Like many celebrities, Gwen Stefani had breast implants. The plastic surgery increased her breast size from an A cup to a 32B. She's taken fairly conservative approaches to all of the plastic surgery she's had in the past. Although it's pretty obvious she had a boob job, it's not over the top. Pretty much any boob job is obvious, but it's all about finding the right size that fits your body type. Gwen Stefani achieved that with her breast implants.