The best answer can be given to you by a primary health care provider, who will include in the first pregnancy consultation a list of specific foods which will aid in the development of the embryo into a fetus. Foods to be avoided are included as well.
Enotes.com can only provide you with general information. Each case of pregnancy is different, so please go by what the provider suggests, first and foremost.
Generally, pregnant women are particularly warned against indulging on raw foods such as sushi, sashimi, mussels, shrimp and other kinds of fish products.
The reasons are, a) the possible content of mercury in fish, b) the possibility of salmonella in undercooked fish products and, c) the chance of other bacteria accumulating in specific types of seafood. Shellfish is particularly discouraged precisely because it is not a type of seafood that you can cook with exactness. Also, the shell may carry bacteria from the primary location of the crustacean.
This being said, along with shellfish, any type of raw food is strongly advised against.
Caffeinated products are also discouraged because they change the heartbeat of the mother since caffeine is a stimulant. If the mother suffers from high blood pressure without knowing it, caffeine might increase it, adding to the risk factors of a stroke.
Particular attention is also paid to high sodium products for the same reason. High sodium contents in salty foods cause water retention and also increase blood pressure. Pregnancy already causes water retention. Pre-eclampsia is a super dangerous condition that may lead to death if the mother does not watch the level of water retention during her pregnancy. Therefore, watch very carefully for salty and pre-packaged foods.
Last but not least, high-sugar content should be averted due to the possibility of Prenatal diabetes. Many women suffer from a change in their insuline and blood sugar levels during pregnancy. As a result, they develop diabetes only for the duration of their pregnancy. However, the effects are long lasting, including excessive weight gain, water retention, and generalized malaise. This can be very dangerous as well.
In all, stick to healthy foods in the form of fruits, vegetables, and fresh meats. Wash your fruits and vegetables thoroughly before consumption to remove any trace of pesticides. Pre-packaged, canned, and frozen meals are high in preservatives, so do your best to make your own snacks and meals at home under your own supervision. Moreover, consult with your gynecologist and your primary health provider AT ALL TIMES prior to making any changes in your diet. Again, Enotes.com can only provide general information from secondary sources when it comes to medical help. Enjoy this life changing event as healthily as you possibly can!
Packaged ramen noodles, Soda, Shelf-stable commercial lunches, too many frozen prepared meals, Iceberg lettuce.