At how many weeks into pregnancy does resting heart rate in pregnant women begin to increase?

Resting heart rate in pregnant women begins to increase around 2 to 5 weeks into pregnancy due to several physiological changes that occur as the body adapts to support the developing fetus. During early pregnancy, the body undergoes significant hormonal changes, particularly an increase in progesterone, which helps prepare the uterus for implantation and influences cardiovascular function.

These hormonal adjustments lead to an increase in blood volume to ensure adequate circulation to both the mother and the fetus. As a result, the heart must pump more blood, resulting in an elevated resting heart rate. This increase is part of the body's natural response to accommodate the heightened metabolic demands placed on the cardiovascular system early in pregnancy. Consequently, tracking resting heart rate can be an important indicator of these changes for expecting mothers.