Acute Effects of High Intensity Training in Pregnancy on Fetal Well-being and Blood Flow Distribution

NCT04288479 | Completed

• 1 other identifier: 62993
• Study Type: interventional
• Target: 34
• Locations: 1 country
• Sites: 1

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.

Conditions

Pregnancy

Keywords

Exercise; High Intensity Interval Training; Pregnancy Outcome; Placental Circulation; Fetal Blood; Heart Rate, Fetal

Outcome Measures

Primary Outcomes (2)

• blood flow in fetal veins

  examined by Doppler ultrasound during 30 minutes

  1 day

• blood flow in fetal arteries

  examined by Doppler ultrasound during 30 minutes

  1 day

Secondary Outcomes (7)

• maternal heart rate

  1 dag

• Fetal heart rate

  1 day

• Umbilical vein diameter

  1 day

• Maternal systolic blood pressure

  1 day

• Maternal diastolic blood pressure

  1 day

Study Arms (1)

Doing a single HIT session in gestational week 22-36

EXPERIMENTAL

Behavioral: Single high-intensity interval training session

Interventions

Single high-intensity interval training session BEHAVIORAL

10 minutes warming up at low-to-moderate intensity, 8x30 seconds high intensity interval training with fetal heart rate measurement after each 30 second work-bout, 2 minutes recovery at low-to-moderate intensity. Continuous monitoring of maternal heart rate.

Also known as: HIT

Doing a single HIT session in gestational week 22-36

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

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

Sponsors & Collaborators

• Norwegian University of Science and Technology: lead
• St. Olavs Hospital: collaborator

Study Sites (1)

Dept Circulation and Medical Imaging, EXCAR Exercise Lab

Trondheim, Norway

Location

MeSH Terms

Conditions

Motor Activity

Condition Hierarchy (Ancestors)

Behavior

Study Officials

• Kjell Å Salvesen, md prof

  St Olavs Hospital, Dept of Obstetrics and Gynecology

  STUDY DIRECTOR

• Trine Moholdt, phd

  Norwegian University of Science and Technology

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: before-after intervention effect measurement

Study Record Dates

• First Submitted: February 26, 2020
• First Posted: February 28, 2020
• Study Start: February 23, 2022
• Primary Completion: April 23, 2025
• Study Completion: April 23, 2025
• Last Updated: May 21, 2025

Record last verified: 2025-05

Data Sharing

• IPD Sharing: Will not share

Locations

NO (1)