Prenatal Exercise and Cardiovascular Health (PEACH) (PEACH)

Exercise and Neurovascular Function During Pregnancy

Maintenance of a healthy pregnancy depends on an appropriate adaptation and responsiveness of blood vessels, to ensure appropriate blood flow to the fetus during everyday stressors. Previous work by the investigators has demonstrated that during pregnancy, the part of the nervous system responsible for cardiovascular function (the sympathetic nervous system) is hyperactive. The investigators also know that in women who develop high blood pressure during pregnancy that sympathetic nervous system activity is even higher. Yet, very little is known about why this occurs and how this might be affected.

Pregnant women are encouraged to be active, yet, less than 15% of women perform sufficient exercise to meet current guidelines. This is important because hyperactivity of the sympathetic nervous system is observed in other inactive populations and has been linked to adverse cardiovascular health outcomes including hypertension, atherosclerosis, heart attack, and stroke. Indeed, in 2011, the American Heart Association stated that inactivity was a risk factor as potent as cigarette smoking for the development of future cardiovascular disease in women.

The investigators' work and others have demonstrated that exercise during pregnancy is beneficial for both the mom and baby; however, the effect of prenatal exercise on neurovascular function is not known. If exercise is effective in controlling the increase in sympathetic activity that occurs during pregnancy, or its effects on the cardiovascular system, this may help prevent the development of high blood pressure or other cardiovascular problems during pregnancy.

Study Overview

• Status: Unknown
• Conditions: Pregnancy
• Intervention / Treatment: Other: Aerobic exercise

Detailed Description

The objectives of this study are to: 1) examine the impact of exercise on sympathetic and vascular function during pregnancy; 2) examine the role of endothelial function on the vascular effects of exercise during pregnancy.

Study design:

100 women (>18yrs) will be recruited in the first or second trimester (<20 wks). Women with multiple pregnancies will be excluded. Eligible women will be randomized between an aerobic exercise intervention (EXER) or no intervention (CTRL).

Initial testing will take place between 16-20 weeks of pregnancy. Following initial baseline testing, women will be randomly assigned to an exercise intervention or no intervention. Women will receive an opaque sequentially numbered envelop with their allocation. Allocation will be determined using a randomly generated allocation sequence by an individual not associated with the research study. The intervention will consist of aerobic exercise equivalent to 50-70% of heart rate reserve, 3-4 times per week until the end of the study (34-36 weeks). For initial baseline testing (16-20 weeks) and at the end of the intervention (34-36 weeks), participants will visit the laboratory twice

On Day 1, participants will complete a peak exercise test on the treadmill or bike to volitional fatigue to measures fitness and cardiovascular/cerebrovascular responses to exercise.

On Day 2 Participants will arrive fasted (12 hrs) and blood samples will be collected. Anthropometrics, personal/familial history of hypertension and pregnancy complications will be recorded. Following a standardized breakfast, participants will undergo an assessment of reflex neurovascular control including a cold pressor test, flow mediated dilation and end expiratory voluntary breath hold. Muscle sympathetic nerve activity, ultrasound (blood flow and diameter of brachial, femoral and carotid arteries), blood pressure, heart rate and respiratory variables will be measured.

OUTCOME/IMPACT

Pregnancy is a stress-test for life; with women who develop complications during pregnancy having a higher risk for cardiovascular disease later in life. Exercise is well known to prevent cardiovascular disease through improvements in endothelial function and the sympathetic nervous system. Whether this improvements is also seen in pregnancy remains to be seen.

• Study Type: Interventional
• Enrollment (Anticipated): 100
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Margie Davenport, PhD; Phone Number: 780-492-0642; Email: mdavenpo@ualberta.ca
• Study Contact Backup: Name: Craig Steinback, PhD; Phone Number: 780-492-5553; Email: craig.steinback@ualberta.ca

Study Locations

• Canada
  • Alberta
    • Edmonton, Alberta, Canada, T6G 2E1
      • Recruiting
      • Program for Pregnancy and Postpartum Health, University of Alberta
      • Contact: Margie Davenport, PhD; Phone Number: 780-492-0642; Email: mdavenpo@ualberta.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• >18 years old
• singleton pregnancy
• cleared to exercise by health care provider using Par Med X for Pregnancy (CSEP)

