For many, cold and flu season consists of stocking up on NyQuil and Sudafed in hopes of battling symptoms at the first sign of sickness. But those who are pregnant or nursing may want to think twice about taking many common medicines.

"The No. 1 tip we give all of our patients is rest and fluids," said Dr. John McCarter, an obstetrician at Utah Valley Regional Medical Center. "You can take those over-the-counter medications, but there is always risk."

He says some medications, like Tylenol, are safe for pregnant women to take. Robitussin is an effective way to treat a cold without the possible harmful side effects to an unborn baby. McCarter also says Sudafed can be used but only after the first trimester.

"Sudafed taken during the first trimester has been linked to birth defects," McCarter said. "There are risks of intestinal defects. The first trimester is when the baby forms, so most of those medications are OK during the second and third trimesters."

McCarter says while some medicines have been linked to birth defects most over-the-counter cold medicines, including NyQuil, have never been tested for safety during pregnancy.

"The problem with all medications is nobody is going to do a study and give these potentially harmful medicines to a pregnant woman and see what happens," he said.

Pregnant women aren't the only ones who need to be careful; those who are trying to get pregnant and women who are breast feeding also need to be careful. McCarter says the biggest side effects of cold medications in babies who breast feed is drowsiness, but high doses can be toxic.

"I tell any patient that is trying to get pregnant to consider yourself pregnant," McCarter said. "That goes with medications too. Act as if you are pregnant because for the first six to eight weeks you may not even know you are and that can be the most important time in the baby's formation."

McCarter recommends all pregnant women as well as those with babies get a flu shot to protect themselves, make sure to wash their hands often and stay away from sick people. He says if you do get sick make sure you contact your doctor before taking any medications.

"Cold medications have never been proven to decrease the duration of a cold," he said. "The best thing anyone can do is get plenty of rest and fluids."

The pregnancy risk line, run by the Utah Department of Health and the University of Utah Health Sciences Center, has released five things pregnant women should watch out for if they are going to take a cold medicine. They say less is better, make sure you are only taking medications that match your symptoms, consider nasal sprays or drops if you have high blood pressure and pay attention to herbal ingredients as they can be harmful as well. They also say pay attention to medications with extra vitamin C, like throat lozenges, because it is possible to get too much vitamin C. Also, look for alcohol-free alternatives to traditional cough medicines.

If you have questions about which medications may or may not be safe you can contact the pregnancy risk line at 800-822-2229 or call your doctor.