Pregnancy increases cardiac output and may exacerbate left ventricular outflow tract (LVOT) gradients, particularly in women with pre-existing LVOT obstruction (LVOTO). This retrospective observational study published in the International Journal of Cardiology evaluated clinical and echocardiographic outcomes in women with LVOTO before, during, and after pregnancy between 2009 and 2023 at two tertiary centers. 

Data were collected preconception, antenatally, and postpartum. Key parameters included peak and mean LVOT gradients, aortic valve area, and left ventricular ejection fraction. The primary endpoint was the need for postpartum intervention; secondary endpoints included a composite of adverse clinical outcomes and postpartum intervention.

Seventy-eight women with LVOTO (109 pregnancies) were included. Gestational increases in LVOT gradients were observed but were transient in most cases, regressing to baseline postpartum. Postpartum intervention was required in 11% of pregnancies, occurring at a median of 6.3 (4.4–9.2) years. Baseline LVOTO severity (HR = 29.6; p<0.01), antenatal severity (HR = 21.1; p<0.01), and postpartum severity (HR = 18.3; p<0.01) were associated with the primary endpoint. Women with severe LVOTO preconception (10%) had a higher risk of postpartum intervention, whereas transient antenatal severity alone was not associated with increased risk.

Pregnancy-related LVOT gradient increases were generally reversible postpartum. Severe preconception LVOTO, rather than transient gestational changes, was associated with later intervention risk.