about this study
- Who is it for?
- Ages 21 to 50 years, women only
- Conditions the study is for
- Hypertension, Pregnancy-Induced
- What is being tested?
- Physical measurement and Cuff size fitting
- How many people
- 300 participants
- Where
- 1 siteSingapore
- Study dates
- 10 Jul 2019to 31 Dec 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 to 50 years
- Women only
- No healthy volunteers
- Adult
Study population: Pregnant women in Singapore
Who may be able to join
- American Society of Anaesthesiologists physical status 1 or 2 (ASA 1 or 2) parturients at 32 or more weeks of gestation
- Multiparous or nulliparous;
- Age 21-50 years old;
- Undergoing Caesarean section in our institution.
Who cannot join
- Emergent Caesarean section such that consent and measurements cannot be taken.
Trial locations and contacts
1 site in 1 country.
About this study
Accurate blood pressure (BP) measurement is critical in peripartum care. The cuff and bladder sizes affects the accuracy of BP measurement. Current international BP measurement recommendations are based on mid-arm circumference (MAC). However, evidence have shown the discrepancies between these sizes, leading to inaccuracy of BP measurement. This study will measure arm and finger size of 300 parturients in third trimester to determine whether the MAC, finger measurement or body mass index (BMI) is the best clinical predictor for non-standard cuff sizes for BP measurement.
Read the detailed description
Accurate blood pressure (BP) measurement plays an important role in peripartum care as it is essential in detecting hypertensive disorders in pregnancy and medical decision making during the pregnancy. The cuff and bladder size have been highlighted as an important factor affecting the accuracy of BP measurement. Current international BP measurement recommendations are based on mid-arm circumference (MAC) assuming the arm is cylindrical in shape. However, evidence have shown a mismatch between these sizes, leading to BP overestimation or underestimation in obese patients. This is because the shape of the arm is a truncated cone instead of a cylinder, and the cuff will expand irregularly during inflation thus yielding inaccurate BP measurements. This is especially evident in Asian pregnant patients whereby no available guideline can recommend a suitable cuff for parturients with different MAC. Nexfin is a finger cuff device that can be a suitable alternative BP measurement device for such patients. In this study 300 parturients will be recruited in third trimester and undergoing nonemergent caesarean section in KKH. Patients' arm and finger sizes will be measured, and their user experience on current practices on BP measurement. The arm measurements will help to identify the proportion of women that may require non-standard cuff sizes for BP measurement. A conicity index will be determined whether the MAC, finger measurement or BMI is the best clinical predictor. The finger measurements will also help to determine the proportion of women that may require non-standard cuff sizes on the Nexfin device for BP measurement. The knowledge gathered in this pilot study will be used to design future studies in which the accuracy of Nexfin will be compared with standard BP measurement, which in turn will improve BP detection, subsequent patient monitoring and satisfaction.
- Conditions
- Hypertension, Pregnancy-Induced
- Being tested
- Physical measurement, Cuff size fitting
- Keywords
- Blood pressure measurement, Conicity index, Mid arm circumference, Cuff size
- Medical subject headings
- Hypertension, Pregnancy-Induced
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Physical measurementOther
Also called Measurement of fingers and arms
Parturients of gestational week >= 32 weeks will have their arms and fingers measured to generate the conicity index.
Cuff size fittingOther
Also called Cuff fitting for arm and finger
Fit on arm cuff and finger cuff as selected by investigators based on the measurement.
| Study group | Role | What they receive |
|---|---|---|
| Pregnant cohort | Parturients of gestational age >= 32 weeks will have measurements of arm length, MAC, proximal arm circumference, distal arm circumference, finger circumference to generate the conicity index. Receives: Other: Physical measurement; Other: Cuff size fitting |
What is being measured
The primary outcome is the main question the study is designed to answer.
Arm length (Left, Right)
The distance (cm) between the tip of the acromion process to the tip of the olecranon process on the posterior aspect of the arm, with the elbow in the flexed position.
