Very rare.

Reminder: in utero the ductus arteriosus is crucial for maintaining the fetal circulation. 90 % of the ejection volume of the right ventricle flows through the ductus arteriosus, while the rest perfuses the pulmonary vascular bed due to the high resistances (unventilated alveoli, filled with amniotic fluid). The in utero closure of the ductus arteriosus causes the ejection into the pulmonary circulation of the entire stroke volume of the right ventricle, with as consequences:

• a dramatic increase of the pressure in the pulmonary arteries, the hypertrophy of their media and finally a fixed pulmonary hypertension
• an hypertyhrophy of the right ventricle with tricuspid valve insufficiency and a dilation of the right atrium
• a dilation of the Valsalva sinuses of the pulmonary valve resulting in either a stenosis or a significant regurgitation through this valve
• a destruction of the pulmonary valve (agenesis) with dilation of the pulmonary artery and airway compression (bronchomalacia)
• fetal congestive heart failure and anasarca

The cause of this premature closure is generally unknown, but the intake of NSAID's during pregnancy is described in some cases.

Anesthetic implications:

induction of a premature birth; depending on the consequences on the RV: major cyanosis (right-to-left atrial shunt), pulmonary arterial hypertension, cardiac failure.

References :

-        Gewillig M, Brown SC, De Catte L, Debeer A, Eyskens B, CosseyV, Van Schoubroeck D, VanHole C, Devlieger R.
Premature foetal closure of the arterial duct: clinical presentations and outcome.
European Heart Journal 2009; 30:1530–6

Updated: April 2021