Pregnancy comes with a roller-coaster ride of emotions - the excitement of bringing a new life into the world, the fear of whether the new child will be born healthy, and the frustration over swollen feet and favorite clothes that no longer fit. With nine months' worth of body changes and hormones raging, it's natural for pregnant women to seek some form of relaxation. The spa is a logical place to go to find some body-calming peace. However, pregnant women need to be careful about which treatments they receive. Consequences range from nausea in the mother to induction of labor of the baby.

Ann Douglas, a Canadian author of 27 pregnancy and parenting books, says the most important way to have a good experience at a spa with "a bun in the oven" is to let the spa workers know that you are pregnant. This way, they can ensure that you don't undergo treatments that could harm the baby.

Douglas also says that on the day of treatments, you should inform the technicians if you are experiencing morning sickness. The professional will be able to make accommodations, such as increasing ventilation in the room where you will be treated and using products with milder scents.

Throughout pregnancy, mothers-to-be are told to avoid extremely hot baths and showers. Because of this, you should pass on hot tubs, steam rooms and saunas, as well as thermal wraps and tanning beds, Douglas urged. (She added that tanning is also a bad idea because it can accentuate melasma - also known as chloasma or "the mask of pregnancy" - large areas of discoloration on the face that many pregnant women develop.) Though 10 minutes or less in a setting of 101° F should be OK, keep in mind that if your temperature rises above 102° F, your baby's brain development could be affected, author Karyn Repinski noted. Or, you could lose your baby to a miscarriage, noted Marjorie Greenfield, MD.

Another thing to avoid is lying on your back after the fifth month of pregnancy, Douglas said. Your abdomen is now resting on your major blood vessels and intestines, and the pressure can cause problems ranging from backache and breathing difficulties in the mother to a decrease in blood circulation to your baby, according to the American Pregnancy Association (APA).

With that said, here is the lowdown on some common types of spa treatments:

Massage: Massage is great for relaxing the tired muscles of expectant mothers, but during pregnancy, opt for a pregnancy massage, which uses lighter pressure than normal and avoids certain areas of the body. Seek out a professional trained in pregnancy or prenatal massage. Because it is not advised to lay on your back or your stomach (unless you are on a massage table with a hole in the center to accommodate a pregnant belly), your masseuse may have to modify your positioning. You may be placed on your side with pillows to prop you up, or you may have to sit in a massage chair, reported. Dr. Greenfield. She added that massage of the abdomen or breasts can cause contractions. (Some massage therapists also add the shoulders, shins and any area below the ankle to the list of labor-inducing massage areas, Repinski said.) You should also avoid deep massage to the legs because that could aggravate varicose veins (which commonly develop during pregnancy) or even cause injury or death by dislodging a blood clot, Douglas pointed out.

Aromatherapy: Dr. Greenfield indicated that essential oils of rose, eucalyptus, lemon, mandarin, frankincense and lavender have been tested for safety during pregnancy. However, you may want to avoid aromatherapy during that crucial first trimester (when your baby's vital organs begin to develop and body parts begin to differentiate), or even altogether if you have a history of miscarriages, Answers.com recommended.

Facial treatments: Most are fine, but keep in mind that pregnancy makes skin more sensitive, cautioned Repinski. Glycolic acid treatments may irritate the skin during pregnancy. Acne treatments, including Retin-A, Accutane and tetracycline come with risks to the development of the fetus. Over-the-counter salicylic acid treatments should also be avoided. It is best to talk with your doctor about acne treatment before scheduling any such treatments, the APA said.

Hair Treatments: Electrolysis is probably best avoided during pregnancy. Researchers aren't sure of how electrical current affects a growing baby, Repinski wrote, so many experts advise foregoing hair removal until after your baby is born. Others only restrict the procedure during the first trimester. Consult with your doctor before making a hair removal appointment with electrolysis.

Additionally, experts are equally positioned for and against hair coloring, perming and relaxing, noted Dr. Greenfield. Chemicals used in these procedures are absorbed through the skin into the bloodstream (meaning they could pass to the baby); but, as she noted, countless women have had these hair procedures over the years, and obvious problems in their babies have not been apparent. The decision on this one is up to you, but she said waiting until after the first trimester is a good rule of thumb (though some hair stylists say hair is more likely to break off with relaxer used later in the pregnancy). One hair treatment that shouldn't come with any side effects, however, is highlighting, because highlights do not touch your scalp, Dr. Greenfield said.