Measured: During antenatal visit (1-2 hours). One visit only
Mid Arm circumference (MAC)(Left, Right)
The circumference (cm) of the arm at the mid-point of the arm length as measured above, with the arm hanging by the side.
Measured: During antenatal visit (1-2 hours). One visit only
Secondary outcomes (4)
Proximal arm circumference (Left, Right)
Arm circumference (cm) of the arm measured at the axilla, with the arm hanging by the side.
Measured: During antenatal visit (1-2 hours). One visit only
Distal arm circumference (Left, Right)
The circumference (cm) at the elbow above the elbow crease, with the arm hanging by the side.
Measured: During antenatal visit (1-2 hours). One visit only
Finger circumference (Left, Right)
The circumference (cm) of the mid-point of the middle phalanx of the middle finger will be measured with the hands placed flat on a table.
Measured: During antenatal visit (1-2 hours). One visit only
Feedback on experiences of previous BP measurement
Participants will also respond to a three-point rating scale (Never, sometimes, always) about their experience of the procedures for previous BP measurement during the current pregnancy, with questions such as the length of time taken to obtain a reading, the need to change a cuff when taking BP, the need to take BP on the leg and whether the arm felt uncomfortable when taking blood pressure.
Measured: During antenatal visit (1-2 hours). One visit only
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Jul 2019
- Study start10 Jul 2019
- Primary completion11 Dec 2019
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (13)Papers the sponsor has linked to this study.
- Other trials for Hypertension, Pregnancy-InducedStudies of the same condition, open and under way.
- More trials run by KK Women's and Children's HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 300 participants (actual)
Sponsor and investigators
- Lead sponsor
- KK Women's and Children's Hospital
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Sng Ban Leong, KK Women's and Children's Hospital
- Investigators
- Farida Ithnin, MMED (Anaes), Principal investigator, KK Women's and Children's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04012151
- Sponsor's protocol ID
- ARMFIN
- Other IDs
- ANAESPRG19/012
- Acronym
- ARMFIN
- Status last verified
- Aug 2026
- First submitted
- 27 May 2019
- Last updated
- 14 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
O'Brien E, Asmar R, Beilin L, Imai Y, Mallion JM, Mancia G, Mengden T, Myers M, Padfield P, Palatini P, Parati G, Pickering T, Redon J, Staessen J, Stergiou G, Verdecchia P; European Society of Hypertension Working Group on Blood Pressure Monitoring. European Society of Hypertension recommendations for conventional, ambulatory and home blood pressure measurement. J Hypertens. 2003 May;21(5):821-48. doi: 10.1097/00004872-200305000-00001. No abstract available.
PubMed 12714851Pickering TG, Hall JE, Appel LJ, Falkner BE, Graves J, Hill MN, Jones DW, Kurtz T, Sheps SG, Roccella EJ. Recommendations for blood pressure measurement in humans and experimental animals: part 1: blood pressure measurement in humans: a statement for professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research. Circulation. 2005 Feb 8;111(5):697-716. doi: 10.1161/01.CIR.0000154900.76284.F6.
PubMed 15699287Perloff D, Grim C, Flack J, Frohlich ED, Hill M, McDonald M, Morgenstern BZ. Human blood pressure determination by sphygmomanometry. Circulation. 1993 Nov;88(5 Pt 1):2460-70. doi: 10.1161/01.cir.88.5.2460. No abstract available.
PubMed 8222141Brown MA, Lindheimer MD, de Swiet M, Van Assche A, Moutquin JM. The classification and diagnosis of the hypertensive disorders of pregnancy: statement from the International Society for the Study of Hypertension in Pregnancy (ISSHP). Hypertens Pregnancy. 2001;20(1):IX-XIV. doi: 10.1081/PRG-100104165. No abstract available.
PubMed 12044323Penaz J. Criteria for set point estimation in the volume clamp method of blood pressure measurement. Physiol Res. 1992;41(1):5-10.
