Scuba diving is a no-no during pregnancy, but if you're lucky enough to take a tropical vacation while you're expecting, snorkeling might be an option. Check with your doctor first before you grab your swimsuit and head out to the reef, and consider the following precautions. You might even discover that fish-watching is pregnancy stress-buster.

Considerations

First consider your fitness level and the conditions where you'll snorkel. Snorkeling is not usually considered vigorous exercise, especially if you're wearing fins, snorkeling in areas without a current or wearing an inflatable vest. In fact, a Brazilian study published in the journal "Reproductive Health" in 2009 tested the safety of water aerobics on pregnant women. The report concluded that, even among women not accustomed to exercise, water aerobics are safe during pregnancy.

Oxygen, Please

As tempting as it may be to dive down and snag a sea shell on the ocean's sandy bottom, resist the urge. Because your baby requires a constant supply of oxygen, it's never a good idea to hold your breath while you're pregnant. For the same reason, it's important to make sure you're comfortable breathing through a snorkel before paddling out to the reef. If you're not comfortable, you may be inclined to hold your breath or breath in rapid gasps. To reduce the need for oxygen, use fins and, if needed, a vest. The evidence behind not holding your breath is so compelling that KidsHealth.org recommends not even holding your breath during any pregnancy exercise.

Body Temperature

Since snorkeling usually includes sunny days, warm waters and tropical locations, you're likely to be snorkeling during hot weather. Be especially careful to not overhead, especially in your first trimester, because birth defects can occur in fetuses of women with prolonged elevated temperatures. Avoid snorkeling midday, and remember that you may underestimate your body temperature while swimming. Cool water will cool your skin and make you feel cooler than your actual body temperature. Take breaks to sip fluids since water helps regulate your body temperature.

Additional Concerns

Take extra care to avoid injuring yourself while snorkeling -- after all, you may be thousands of miles away from your regular doctor. Pay extra attention to the typical warnings given to snorkelers. Avoid placing your feet down near the sharp spines of sea urchins, often which are hidden among rock and coral. Keep an eye out for jellyfish and other dangerous creatures, depending on your location. If you're not snorkeling in a protected area, use a dive flag since boaters will have a difficult time seeing you while you're lying flat amongst the waves. And, of course, enjoy. The next time you snorkel, you may be showing off a reef to your new child.