Medical complications of pregnancy in hereditary haemorrhagic telangiectasia.

Hereditary haemorrhagic telangiectasia (HHT) displays significant variation in severity between affected individuals in the same family, ranging from relatively trivial epistaxis and telangiectasia to gastrointestinal, cerebral and pulmonary involvement. Evidence for successful therapy of HHT-related haemorrhage with oestrogens and progesterones, and recent case reports outlining pulmonary complications of pregnancy in HHT, prompted us to review the outcome of 161 pregnancies in 47 affected women. HHT-related maternal complications developed in eleven patients, ten in the subgroup of 23 pregnancies in which pulmonary arteriovenous malformations (PAVMs) were present at the outset, or documented in the two years following pregnancy. We present six cases of intrapulmonary shunt deterioration, two cases of fatal pulmonary haemorrhage and three cerebrovascular accidents related to pregnancy. A predisposition towards PAVMs in females was observed. Following the recent discovery of mutations in the endoglin gene in this disease, our data support a hypothesis of hormonal modification of the HHT phenotype. In addition, a significant excess of affected offspring are present in HHT families. We consider contributary aetiological factors, and discuss implications for patient management.