PubMed 1610779Palatini P, Parati G. Blood pressure measurement in very obese patients: a challenging problem. J Hypertens. 2011 Mar;29(3):425-9. doi: 10.1097/HJH.0b013e3283435b65. No abstract available.
PubMed 21317721Fonseca-Reyes S, de Alba-Garcia JG, Parra-Carrillo JZ, Paczka-Zapata JA. Effect of standard cuff on blood pressure readings in patients with obese arms. How frequent are arms of a 'large circumference'? Blood Press Monit. 2003 Jun;8(3):101-6. doi: 10.1097/00126097-200306000-00002.
PubMed 12900586Bonso E, Saladini F, Zanier A, Benetti E, Dorigatti F, Palatini P. Accuracy of a single rigid conical cuff with standard-size bladder coupled to an automatic oscillometric device over a wide range of arm circumferences. Hypertens Res. 2010 Nov;33(11):1186-91. doi: 10.1038/hr.2010.146. Epub 2010 Aug 5.
PubMed 20686489Palatini P, Benetti E, Fania C, Malipiero G, Saladini F. Rectangular cuffs may overestimate blood pressure in individuals with large conical arms. J Hypertens. 2012 Mar;30(3):530-6. doi: 10.1097/HJH.0b013e32834f98a0.
PubMed 22278143Kho CL, Brown MA, Ong SL, Mangos GJ. Blood pressure measurement in pregnancy: the effect of arm circumference and sphygmomanometer cuff size. Obstet Med. 2009 Sep;2(3):116-20. doi: 10.1258/om.2009.090017. Epub 2009 Sep 1.
PubMed 27582825Eley VA, Roberts L, Rickards L, Pelecanos A, Blackie A, Zhang C, Christensen R, Barrett HL. Arm and finger measurements in the third trimester: Implications for blood pressure measurement. Pregnancy Hypertens. 2018 Oct;14:105-109. doi: 10.1016/j.preghy.2018.09.002. Epub 2018 Sep 5.
PubMed 30527095Wang J, Thornton JC, Russell M, Burastero S, Heymsfield S, Pierson RN Jr. Asians have lower body mass index (BMI) but higher percent body fat than do whites: comparisons of anthropometric measurements. Am J Clin Nutr. 1994 Jul;60(1):23-8. doi: 10.1093/ajcn/60.1.23.
PubMed 8017333Lim MJ, Tan CW, Tan HS, Sultana R, Eley V, Sng BL. Correlation of patient characteristics with arm and finger measurements in Asian parturients: a preliminary study. BMC Anesthesiol. 2020 Aug 31;20(1):218. doi: 10.1186/s12871-020-01131-6.
PubMed 32867679
Study at a glance
From the registry record, last updated by the sponsor on 14 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Arm and Finger Measurement for Blood Pressure Surveillance
- ClinicalTrials.gov ID
- NCT04012151
- Acronym / sponsor ID
- ARMFIN / ARMFIN
- Conditions
- Hypertension, Pregnancy-Induced
- Keywords
- Blood pressure measurement, Conicity index, Mid arm circumference, Cuff size
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 300 participants (actual)
- Lead sponsor
- KK Women's and Children's HospitalOther government
- Study start
- 10 Jul 2019 (actual)
- Primary completion
- 11 Dec 2019 (actual)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 9 Jul 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Accurate blood pressure (BP) measurement is critical in peripartum care. The cuff and bladder sizes affects the accuracy of BP measurement. Current international BP measurement recommendations are based on mid-arm circumference (MAC). However, evidence have shown the discrepancies between these sizes, leading to inaccuracy of BP measurement. This study will measure arm and finger size of 300 parturients in third trimester to determine whether the MAC, finger measurement or body mass index (BMI) is the best clinical predictor for non-standard cuff sizes for BP measurement.
