Why should pregnancy affect HHT?
During pregnancy the circulating blood may increase by as much as 60%, which is normal and essential for the development of the baby. This means fragile blood vessels may be more prone to bleed. The body copes with this extra blood by making many of the mothers blood vessels dilate, and these do not always return to their pre-pregnancy size. In spite of this, the majority of HHT pregnancies are safe for the mother with HHT and for the baby. Are particular families more at risk of pregnancy-related complications? You are probably aware that HHT affects members of you family in different ways, even though everyone with HHT in any one particular family will have the same genetic defect. This suggests that factors other than the mutated gene contribute to how HHT develops in any one individual, and this includes pregnancy-related complications. When we looked at a series of 161 HHT pregnancies, 11 women had significant complications. Importantly, all except one of these women had close fem
