“…Systemic vascular resistance (SVR) decreases, and aortocaval compression by the gravid uterus can lead to reduced venous return, cardiac output, and uterine blood flow. 22,23 These physiologic changes can precipitate arrhythmias, heart failure, and cardiovascular events that require urgent invasive intervention. 21,24 Risks to the fetus include poor maternal functional status before pregnancy or maternal cyanosis, left heart obstruction (see below), maternal age below 20 and above 35 years, maternal smoking, and treatment with anticoagulants.…”