Pregnancy has no effect on the rate of structural deterioration of bioprosthetic valves: long-term 18-year follow up results.

BACKGROUND AND AIM OF THE STUDY: Should cardiac valve replacement be required, a bioprosthetic valve (BPV) is generally recommended for female patients of childbearing age to avoid anticoagulation hazards. Whether pregnancy accelerates BPV degeneration, or not, remains the subject of debate. The study aim was to determine the long-term effects of repeat pregnancy on the rate of structural deterioration of BPVs. METHODS: Eighty-five female patients of childbearing age who underwent BPV replacement between 1986 and 2000 were allocated to two groups: group P (n = 49; mean age 25 +/- 6 years) who became pregnant (144 pregnancies), and group NP (n = 36; mean age 27 +/- 7 years) who never became pregnant. The general characteristics of both groups were comparable. Clinical and echocardiographic data were obtained annually for all subjects; the mean follow up for all patients was 8.5 +/- 3.8 years (range: 4.6-18.4 years). Group P received 59 (68% mitral) BPVs, while group NP received 45 (60% mitral). The majority of BPVs were Hancock II porcine bioprostheses. The end-point was freedom from redo valve replacement due to structural valve deterioration (SVD). RESULTS: No major maternal complications were encountered. A total of 144 pregnancies resulted in 114 live deliveries (79%). During the follow up period, 30 patients required reoperation for SVD (23 (46.9%) in group P; seven (19.4%) in group NP). The mean valve survival time for groups P and NP was 11.5 +/- 7 years and 13 +/- 9 years, respectively. A test of freedom from redo surgery for SVD in both groups demonstrated no significant differences between the P and NP groups (RR 1.8; 95% CI = 0.761-4.256; p = 0.18). Further analysis testing the potential effect of increased number of pregnancies on the duration to redo surgery among P group showed no effect. CONCLUSION: Up to 18 years' follow up of patients with a BPV and repeated pregnancy showed there to be no pregnancy-related accelerated degeneration of BPVs. In addition, fetal loss rates were most likely lower with the use of BPVs.