Effect of pregnancy on the duration of bovine pericardial bioprostheses

This study sought to evaluate the effect of pregnancy on the rate of deterioration of bovine pericardial bioprostheses. To avoid the fetal and maternal risks associated with anticoagulant therapy during pregnancy, the use of bioprostheses has been advocated for young women with cardiac valve disease who may later wish to bear children. Several reports have suggested the probability of pregnancy-related accelerated deterioration of these valves.

The incidence of prosthetic dysfunction and the freedom from deterioration were investigated in 48 women who had 58 pregnancies and in a control group of 167 patients in the same age range. There were 39 cases of prosthetic dysfunction (deaths plus reoperations resulting from valve failure): 12 in the pregnant group for a linearized rate of 3.5% +/- 0.99% (SE) per patient-year and 27 in the control group or 3.4% +/- 0.65% per patient-year (P = not significant). The actuarial freedom from dysfunction was 90.4% (95% confidence interval 77.9 to 96.2) at 5 years and 77.0% (59.7 to 88.3) at 8 years for the pregnancy group and 86.3% (77.3 to 92.0) and 73.4% (56.6 to 84.8), respectively, for the control group ( P = not significant). In the Cox proportional hazard regression analysis, pregnancy did not influence dysfunction. A direct correlation was found between freedom from dysfunction and the patient's age at surgery.

Pregnancy does not accelerate the rate of deterioration of bovine pericardial bioprostheses. It is more likely that biological valves deteriorate more rapidly in these patients because of their young age.