If you are thinking about becoming an expectant mother or are already pregnant, odds are good you’re studying up on the best diet to support your body and nourish your baby’s development. Here are two recent changes in nutritional guidelines that may help.

Pregnant women should eat at least 8 ounces to 12 ounces of low-mercury seafood each week, according to a 2014 recommendation. That amount is an increase from earlier guidelines that suggested consuming no more than 12 ounces of seafood per week.

Concerns about mercury have discouraged women from including fish in their diets. Food and Drug Administration studies found most U.S. pregnant women who included fish in their diet ate less than 4 ounces each week in the month before they were surveyed. The FDA said 21 percent of pregnant women did not eat any fish during the previous month.

Fish is a great source of protein and omega-3 fatty acid, which is important for a baby’s developing brain.

Nutrition experts say pregnant women should avoid large fish that can be high in mercury, such as mackerel and swordfish. They recommend small fish such as tilapia, salmon, cod, and shrimp. Limit canned tuna to less than 6 ounces per week for white albacore tuna or 12 ounces per week for chunk light tuna. Chunk light tuna contains less mercury than white albacore tuna.

Another dietary guideline change came in 2009 when the Institute of Medicine reduced its recommendation on the healthy amount of weight women should gain during pregnancy.

Institute guidelines suggest that underweight women gain between 28 lbs. and 40 lbs., normal weight women gain 25 lbs. to 35 lbs., overweight women gain between 15 lbs. to 25 lbs. and obese women gain 11 lbs. to 20 lbs.

One physician and chef says pregnant women only need an extra 300 calories a day, and she has written the new Natural Pregnancy Cookbook to offer healthy snacks and meals toward that goal. Dr. Sonali Ruder is creator of the food blog, The Foodie Physician.

“Eating for two doesn’t mean you should be eating twice as much. It means you should be eating twice as smart,” Ruder says.

Many women ask how much coffee they should drink during pregnancy. While the jury is still out, studies indicate that less than 200 mg of caffeine, or one small coffee, is safe each day, doctors say.

Another question that concerns many pregnant women is the nutritional value of vegetable smoothies and fruit juicing. Doctors tell pregnant women that they lose the fiber found in whole foods and may drink a lot of added sugar in these concoctions. They also recommend drinking 8 to 10 glasses of water daily.

Because folic acid is so important in a baby’s development very early in pregnancy, many doctors suggest taking a prenatal vitamin containing folic acid before becoming pregnant.

Find out more about pregnancy and diet in Pay Attention to Two Changes in Pregnancy Nutrition Guidelines.