Weight Gain in Pregnancy: What Happens in the 9th Month?

Question
I've heard that in the 9th month of pregnancy, weeks 37-40, many women either stop gaining weight or slow down significantly and that some even loose a few pounds.  Is this true?  If so, how common is it and why does it happen?

Thanks for your help!

Answer
Hello Laura- NO NO NO. The slight wt. loss happens in the last week or two and is only a little fluid shift getting ready to labor and birth. She should continue to eat only the highest quality of foods- no sugar or sweets and continue to gain to a total of 35 pounds for the pregnancy. Cheri.