Clinical trial NCT04288479: Acute Effects of High Intensity Training in Pregnancy on Fetal Well-being and Blood Flow Distribution
Official title: Acute Effects of HIT on Fetal Well-being and Blood Flow Distribution - a Pilot Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Pregnancy
Keywords: Exercise
High Intensity Interval Training
Pregnancy Outcome
Placental Circulation
Fetal Blood
Heart Rate, Fetal
Lead sponsor: Norwegian University of Science and Technology
Sponsor class: OTHER
Collaborators: name: St. Olavs Hospital
First posted: 2020-02-28
Enrollment: 34
Sex: FEMALE
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention model description: before-after intervention effect measurement
Primary purpose: TREATMENT

Brief summary: Pregnant women are recommended to be physically active ≥150 min/week, but \<15% of Norwegian women attain this goal. Several well-designed studies on lifestyle interventions focusing primarily on exercise training in overweight/obese pregnant women have reported disappointing outcomes with regard to maternal glycemic control, gestational weight gain and infant outcomes. Low adherence to the training program was found to be a problem; the participants did not enjoy the exercise program and had difficulties scheduling time to exercise. Pregnant women also report that they are not sure what exercises are safe during pregnancy.

High intensity interval training (HIT), defined as short periods of intense activity separated by low-intensity breaks, has proved to induce superior improvements in insulin sensitivity and fitness compared with continuous moderate intensity training in individuals at increased risk for cardiometabolic diseases. Even short-term (6 weeks) HIT with brief (15-60 sec) work-bouts and a total time commitment of \<45 min per week, improves insulin sensitivity similar to that attained after 6 months of traditional endurance training.

HIT is feasible and enjoyable for individuals with low fitness level and with obesity.

HIT is therefore a highly potent intervention that elicits important changes in a range of clinically relevant health outcomes in reproductive-aged women.

This study will investigate fetal responses to a single bout of HIT. Preliminary data of the investigators suggest that HIT does not negatively influence fetal heart rate. Others have reported that uterine and umbilical blood flow are not changed during or following acute exercise. However, no previous study has determined the acute effect of HIT on uterine blood flow and there are no studies investigating the fetal blood flow distribution in response to exercise. Since the relative distribution of blood to the fetal liver is associated with newborn adiposity, fetal blood flow distribution in response to exercise can provide insight about the effect of maternal exercise on offspring health.


Eligibility criteria: Inclusion Criteria:

* pregnant, gestational week 22-36
* singleton fetus
* no known diseases
* capable of cycling on an ergometer bike

Exclusion Criteria:

* hypertension
* gestational diabetes mellitus
* any contraindication to exercise training

Primary outcomes:
measure: blood flow in fetal veins
timeFrame: 1 day
measure: blood flow in fetal arteries
timeFrame: 1 day
Secondary outcomes:
measure: maternal heart rate
timeFrame: 1 dag
measure: Fetal heart rate
timeFrame: 1 day
measure: Umbilical vein diameter
timeFrame: 1 day
measure: Maternal systolic blood pressure
timeFrame: 1 day
measure: Maternal diastolic blood pressure
timeFrame: 1 day
measure: Maternal body weight
timeFrame: 1 day
measure: Maternal height
timeFrame: 1 day
Other outcomes:
Locations:
city: Trondheim
country: Norway
facility: Dept Circulation and Medical Imaging, EXCAR Exercise Lab
Study officials:
affiliation: St Olavs Hospital, Dept of Obstetrics and Gynecology
name: Kjell Å Salvesen, md prof
role: STUDY_DIRECTOR
affiliation: Norwegian University of Science and Technology
name: Trine Moholdt, phd
role: PRINCIPAL_INVESTIGATOR
References: