Clinical trial NCT04586283: Does Prone Position Alter Maternal Cardiorespiratory Status?
Official title: Does Maternal Prone Position Affect Maternal Cardiorespiratory Status or the Fetal Heart Rate?
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Pregnancy-Related Condition, Unspecified
Keywords: Maternal prone position
Cardiac output
Fetal heart rate
Cardiotocography
Maternal anxiety
Lead sponsor: University of Manchester
Sponsor class: OTHER
First posted: 2020-10-14
Enrollment: 21
Sex: FEMALE
Minimum age (years): 16
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention model description: Cohort study
Primary purpose: TREATMENT

Brief summary: During pregnancy women may need or choose to undergo physical therapies such as physiotherapy, massage or osteopathy. Recent findings from studies of mothers who had a stillbirth in late pregnancy found that the position in which women went to sleep in was linked to stillbirth, as was the frequency of day time naps. This link is thought to be due to changes in mother's blood flow from her heart when lying flat leading to changes in the amount of oxygen going to her baby. This raise concerns that spending extended periods laid flat could be detrimental to baby's health. However, it is not known whether lying flat for extended periods for physical therapies could also alter a baby's heart rate or levels of oxygen. One small study of 33 women from Brazil found that there were no differences in a mother's heart rate, blood pressure, oxygen saturation or baby's heart rate. But there were changes in mother's breathing rate and systolic blood pressure when a mother laid on her front. All the women reported feeling comfortable lying flat (on a bent surface). However, in this study women only spent 6 minutes in each position which is less than a woman would be expected to spend lying in a position for a session of physical therapy. The investigators plan a study to assess whether using a device to support a prone position (Anna cushion) would be associated with changes in mother's heart rate, blood pressure, breathing rate and blood oxygen levels and baby's heart rate. The investigators will also ask about mother's levels of comfort while she is laid in the prone position. The findings of this study will give an indication whether supporting a mother to lie in a prone position for physical therapies is safe and comfortable.

Detailed description: Women frequently experience lower-back or pelvic pain during pregnancy. This may lead to a need for physical therapies such as physiotherapy, osteopathy or massage in late pregnancy. Several case-control studies, and a recent individual patient data meta-analysis has demonstrated an association between going to sleep position and late stillbirth (a greater than 2-fold increased risk with going to sleep supine) and increased frequency of daytime naps. This is thought to be related to maternal haemodynamic changes when a mother lies supine in late pregnancy which decreases cardiac output and uterine blood flow. These changes are accompanied by alterations in fetal behaviour which are consistent with a reduction in oxygenation. This observation raises concerns that spending extended periods laid flat could be detrimental to baby's health. However, it is not known whether lying flat for extended periods for physical therapies could also alter a baby's heart rate or levels of oxygen. One small study of 33 women from Brazil which randomised the order of maternal positions found that there were no differences in a mother's heart rate, blood pressure, oxygen saturation or baby's heart rate between a supine, lateral and prone position (bent over a concave couch). However, there were observed changes in mother's breathing rate and systolic blood pressure when a mother laid on her front. Nevertheless, all the women reported feeling comfortable lying flat (on a bent surface). However, in this study women only spent 6 minutes in each position which is less than a woman would be expected to spend lying in a position for a session of physical therapy. Therefore, further work is required to determine whether spending extended periods laid prone is safe for mother and baby.

The co-investigator (Karli Büchling) has developed a cushion to support mothers in a prone position (Anna cushion). This study will investigate whether adopting this position supported by the cushion is associated with changes in mother's heart rate, blood pressure, breathing rate and blood oxygen levels and fetal heart rate as assessed by the cardiotocograph. The investigators will also ask about mother's levels of comfort while she is laid flat. The findings of this study will give an indication whether supporting a mother to lie in a prone position for physical therapies is safe and comfortable.

Eligibility criteria: Inclusion Criteria:

* Viable singleton pregnancy ≥28 weeks' gestation
* No fetal anomalies according to Fetal Anomaly Screening Programme definition
* Ability to give written informed consent
* Maternal Age \>16 years

Exclusion Criteria:

* Unable to read English (as the survey instruments are only available in English)
* Multiple pregnancy
* Pre-existing maternal cardiovascular or respiratory disease
* Fetal anomaly
* Contraindication to lying prone (severe pain etc.)
* Allergy to self-adhesive electrodes used for standard electrocardiography (ECG)
* Unable to give written informed consent

Primary outcomes:
measure: Maternal cardiac output at Baseline
timeFrame: At baseline
measure: Change in maternal cardiac output
timeFrame: After 30 minutes in prone position
Secondary outcomes:
measure: Maternal heart rate at baseline
timeFrame: At baseline
measure: Change in maternal heart rate
timeFrame: After 30 minutes in prone position
measure: Maternal respiratory rate
timeFrame: At baseline
measure: Change in maternal respiratory rate
timeFrame: After 30 minutes in prone position
measure: Maternal blood pressure
timeFrame: At baseline
measure: Change in maternal blood pressure
timeFrame: After 30 minutes in prone position
measure: Oxygen saturation
timeFrame: At baseline
measure: Change in oxygen saturation
timeFrame: After 30 minutes in prone position
measure: Fetal heart rate
timeFrame: Baseline
measure: Change in fetal heart rate
timeFrame: Afer 30 minutes in prone position
Other outcomes:
measure: Maternal Anxiety
timeFrame: Before the experimental protocol
measure: Maternal Anxiety
timeFrame: Immediately after the completion of the experimental protocol
measure: Maternal comfort as assessed by visual analogue scale
timeFrame: Before the experimental protocol
measure: Maternal comfort as assessed by visual analogue scale
timeFrame: Immediately after the completion of the experimental protocol
measure: Maternal comfort as assessed by self-reported questionnaire
timeFrame: Immediately after the completion of the experimental protocol
Locations:
city: Manchester
country: United Kingdom
facility: Manchester University NHS Foundation Trust
Study officials:
References: