OPTIMUM: Optimising titration and monitoring of maternal blood pressure

• Register: ISRCTN
• Last refreshed on: 28 August 2023
• Main ID: ISRCTN16018898
• Date of registration: 04/07/2016
• Prospective Registration: No
• Primary sponsor: University of Oxford Clinical Trials and Research Governance Team
• Public title: OPTIMUM: Optimising titration and monitoring of maternal blood pressure
• Scientific title: Blood pressure self­monitoring for the management of women during pregnancy with chronic hypertension: a feasibility study
• Date of first enrolment: 09/12/2015
• Target sample size: 160
• Recruitment status: Completed
• URL: https://www.isrctn.com/ISRCTN16018898
• Study type: Interventional
• Study design: Randomized; Interventional; Design type: Diagnosis, Complex Intervention, Management of Care, Active Monitoring (Treatment)
• Phase: Not Applicable

Countries of recruitment

England, United Kingdom

Contacts

• Name: Louise Pealing

Key inclusion & exclusion criteria

Inclusion criteria: 1. Women with chronic hypertension (defined as sustained diastolic BP=90 mmHg and/or systolic BP=140 mmHg, present at booking or before 20 weeks gestation, or receiving treatment outside pregnancy and/or at time of referral)
2. Recruited at booking­ 23+6 weeks gestation
3. Viable singleton pregnancy
4. Willing to be randomised
5. Able to give informed written consent
6. Aged 18 years and over
Exclusion criteria: 1. Unwilling to self­monitor
2. Insufficient understanding of the study
3. Confirmed super­imposed pre­eclampsia (as defined by the International Society for the Study of Hypertension in Pregnancy (ISSHP) 2014 statement) before recruitment

Age minimum:
Age maximum:
Gender: Female

Health Condition(s) or Problem(s) studied

Specialty: Reproductive health and childbirth, Primary sub-specialty: Reproductive health and childbirth (migration)
Pregnancy and Childbirth
Chronic hypertension in pregnancy

Intervention(s)

Pregnant women with chronic hypertension will be randomised 2:1 intervention to usual care using a secure web-based system, with allocation stratified for study site.

Control group: Participants receive usual antinatal care alone.

Intervention group: Participants receive usual antenatal care and blood pressure self-monitoring at home in the management of chronic hypertension during pregnancy. This involves women being asked to measure their own blood pressure once per day at the same time each day, taking two readings, using an automated blood pressure machine (microlife WatchBP home) validated for use in pregnancy and pre-eclampsia. They will be asked to measure their own blood pressure from time of enrolment until delivery. If women are admitted to hospital during their pregnancy they are asked to continue to monitor their own blood pressure if they are able and this is acceptable to them. Women will be asked to record these blood pressure readings in a diary and bring them to their antenatal consultations so that their clinical team can use them in making treatment decisions. Women will be given a protocol to follow advising how and when to contact for clinical advice in the event of recording any high or low blood pressure readings.

Participants in both groups attend antenatal visits at 20, 28 and 34 weeks gestation and 6 weeks postnatal for blood pressure monitoring and completion of questionnaires.

Added 16/06/2017:
In addition women with gestational hypertension will be asked to text or use a study App to submit their home blood pressure readings to the research team, but also retain the option of continuing to use the blood pressure diary to record these readings.

Primary Outcome(s)

1. Recruitment rate is determined at the end of the study period by recording the number of participants recruited per site per month, including as proportion of those who were approached and eligible
2. Loss to follow up is determined at the end of the study period by recording the number lost to follow-up after delivery/number of participants recruited
3. Withdrawal rate is determined at the end of the study period by recording the number of participants withdrawing consent/number of participants recruited
4. Adherence and persistence with BP self-monitoring protocol is determined as the proportion of intervention participants completing no home BP measurements (total and by week) at the end of the study period
5. Acceptability of randomisation is determined at the end of the study period by recoridng the proportion of participants citing randomisation as reason for non-participation and the proportion in usual care arm starting home BP monitoring post-randomisation

Secondary Outcome(s)

1. Blood pressure control measured using:
1.1. Highest systolic blood pressure recorded between randomisation and delivery, excluding day of delivery
1.2. Average systolic blood pressure recorded between randomisation and delivery, excluding day of delivery (calculated using trapezium method applied to area under the curve)
1.3. Proportion developing systolic BP >=150 mmHg, and diastolic BP >=100 mmHg, recorded between randomisation and delivery, excluding day of delivery
2. Antihypertensive medication adherence measured using:
2.1. MARS and BMQ questionnaire score differences measured at 20, 28 and 34 weeks gestation
2.2. Defined Daily Dose of oral antihypertensive medication measured at 20, 28 and 34 weeks gestation
3. Maternal outcomes including:
3.1. Morbidity or mortality (pre-eclampsia, eclampsia, intracranial haemorrhage/infarct, myocardial ischaemia/infarction, intubation, pulmonary oedema, hepatic dysfunction, acute kidney injury, neurological dysfunction other than stroke (altered GCS, blindness, hyperreflexia + clonus, severe headache +hyperreflexia, persistent visual scotoma), disseminated intravascular coagulation, HELLP syndrome (haemolysis, elevated liver enzymes, low platelets), placental abruption, post-partum haemorrhage), all assessed on final maternal discharge after delivery
3.2. Gestation at delivery (assessed at delivery)
3.3. Mode of delivery (assessed at delivery)
3.4. Indication for delivery (assessed at delivery
4. Perinatal outcomes including:
4.1. Neonatal mortality or stillbirth (assessed at time of death)
4.2. Neonatal morbidity (including admission to neonatal unit: LDC, HDU, ICU; respiratory distress syndrome, need for ventilator support) all assessed on discharge of infant
4.3. Prematurity and small-for-gestational-age (assessed at delivery)
5. Health resource use outcomes including:
5.1. Number and cost of clinical contacts (antenatal attendances to clinic and day unit) and admissions and their timing for out-of-range BP readings and all-causes (assessed on maternal discharge)

Continuous ethnography is conducted during the trial.

Qualitative and experiential outcomes
1. How self-monitored BP readings are used in the management of chronic hypertension during pregnancy. Focused ethnographic study observing antenatal clinic and DAU/MAU consultations (assessed throughout pregnancy)
2. The experiences of the participants and clinicians involved in the study, measured using validated antenatal and postnatal health questionnaires (STAI, EQ-5D-5L and Little’s) and semi-structured interviews with women and clinicians in the postnatal period

Secondary ID(s)

20090

Source(s) of Monetary Support

National Institute for Health Research

Ethics review

Status:
Approval date:
Contact:

Old ethics approval format; East Midlands – Nottingham 2 Research Ethics Committee, 28/10/2015, ref: 15/EM/0490 Substantial Amendment 1: REC approval: 27/09/2016, HRA approval: 06/10/2016 Substantial Amendment 2: REC approval: 20/12/2016, HRA approval: 20/12/2016

Results

• Results available: Yes
• Date Completed: 31/10/2018