Influence of pregnancy on clinical course and fetal outcome of women with hypertrophic cardiomyopathy

Objectives: To study clinical evolution of women with HCM during pregnancy, the influencing factors of gestation on natural course of HCM and the frequency of HCM in their children in early childhood. Methods: A prospective study was conducted in 35 women with HCM; there were 23 pregnant women (PG group) and 12 nonpregnant control patients (NP group), matched for age and functional class (FC). Clinical monthly evaluations were carried out and electrocardiogram and transthoracic echocardiography tests were performed. The offspring endpoints included stillbirth and prematurity rates and investigation of HCM during childhood. Results: No deaths occurred in either group. Cardiac arrhythmias were significantly (p < 0.05) more frequent in the NP group (33.3% vs. 13.4%), and no differences were observed between the groups (p > 0.05) in heart failure (30.3% vs. 16.6%) or ischemic stroke (4.3% vs. 8.3%) rates. In the PG group, required hospitalization for treatment of cardiac complication was more frequent (p=0.05) in patients with family history of HCM (71.4% vs. 25.0%). Cesarean section was performed in 12 (52%) patients, for obstetrical reasons; there were 7 (30.4%) premature babies and 1 (4.3%) neonatal death. One child was clinically diagnosed as having HCM, and his genetic study identified a mutation in the beta myosin heavy chain gene, located on chromosome 14. Conclusion: Heart failure is a frequent cardiac complication in women with HCM during pregnancy, particularly in patients with family history of the disease, but this did not influence the natural course of HCM. In one child, clinical examination allowed HCM identification during early childhood.