Spontaneous haemothorax caused by a ruptured pulmonary arterio-venous malformation: A manifestation of hereditary haemorrhagic telangiectasia in pregnancy.

We report our experience of managing a massive haemothorax caused by a ruptured, previously unknown, pulmonary arteriovenous malformation (pAVM) at 34 + 5 weeks of gestation, which proved to be a manifestation of hereditary haemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome. The patient underwent an emergency caesarean section under general anaesthesia after placement of a chest tube and gave birth to a healthy infant. A postoperative thoracic computed tomography angiography highlighted the presence of the large pAVM. Transcatheter embolization was performed right after the delivery. Subsequent patient's anamnesis, family history and genetic analysis finally revealed the presence of the syndrome. The aim of our report is to create awareness of this serious condition with potential life-threatening complications, especially in pregnancy. Simple criteria have been published and allow to easily consider HHT and the presence of potential AVM during anamnesis, ideally even before pregnancy.