Randomized Clinical Study of the Effects of Aerobic Water Exercise on Maternal Cardiovascular Adaptation to Pregnancy
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Enrollment
- 41
- Locations
- 1
- Primary Endpoint
- Cardiovascular capacity
Study Overview
Brief Summary
Objective: To assess the relationship between maternal cardiovascular capacity and aerobic water exercise during the gestational periods of hemodynamic overload. Study design: randomized clinical trial, with 41 healthy pregnant women assigned to one of two groups: Control and Water exercise. Maternal cardiovascular capacity (maximum oxygen consumption, cardiac output, stroke volume, heart rate and mean arterial pressure), physical performance (relative HR, treadmill speed and self-perceived exertion) and neonatal outcome (gestational age, weight, Apgar index and length of infant's hospitalization) were assessed. Means were evaluated by dependent and independent t-tests, and proportions by the chi-square method (p<0.05). Results: The control variables showed that the groups were homogeneous. Water exercise was associated with maintenance of VO2max, increase in stroke volume and cardiac output, and better performance on stress tests in the third trimester of gestation. No significant difference in neonatal variables was observed. Conclusion: Water exercise maintained cardiovascular capacity and performance under submaximal stress, and did not affect hemodynamic adaptation to gestation or neonatal outcome.
Detailed Description
INTRODUCTION
Significant hemodynamic changes take place during the short period of pregnancy, very often placing a major burden on the maternal cardiovascular system. Normal pregnancy is characterized by an increase in cardiac output (CO), stroke volume (SV), heart rate (HR) and blood volume, and decrease in arterial pressure and vascular resistance. Classic studies have demonstrated an increase of up to 50% in maternal CO during the second and third trimesters. These circulatory adaptations are responsible for supplying nutrients and oxygen to the placenta and the fetus.
The physiological changes that follow regular exercise improve training efficiency and performance, defining the concept of adaptation to exercise or aerobic training. Exercise causes the heart and lungs to be more efficient by increasing cardiovascular capacity or resistance. CO, SV and maximum oxygen consumption (VO2max) increase while HR and AP decrease. The importance of these effects on overall health has been recognized by the most outstanding medical and scientific groups. Therefore, regular exercise has been widely promoted and a large number of women decide to begin or continue to exercise during pregnancy.
This change in women's behavior has become a matter of concern among obstetricians and has important practical implications - is the maternal body apt to bear the hemodynamic burden of pregnancy in association with exercise stress? Studies on the effects of exercise on pregnancy are scarce and show conflicting results, probably due to differences in exercise frequency, intensity, type, duration, and gestational age at training initiation.
Aiming at standardizing exercise practice and thus promote materno-fetal health, the American College of Obstetricians and Gynecologists (ACOG) issued, in 1985, guidelines for exercise during pregnancy. In subsequent reviews, new recommendations were added, and water exercise during pregnancy was recommended.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Supportive Care
- Masking
- None
Eligibility Criteria
- Ages
- 15 Years to 26 Years (Child, Adult)
- Sex
- Female
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Low-risk (healthy) pregnant women
- •At 16-20 weeks of gestation
- •Seen at the Prenatal Care Service for Low-risk Pregnancies of Botucatu Medical School-UNESP
Exclusion Criteria
- •Twin pregnancy
- •Clinical or obstetric disorder contraindicating an exercise program
- •Withdrawal from prenatal care at our service
- •Loss to follow-up; and failure to attend three (or more) exercise sessions, which was considered non-compliance to the aerobic water exercise program
Outcomes
Primary Outcomes
Cardiovascular capacity
Time Frame: 39 weeks
Performed during prenatal visits at 16-20, 28-33 and 34-39 weeks. Cardiovascular capacity was evaluated by using a treadmill submaximal stress test, according to the protocol of Balke-Ware \& Bruce that requires five minutes on treadmill at fixed incline and constant individualized speed with AP and HR monitoring.
Secondary Outcomes
- Assessment of physical performance at stress testing; stress perception during testing(39 weeks)