Pregnant star Ashlee Simpson has hit out at reports she is desperate to lose her baby weight, insisting her main concern is the health of her child.

U.S. tabloid The National Enquirer reported earlier this week the singer had broken down into tears after learning she had gained more weight than is considered healthy.

The publication even alleged Simpson had bought several pairs of size zero jeans from Los Angeles shop Planet Blue to give herself an incentive to shed her post-pregnancy pounds.

But, posting on her official MySpace blog on Friday, the mom-to-be writes: "1. My doctor says I am right on target with my weight gain. 2. Have not been to Planet Blue in at least two years. 3. Love my maternity jeans ... they have stretchy tops - it is awesome!"

She adds: "Carrying a child is the most inspiring, emotional, amazing experience of my life. My weight and my pant size are the absolute last thing I am concerned about."

"I am only concerned with having a healthy pregnancy and a healthy baby. People who talk and judge pregnant women's weight need to get a life!!!"

Simpson and Fall Out Boy star Pete Wentz are said to be expecting their first child in October.