Dear Doctor. My sister is pregnant and carrying 7th month. She has been suffering from breathing problem since 5th month. Only she feels relief when inhale huge amount of air. She is not able not to breath normally and she can't stand for long time. Actually she is carrying second baby. She didn't feel these kind of difficulties on her first 1st baby. What are the causes for these difficulties doctor and how to get rid of it. Pls help her.