This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Medical, surgical and gynaecological illness complicating pregnancy, Subject name: Gynaecology & Obstetrics
All of the following are predictive tests for PIH except 
Select and explain. 
A. Rolling over test, B. Serum uricacid, C. Gain in weight > 2 kg in one month, D. Shake test
D: Shake test
Answer: D: Shake test 
Explanation: Shake test or bubble test This is a useful bed side test rapidly performed with a fair degreeof accuracy.The test is based on the ability of pulmonary surfactant to form a foamor bubble on shaking which remains stable for atleast 15 mts.Increasing dilutions of amniotic fluid are mixed with 96%ethanol ,shaken for 15 s and inspected after 15 mts for the presenceof a complete ring of bubbles at the meniscus.If it is present the test is possitive and indicate maturity of fetal lungs D.C.DUTTA&;S TEXTBOOK OF OBSTETRICS,Pg no:111,7th edition