One of the main staples of any babymoon is a good a spa.
Karisma's fantastic collection of resorts along the Riviera Maya includes several fine spas . I recently experienced the El Dorado Casitas Spa first hand where I had a sugar scrub treatment that is just perfect for expecting Moms. The combination of a nice light massage and the (almost) total body exfoliation treatment literally gives new life to your skin.
Let us know if you'd like to do your own site inspection. Give it a try!