Regardless of whether you are pregnant or not, exposure to the sun puts you at risk for premature aging and malignant melanoma (skin cancer). Drink plenty of water, use a sunscreen with SPF 30 or more, and wear a hat. Pregnancy makes your skin more sensitive so the sun may cause hives, heat rash or worsened chloasma. I wouldn't stay in the sun for long periods. As far as laying on your stomach, it should be ok as long as you're comfortable.
at 8:14 AM on Jun. 12, 2009