Exclusion Criteria:

• multiple gestation
• absolute contraindication to exercise (CSEP)
• <18 years old
• develops any contraindication during intervention

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Exercise Intervention; The aerobic exercise intervention will consist of a walking program at 50-70% of individual heart rate reserve. This will begin at 16-20 weeks gestation and continue 3-4 times per week until the end of the study (34-36 weeks). The duration of exercise will increase each week up to a maximum of 40 minutes (5 min warm up, 25 minutes exercise, 5 min cool down). Women will have at least one supervised exercise session per week. The investigators will also monitor other activity using questionnaires and accelerometry. This will occur at baseline (16-20 weeks), mid-intervention (24-26 weeks) and at the end (34-36 weeks).	Other: Aerobic exercise; Brisk walking 3-4 times per week for up to 40 minutes of activity.; Other Names: walking program
No Intervention: Control Group; These women will continue regular daily activities. Activity will be monitored periodically with questionnaires and accelerometry. This will occur at baseline (16-20 weeks), mid-intervention (24-26 weeks) and at the end (34-36 weeks).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sympathetic Nerve Activity - cold pressor test response	Response of the sympathetic nervous system to cold pressor test (% change in activity)	16-20 weeks and 34-36 weeks gestation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Respiratory measures - respiratory frequency	Breathing frequency (breaths per minute). Measured using spirometry.	16-20 weeks and 34-36 weeks gestation
Sympathetic Nerve Activity - breath hold response	Response of the sympathetic nervous system to voluntary breath hold (% change in activity)	16-20 weeks and 34-36 weeks gestation
Respiratory measures - tidal volume	Tidal Volume (Liters per breath). Measured using spirometry.	16-20 weeks and 34-36 weeks gestation
Respiratory measures - oxygen	Oxygen metabolism (% oxygen used per breath). Measured using a gas analyzer.	16-20 weeks and 34-36 weeks gestation
Respiratory measures - carbon dioxide	Carbon Dioxide production (% carbon dioxide per breath). Measured using a gas analyzer.	16-20 weeks and 34-36 weeks gestation
Respiratory measures - lung volume	Total Lung Capacity (Liters). Measured using spirometry.	16-20 weeks and 34-36 weeks gestation
Cerebral blood flow at rest	Brain blood flow in the middle cerebral artery at rest (cm/s). Measured using transcranial doppler ultrasound.	16-20 weeks and 34-36 weeks gestation
Cerebral autoregulation	Brain blood flow in the middle cerebral artery in response to standing (cm/s). Measured using transcranial doppler ultrasound.	16-20 weeks and 34-36 weeks gestation
Cerebral blood flow during exercise	Brain blood flow in the middle cerebral artery during the acute incremental peak exercise test (cm/s). Measured using transcranial doppler ultrasound.	16-20 weeks and 34-36 weeks gestation
fasted blood sample - blood volume	Fasted blood samples (~30ml) will be analyzed for markers of blood volume (hematocrit; %)	16-20 weeks and 34-36 weeks gestation
fasted blood sample - neurotransmitters	Fasted blood samples (~30ml) will be analyzed for sympathetic nervous system neurotransmitters (Norepinephrine, Epinephrine, Neuropeptide-Y).	16-20 weeks and 34-36 weeks gestation
fasted blood sample- inflammatory markers	Fasted blood samples (~30ml) will be analyzed for inflammatory markers (i.e. C-Reactive Protein).	16-20 weeks and 34-36 weeks gestation
fasted blood sample- epigenetics	Fasted blood samples (~30ml) will be analyzed for epigenetics (optional).	16-20 weeks and 34-36 weeks gestation
fasted blood sample- sex hormones	Fasted blood samples (~30ml) will be analyzed for sex hormones (estrogen, progesterone, testosterone).	16-20 weeks and 34-36 weeks gestation
fasted blood sample- metabolic	Fasted blood samples (~30ml) will be analyzed for metabolic parameters (i.e. glucose)	16-20 weeks and 34-36 weeks gestation
fetal outcomes- birth weight	Participants will provide the investigators with birth weight for the infant (grams).	within one month postpartum
fetal outcomes- length	Participants will provide the investigators with birth length for the infant (cm).	within one month postpartum
fetal outcomes- gestational age	Participants will provide the investigators with gestational age at delivery (weeks).	within one month postpartum
maternal outcomes- mode of delivery	Participants will provide the investigators with mode of delivery (vaginal or cesarean).	within one month postpartum
maternal outcomes- delivery complications	Participants will provide the investigators with information regarding any delivery complications.	within one month postpartum
maternal outcomes- pregnancy complications	Participants will provide the investigators with information regarding any pregnancy complications (gestational diabetes, pregnancy induced hypertension, preeclampsia).	any time during study
fetal outcomes- apgar score	Participants will provide the investigators with APGAR scores (out of 10) for the infant	within one month postpartum
fetal outcomes- NICU	Participants will provide the investigators with information regarding length (days) of admission to Neonatal Intensive Care Unit (NICU) if applicable.	within one month postpartum
maternal outcomes- gestational weight gain	Participants will provide the investigators with the last maternal weight immediately before delivery. This will be used to calculate gestational weight gain (kg; last maternal weight - self reported pre-pregnancy weight).	within one month postpartum
Endothelial Function - time to peak dilation	The investigators will assess endothelial function using flow mediated dilation (FMD, time to maximal dilation; s)	16-20 weeks and 34-36 weeks gestation
Endothelial Function- flow mediated dilation	The investigators will assess endothelial function using flow mediated dilation (change in diameter; mm)	16-20 weeks and 34-36 weeks gestation
Endothelial Function - shear stress	The investigators will assess endothelial function using flow mediated dilation (shear stress; pascals).	16-20 weeks and 34-36 weeks gestation
Accelerometry	The investigators will objectively measure physical activity using an accelerometer for one week. Average number of minutes per day spent in various activity levels will be determined.	16-20 weeks and 34-36 weeks gestation
Physical Activity Questionnaire	The participants will report physical activity using the pregnancy physical activity questionnaire (gives metabolic equivalent hours per week (MET-hr/week).	16-20 weeks and 34-36 weeks gestation
Depression rating	Participants will answer a 10-question questionnaire regarding their mood. A score of 10 or higher is indicative of depressive symptoms. The investigators will report the over number of women in each group who have a score of 10+ at the start and end of the intervention.	16-20 weeks and 34-36 weeks gestation
Sleep Quality	Participants will report their sleep quality using the Pittsburgh Sleep Quality index. A score of 5 or more indicates poor sleep quality. The investigators will compare this score between groups before and after the intervention.	16-20 weeks and 34-36 weeks gestation
Food log	The investigators will objectively measure nutrients in diet using a three day food record. This is completed through Food Prodigy/ Food Processor software.	16-20 weeks and 34-36 weeks gestation

