Exercise During Pregnancy and Its Benefits

Fetal Effects of Exercise During Pregnancy: Effects on Fetal Heart Rate, Uterine Blood Flow, and Fetal Blood Flow

Fetal heart rate can vary depending on the intensity, duration, and type of exercise. Fetal heart rate may increase by 5-15 beats/min during exercise. The fetal heart rate returns to normal within 5-20 minutes after exercise. This increase is not harmful to the fetus. Episodes of fetal bradycardia are uncommon unless there are obstetric or medical complications. Uterine blood flow may decrease by 20-60% during exercise. It returns to normal within 20 minutes after exercise. Increased maternal hematocrit and increased blood oxygen-carrying capacity compensate for fetal blood flow. Therefore, studies have found that exercise has little, if any, effect on fetal blood flow, while others have no effect at all.1-3 Decreased uterine blood flow has been shown in women living at high altitudes. Women living at altitudes exceeding 2500 meters are advised to avoid strenuous physical exertion for at least 4-5 days.

The Effect of Exercise on Pregnancy Duration

It has been thought that increased norepinephrine and prostaglandins during exercise may stimulate preterm labor by increasing uterine activity. However, one study found no increased risk of exercise-related preterm labor, premature rupture of membranes, or fetal distress.

Effect of Exercise on Birth Weight

Some studies on exercise during pregnancy have found a decrease in birth weight. It has been shown that when pregnant women increase their exercise levels by more than 50% compared to pre-conception levels, birth weight decreases significantly. Another study comparing pregnant women who engage in vigorous exercise with those who lead sedentary lifestyles found no difference in birth weight. Some studies have shown that women who exercise at a level that burns 2000 kcal per week have babies with higher birth weights than women who do not exercise.

Benefits of Exercise During Pregnancy

Exercise provides both physical and psychological benefits during pregnancy. Fatigue, varicose veins, and leg swelling, which are common during pregnancy, are reduced through exercise. Furthermore, forgetfulness, stress, anxiety, and depression are less common in pregnant women who exercise. Excessive weight gain during pregnancy and the inability to lose it for the first six months postpartum can lead to long-term obesity. Exercise and a balanced diet ensure desired weight gain during pregnancy. Some studies have found that moderate weight gain through exercise during pregnancy reduces labor time and birth complications. Epidemiological studies, particularly in morbidly obese women, have found exercise to be beneficial in preventing gestational diabetes. The American Diabetes Association has approved exercise as an adjunct treatment for patients with gestational diabetes who cannot maintain glycemic control through diet. Exercise helps regulate the muscle activity required for labor, reduces birth complications, and reduces the rate of cesarean sections and the need for analgesics. If women continue exercising during pregnancy during the postpartum period, postpartum recovery is accelerated. It helps maintain body shape and increases self-confidence. Stress, anxiety, and depression are reduced. Hypertension and preeclampsia are less common in active women. It regulates circulatory and digestive functions. Physical conditioning can be maintained more easily, increasing resistance to fatigue. Postural disorders can be prevented. It reduces back and waist pain, leg cramps, varicose veins, and edema. Exercise protects against obesity, coronary heart disease, osteoporosis, and hypertension, while also reducing the risk of colon and breast cancer. In the lipid profile, it lowers LDL cholesterol and triglycerides while raising HDL cholesterol. It also improves sleep disorders. All of these changes reduce complications that may occur during pregnancy and help deliver a healthy baby.

Before Exercise Is Recommended to Pregnant Women

The pregnant woman should be evaluated overall, and her medical and obstetric status should be reviewed. Conditions that constitute contraindications to exercise should be identified, and the individual's previous activity status should be reviewed. Adequate information about exercise programs, their potential risks, and their implementation should be obtained. The feasibility of implementing the proposed program should be considered.