Final answer:
Maternal exercise can indirectly affect fetal heart rate due to changes in maternal cardiac output and blood flow to the placenta. Excessive or sustained contractions during exercise may lead to fetal distress and a need for emergency birth interventions. Fetal heart rates change with age, starting at around 120 bpm in newborns and adjusting as the individual grows.
Step-by-step explanation:
During maternal exercise, the fetal heart rate (HR) may experience changes. Exercise impacts the maternal cardiovascular system, which can indirectly influence the fetal circulation. When a pregnant woman exercises, her heart rate and cardiac output increase to meet the higher metabolic demands. In turn, this can affect the blood flow to the placenta and indirectly impact the fetal heart rate.
It is important to note that each contraction of the pregnant woman's heart can reduce oxygenated blood flow to the fetus temporarily. Consequently, after each contraction, a period of relaxation is essential to allow for the restoration of oxygenated blood to the fetal circulation. If contractions are too strong or sustained, there can be a significant decrease or increase in fetal heart rate, which is a sign of fetal distress. This condition might necessitate an emergency birth intervention such as vacuum, forceps, or a Caesarian section.
Moreover, fetal heart rates also vary with the fetus's age. While a newborn's resting heart rate may be around 120 bpm, this rate decreases until young adulthood and then increases again with age. The exact effects of exercise on the fetal heart rate can vary and should be monitored by a healthcare professional during pregnancy to ensure the safety of both the mother and the fetus.