The short-term effects of using Brythm with healthy pregnant women

by Malika Felton

25th January 2019

High blood pressure affects 12-15% pregnancies in the UK and can be diagnosed as chronic hypertension, pregnancy-induced hypertension (PIH) or preeclampsia. Chronic hypertension is high blood pressure that was present before the pregnancy, whereas PIH is new high blood pressure presenting after 20 weeks of pregnancy. Preeclampsia is high blood pressure with additional proteinuria and the only cure for PIH or preeclampsia is to give birth. The conditions and high blood pressure can be managed using lifestyle changes and medication but investigating drug-free alternative treatments for high blood pressure is important, as many medications are not suitable to take while pregnant.

Malika Felton from the Brythm team is investigating the use of the Brythm App to lower blood pressure in women with PIH. The previous research which led to the creation of the Brythm App was conducted with men and therefore the first study of Malika’s PhD verified that the responses to slow and deep breathing were the same in females as the previous research found in males. The next step of the PhD research is to investigate whether pregnant women respond in the same way as non-pregnant women. During pregnancy the body changes as a response to the presence of the baby, for example the amount of blood pumped around the body is increased (known as cardiac output). These cardiovascular changes may lead to differences in the responses of pregnant women to slow and deep breathing using the Brythm App.

Women taking part in the project will attend the Cardiorespiratory Research Laboratory at Bournemouth University’s Lansdowne Campus (located in the town centre) on one occasion for approximately 1 ½ hours. They will use the Brythm App to breathe at different frequencies, in addition to a spontaneous ‘normal’ breathing protocol. There will be 5 different breathing protocols, which will all be 5-minutes in duration and a 5-minute break will be provided between each protocol. They will be asked to follow breathing frequencies of 4, 6 and 8 breaths per minute and a dynamic frequency determined by the App (average ~6.2 breaths per minute in non-pregnant females). These breathing frequencies span the optimal range found in non-pregnant females from the first PhD study. Normal breathing frequency is around 12 breaths per minute, so they will be breathing at around half the normal rate. This is not as difficult as you might think, because the reduction in breathing rate is compensated by increasing breathing depth, which the body does automatically.

During each breathing protocol non-invasive cardiovascular measurements will be made continuously. Heart rate will be monitored using a 3-lead ECG, and blood pressure measured using a ‘high-tech’ cuff around one finger. Respiratory flow will be measured using a face mask covering the nose and mouth, allowing unrestricted breathing through both. See below for an example of experimental set up, which might look a little daunting, but is actually very comfortable; in fact, some of our participants are so relaxed they nearly fall asleep during the protocols.

If you are currently pregnant and think you might like to take part in this project, please read the following inclusion/exclusion criteria and get in touch with Malika for more detailed study information:

  • You must be currently pregnant with your first pregnancy and be over 20 weeks gestation;
  • You must be carrying a singleton pregnancy (not twins, triplets, etc.);
  • You must be aged 18 or over and a non-smoker;
  • If you have a current medical diagnosis of any of the following conditions you will not be able to participate in the study;
    • Hypertension, pregnancy-induced hypertension or preeclampsia;
    • Cardiovascular or respiratory disease (e.g. asthma, bronchitis, COPD [chronic obstructive pulmonary disease]);
    • An allergy or reaction to the conducting gel used for the ECG.

If at any point you feel participation is not for you then you are free to withdraw from participating in the study at any time, without giving a reason, and this will not impact upon/adversely affect your treatment, care or access to other services.

Please contact Malika Felton on 01202 961845 or mfelton@bournemouth.ac.uk to request more information on the study and if you have any questions.


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