Association Between Parity and Subclinical Left Ventricular Dysfunction in Healthy Pregnant Women: A Prospective...

Pregnancy induces profound cardiovascular adaptations that may have cumulative effects with repeated pregnancies. However, the relationship between parity and subclinical myocardial dysfunction in healthy women remains unclear.

This prospective cross-sectional study enrolled 605 healthy pregnant women without cardiovascular disease or risk factors. All participants underwent comprehensive echocardiographic assessment including speckle-tracking-derived global longitudinal strain (GLS) analysis during the third trimester (28-32 weeks gestation). The relationship between parity and GLS was described using multivariable linear regression analysis, adjusting for age, body mass index and blood pressure. Participants were stratified into two groups (≥ 4 vs. < 4 pregnancies) for comparative analysis.

Mean age was 30.9 ± 7.2 years with mean parity of 3.8 ± 2.4 pregnancies. Despite preserved ejection fraction across all women (63.2% ± 4.7%), each additional pregnancy was associated with a 0.21-unit worsening in GLS independent of age (β = 0.21, 95% CI: 0.13-0.29, p < 0.001). Women with ≥ 4 pregnancies had significantly worse GLS compared to those with fewer pregnancies (-19.1% ± 2.5% vs. -20.5% ± 4.1%, p < 0.001). In multivariable linear regression, high parity remained independently associated with reduced GLS (β = 1.18, 95% CI: 0.52-1.84, p < 0.001) after adjusting for confounders. The effect was more pronounced in older women and those with shorter interpregnancy intervals (< 18 months).

Higher parity is independently associated with reduced myocardial strain detected by GLS despite preserved ejection fraction, demonstrating a continuous relationship with each additional pregnancy. While GLS values remain within physiological ranges for pregnancy, the shift toward lower values suggests cumulative haemodynamic effects that warrant further investigation.