Agenesis of inferior vena cava in pregnancy: A case report and narrative review.

Agenesis of inferior vena cava (AIVC) is an extremely rare congenital abnormality. In AIVC, venous flow from the lower extremities enter superior vena cava mainly through the azygous and hemiazygous system, forming anastomotic collateral vessels. A global increase in intra-abdominal pressure by the gravid uterus may further stress the collateral system, increase venous stasis and decrease venous return. We present the management of a 37-year old pregnant woman with AIVC who underwent caesarean section with norepinephrine infusion and general anaesthesia. She presented with shortness of breath when seated, episodes of dizziness while walking or sitting upright with subsequent tachycardia. Cardiac status was monitored using an arterial pulse contour CO monitor. We did not observe large fluctuations in CO, SV, MAP during induction and intubation as well as during delivery. We believe that administration of an infusion of norepinephrine from induction to anaesthesia through caesarean section contributed to this result. Sympathetic activation caused venoconstriction, which significantly increased venous return and maintained haemodynamic stability.