A pregnant woman in 3rd trimester has normal blood pressure when standing and sitting. When supine, BP drops to 90/50. What is the diagnosis?

Ans. is c, i.e. Compression of IVC (inferior vena cava)Ref. Dutta Obs. 7/e, p 53, 54Supine hypotension syndrome:During late pregnancy Q the gravid uterus produces a compression effect on the inferior vena cava, when the patient is the supine position.This, generally results in opening up of collateral circulation by means of paravertebral and azygous veins.In some cases (10%) when the collateral circulation fails to open, the venous return of the heart may be seriously curtailed which results in production of hypotension, tachycardia and syncope. Normal blood pressure is quickly restored by turning the patient to lateral position.