When should pregnant women avoid exercising in the supine position?

Pregnant women are generally advised to avoid exercising in the supine position after week 16 of gestation. This recommendation is based on the physiological changes that occur during pregnancy, particularly the effects of the growing uterus on blood flow. When a pregnant woman lies on her back, especially after 16 weeks, the weight of the uterus can compress the inferior vena cava, leading to reduced venous return to the heart. This may result in decreased cardiac output, hypotension, and reduced blood flow to the fetus, potentially causing dizziness, shortness of breath, and other complications for the mother.

As the pregnancy progresses, the risk of these complications can increase, making it imperative to modify exercises accordingly. Thus, the guideline to avoid supine exercises after this period is aimed at ensuring the safety of both the mother and the developing fetus. It is essential for healthcare providers and exercise professionals to educate pregnant women on safe exercise practices throughout their pregnancy.