What is it about a baby bump that makes celebrities want to shed their apparel like they're on spring break?

While most expectant mothers slip into some comfy maternity sweats and wait out the nine months until it’s time to show skin again, as ever, stars do things differently. They get naked. Super naked. Like, Playboy naked. They roll around on the floor in nothing but heels with a level of shamelessness even Rihanna would wag a finger at, claiming they've never felt sexier.

Now, don’t get us wrong ― pregnancy is a beautiful, natural state, and all women should love their bodies at every stage in the process. But do we need see every inch of them?

As Sienna Miller joins the ranks of women of who have dared to bare it all while expecting, here’s our round-up of birthday suit bumps ranked from most tasteful to tackiest.