Should you dye your hair when you're pregnant? What about a mani-pedi? To clear the air for moms-to-be who need a little beauty pampering, a health expert allays a few worries.

"Women face a lot of uncertainty as their bodies change during pregnancy, and many worry about how to look their best," said Mary Rosser, MD, PhD, Department of Obstetrics & Gynecology and Women's Health, Montefiore Medical Center, and professor at Albert Einstein College of Medicine of Yeshiva University in New York, in a statement.

"We work hard to separate truth from fiction to put mothers at ease and help them figure out ways to make this special time in their lives consistent with the way they're used to living and looking."

Is it safe to dye your hair during pregnancy?

Generally speaking, dyes are safe but try to be completely natural during pregnancy, she noted. If you must color your hair, do so after the first trimester and in a well-ventilated space; let your hair stylist know you are pregnant and ask to try not to allow chemicals to touch the scalp. "The real concern is breathing the ammonia fumes that could be harmful to the developing baby in the first three months of pregnancy," Rosser said. "Women should be mindful of the fumes in straightening products as well." To be even safer, try vegetable dyes such as henna.

Is it safe to get your nails done when pregnant?

Yes, but wait until the second trimester, when the risk to the developing fetus is lower. Also be sure the instruments are sterilized and ask the nail technician to not cut the cuticles to prevent exposure to bacteria and germs, Rosser advised. Skip the acrylic nails as well, since the adhesives contain harmful chemicals, which can be inhaled when the nails are filed.

What about skin care?

You can generally maintain your skin routine, but avoid products with Retin A or tetracycline, which can cause birth defects. "Stretch marks are not completely avoidable but you can try rubbing vitamin E oil on the areas most likely to be affected," she said.