Hold on to your Pampers! Ashlee Simpson and Pete Wentz are locked in a bitter baby battle.

The career-minded performer is putting off her Fall Out Boy husband’s dream for baby No. 2 because she thinks a new pregnancy will interfere with new TV show, say insiders.

"Pete wants Ashlee pregnant NOW," a family friend told The ENQUIRER.

"He wants a big family. And he’s adamant that the children should be close in age.

"But Ashlee is consumed with making it as a serious actress. Each time Pete brings up the idea of a new baby, Ashlee groans, ‘We just had one!’"

The two are thrilled with parenthood and Bronx Mowgli, their 8-month-old son, said the friend.

"While Ashlee does want more kids, she wants to wait a couple of years. It’s Pete who is getting antsy – and the baby issue is starting to create conflict."

Ashlee’s new show, Melrose Place, debuts on the CW this fall, and the 24-year-old singer-turned-actress is hoping it will establish her as a TV name.

"Ashlee worked hard to slim down and lose the baby weight after Bronx was born in November," said the friend. "She thinks another pregnancy now will slow her career momentum."

At 5-foot-6 and 110 pounds, the performer feels she’s ready for the cameras.

"And the last thing she wants is to jeopardize this new television gig because of morning sickness and dealing with the physical toll of a pregnancy," said the pal.