From the Guidelines
Normal pulmonary artery pressure (PAP) during pregnancy remains similar to non-pregnant values, with a mean PAP of less than 20 mmHg considered normal, as indicated by the most recent and highest quality study 1.
Normal Pulmonary Artery Pressure Values
Specifically, normal values include:
- Systolic PAP of 15-30 mmHg
- Diastolic PAP of 4-12 mmHg
- Mean PAP of 9-18 mmHg These values are based on the understanding that normal mean pulmonary arterial pressure at rest is 14 to 20 mmHg, as stated in the 2017 study 1.
Adaptation During Pregnancy
Despite the significant cardiovascular changes that occur during pregnancy, including increased blood volume and cardiac output, the pulmonary circulation maintains relatively stable pressures due to pregnancy-induced pulmonary vasodilation and increased pulmonary vascular compliance. This adaptation helps accommodate the 30-50% increase in cardiac output without causing pulmonary hypertension.
Importance of Monitoring
Monitoring PAP may be important in pregnant women with pre-existing cardiac or pulmonary conditions, as elevated pulmonary pressures (pulmonary hypertension) during pregnancy are associated with significant maternal morbidity and mortality, as discussed in earlier studies 1. Any persistent elevation above these normal values during pregnancy warrants further evaluation.
From the Research
Normal Pulmonary Artery Pressure in Pregnancy
- The normal pulmonary artery pressure is generally considered to be below 20 mmHg at rest, as stated in studies 2, 3.
- However, it's essential to note that pulmonary hypertension is defined by a mean pulmonary artery pressure of more than 20 mmHg at rest or 25 mmHg at rest or 30 mmHg with exercise, according to 4.
- In the context of pregnancy, the definition of normal pulmonary artery pressure is crucial, as pulmonary hypertension can have severe implications for both mother and child.
- Studies 2, 3, 5, 4 emphasize the importance of careful monitoring and management of pregnant women with pulmonary hypertension due to the high risk of maternal and fetal morbidity.
Pulmonary Artery Pressure Measurements
- The systolic pulmonary artery pressure (sPAP) estimated by transthoracic echocardiography can be used to assess pulmonary artery pressure, as seen in study 6, which reported an average sPAP of (95.6 ± 1.3) mmHg in pregnant women with severe idiopathic pulmonary arterial hypertension.
- Hemodynamic measurements, such as those obtained through right-heart catheterization, can also provide valuable information on pulmonary artery pressure, as mentioned in 2.
Clinical Implications
- Pregnant women with pulmonary hypertension require close monitoring and individualized care, as highlighted in studies 2, 3, 5, 4.
- The management of pulmonary hypertension during pregnancy should involve a multidisciplinary approach, including preconception counseling, antenatal care, and post-partum management, as emphasized in 2, 5, 6.