Collaborators and Investigators

• Sponsor: University of Alberta, Physical Education
• Investigators: Study Director: Rachel Skow, MSc, University of Alberta

Publications and helpful links

General Publications

• Boparai R, Skow RJ, Farooq S, Steinback CD, Davenport MH. Prenatal exercise and cardiovascular health (PEACH) study: the remote effect of aerobic exercise training on conduit artery and resistance vessel function. Appl Physiol Nutr Metab. 2021 Dec;46(12):1459-1468. doi: 10.1139/apnm-2020-0902. Epub 2021 Jun 23.
• Skow RJ, Fraser GM, Steinback CD, Davenport MH. Prenatal Exercise and Cardiovascular Health (PEACH) Study: Impact on Muscle Sympathetic Nerve (Re)Activity. Med Sci Sports Exerc. 2021 Jun 1;53(6):1101-1113. doi: 10.1249/MSS.0000000000002583.

Study record dates

Study Major Dates

• Study Start: July 1, 2016
• Primary Completion (Anticipated): August 1, 2019
• Study Completion (Anticipated): December 1, 2019

Study Registration Dates

• First Submitted: July 13, 2016
• First Submitted That Met QC Criteria: October 27, 2016
• First Posted (Estimate): October 28, 2016

Study Record Updates

• Last Update Posted (Actual): May 7, 2018
• Last Update Submitted That Met QC Criteria: May 4, 2018
• Last Verified: May 1, 2018

More Information

Terms related to this study

• Keywords: exercise; pregnancy; cardiovascular; nervous system
• Other Study ID Numbers: Pro00061045

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No