Detailed description
Accurate blood pressure (BP) measurement plays an important role in peripartum care as it is essential in detecting hypertensive disorders in pregnancy and medical decision making during the pregnancy. The cuff and bladder size have been highlighted as an important factor affecting the accuracy of BP measurement. Current international BP measurement recommendations are based on mid-arm circumference (MAC) assuming the arm is cylindrical in shape. However, evidence have shown a mismatch between these sizes, leading to BP overestimation or underestimation in obese patients. This is because the shape of the arm is a truncated cone instead of a cylinder, and the cuff will expand irregularly during inflation thus yielding inaccurate BP measurements. This is especially evident in Asian pregnant patients whereby no available guideline can recommend a suitable cuff for parturients with different MAC. Nexfin is a finger cuff device that can be a suitable alternative BP measurement device for such patients. In this study 300 parturients will be recruited in third trimester and undergoing nonemergent caesarean section in KKH. Patients' arm and finger sizes will be measured, and their user experience on current practices on BP measurement. The arm measurements will help to identify the proportion of women that may require non-standard cuff sizes for BP measurement. A conicity index will be determined whether the MAC, finger measurement or BMI is the best clinical predictor. The finger measurements will also help to determine the proportion of women that may require non-standard cuff sizes on the Nexfin device for BP measurement. The knowledge gathered in this pilot study will be used to design future studies in which the accuracy of Nexfin will be compared with standard BP measurement, which in turn will improve BP detection, subsequent patient monitoring and satisfaction.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Pregnant cohort | – | Other: Physical measurement, Other: Cuff size fittingParturients of gestational age >= 32 weeks will have measurements of arm length, MAC, proximal arm circumference, distal arm circumference, finger circumference to generate the conicity index. |
Who may qualify
- Ages
- 21 to 50 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- Pregnant women in Singapore
Key inclusion criteria (4 listed)
- American Society of Anaesthesiologists physical status 1 or 2 (ASA 1 or 2) parturients at 32 or more weeks of gestation
- Multiparous or nulliparous;
- Age 21-50 years old;
- Undergoing Caesarean section in our institution.
Key exclusion criteria (1 listed)
- Emergent Caesarean section such that consent and measurements cannot be taken.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Physical measurementAlso: Measurement of fingers and armsParturients of gestational week >= 32 weeks will have their arms and fingers measured to generate the conicity index. | Other | Pregnant cohort |
| Cuff size fittingAlso: Cuff fitting for arm and fingerFit on arm cuff and finger cuff as selected by investigators based on the measurement. | Other | Pregnant cohort |
Primary outcome
Arm length (Left, Right)
Time frame: During antenatal visit (1-2 hours). One visit only
The distance (cm) between the tip of the acromion process to the tip of the olecranon process on the posterior aspect of the arm, with the elbow in the flexed position.
Mid Arm circumference (MAC)(Left, Right)
Time frame: During antenatal visit (1-2 hours). One visit only
The circumference (cm) of the arm at the mid-point of the arm length as measured above, with the arm hanging by the side.
4 secondary outcomes
Proximal arm circumference (Left, Right)
Time frame: During antenatal visit (1-2 hours). One visit only
Distal arm circumference (Left, Right)
Time frame: During antenatal visit (1-2 hours). One visit only
Finger circumference (Left, Right)
Time frame: During antenatal visit (1-2 hours). One visit only
Feedback on experiences of previous BP measurement
Time frame: During antenatal visit (1-2 hours). One visit only
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Aug 2026.
- Background: PubMed 12714851O'Brien E, Asmar R, Beilin L, Imai Y, Mallion JM, Mancia G, Mengden T, Myers M, Padfield P, Palatini P, Parati G, Pickering T, Redon J, Staessen J, Stergiou G, Verdecchia P; European Society of Hypertension Working Group on Blood Pressure Monitoring. European Society of Hypertension recommendations for conventional, ambulatory and home blood pressure measurement. J Hypertens. 2003 May;21(5):821-48. doi: 10.1097/00004872-200305000-00001. No abstract available.
- Background: PubMed 15699287Pickering TG, Hall JE, Appel LJ, Falkner BE, Graves J, Hill MN, Jones DW, Kurtz T, Sheps SG, Roccella EJ. Recommendations for blood pressure measurement in humans and experimental animals: part 1: blood pressure measurement in humans: a statement for professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research. Circulation. 2005 Feb 8;111(5):697-716. doi: 10.1161/01.CIR.0000154900.76284.F6.
- Background: PubMed 8222141Perloff D, Grim C, Flack J, Frohlich ED, Hill M, McDonald M, Morgenstern BZ. Human blood pressure determination by sphygmomanometry. Circulation. 1993 Nov;88(5 Pt 1):2460-70. doi: 10.1161/01.cir.88.5.2460. No abstract available.
- Background: PubMed 12044323Brown MA, Lindheimer MD, de Swiet M, Van Assche A, Moutquin JM. The classification and diagnosis of the hypertensive disorders of pregnancy: statement from the International Society for the Study of Hypertension in Pregnancy (ISSHP). Hypertens Pregnancy. 2001;20(1):IX-XIV. doi: 10.1081/PRG-100104165. No abstract available.
- Background: PubMed 1610779Penaz J. Criteria for set point estimation in the volume clamp method of blood pressure measurement. Physiol Res. 1992;41(1):5-10.
- Results publication: PubMed 21317721Palatini P, Parati G. Blood pressure measurement in very obese patients: a challenging problem. J Hypertens. 2011 Mar;29(3):425-9. doi: 10.1097/HJH.0b013e3283435b65. No abstract available.
- Results publication: PubMed 12900586Fonseca-Reyes S, de Alba-Garcia JG, Parra-Carrillo JZ, Paczka-Zapata JA. Effect of standard cuff on blood pressure readings in patients with obese arms. How frequent are arms of a 'large circumference'? Blood Press Monit. 2003 Jun;8(3):101-6. doi: 10.1097/00126097-200306000-00002.
- Results publication: PubMed 20686489Bonso E, Saladini F, Zanier A, Benetti E, Dorigatti F, Palatini P. Accuracy of a single rigid conical cuff with standard-size bladder coupled to an automatic oscillometric device over a wide range of arm circumferences. Hypertens Res. 2010 Nov;33(11):1186-91. doi: 10.1038/hr.2010.146. Epub 2010 Aug 5.
- Results publication: PubMed 22278143Palatini P, Benetti E, Fania C, Malipiero G, Saladini F. Rectangular cuffs may overestimate blood pressure in individuals with large conical arms. J Hypertens. 2012 Mar;30(3):530-6. doi: 10.1097/HJH.0b013e32834f98a0.
- Results publication: PubMed 27582825Kho CL, Brown MA, Ong SL, Mangos GJ. Blood pressure measurement in pregnancy: the effect of arm circumference and sphygmomanometer cuff size. Obstet Med. 2009 Sep;2(3):116-20. doi: 10.1258/om.2009.090017. Epub 2009 Sep 1.
- Results publication: PubMed 30527095Eley VA, Roberts L, Rickards L, Pelecanos A, Blackie A, Zhang C, Christensen R, Barrett HL. Arm and finger measurements in the third trimester: Implications for blood pressure measurement. Pregnancy Hypertens. 2018 Oct;14:105-109. doi: 10.1016/j.preghy.2018.09.002. Epub 2018 Sep 5.
- Results publication: PubMed 8017333Wang J, Thornton JC, Russell M, Burastero S, Heymsfield S, Pierson RN Jr. Asians have lower body mass index (BMI) but higher percent body fat than do whites: comparisons of anthropometric measurements. Am J Clin Nutr. 1994 Jul;60(1):23-8. doi: 10.1093/ajcn/60.1.23.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Farida Ithnin, MMED (Anaes) principal investigator
KK Women's and Children's Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Hypertension, Pregnancy-Induced, run by KK Women's and Children's Hospital at 1 site in Singapore.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 14 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Arm length (Left, Right) (time frame: During antenatal visit (1-2 hours). One visit only). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04012151, which also lists 13 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Aug 2026.