As important as watching what you eat and do during pregnancy is to be careful not to eat or come in contact with certain foods or substances that are not advisable in these months. In the first weeks and months of gestation the baby is developing its basic structure, and there are substances that are considered dangerous because they can alter this development.

Substances you must always avoid

• Alcohol: Alcohol crosses the placenta and can cause fetal alcohol syndrome. This syndrome could cause malformations and even mental retardation. The latest studies prove that even the smallest amounts of alcohol can have very adverse effects on your baby’s development.  

• Tobacco when you inhale tobacco smoke, the blood vessels in the placenta contract. The direct consequence is that the baby gets less oxygen and fewer nutrients. Babies of smoking mothers are usually born prematurely and weigh less. Even smoking only six cigarettes a day may cause the baby to have nicotine withdrawal symptoms.

• Drugs: as with alcohol or tobacco, there isn’t any drug considered safe during pregnancy. Cocaine, heroine or marihuana may cause malformations and mental retardation in the developing baby.

• Lead: lead is a metal that accumulates in the mother’s bones and tissues. This metal can affect the mental development of the baby. Lead is found in the paint of old buildings. Houses built on or before the year 1950 usually have lead on the walls. The water pipes of old houses have this risk. For this reason it’s advisable to have tap water run for 30 seconds before using it. Likewise you must be careful in using traditional home remedies which may contain high levels of lead, and with tin cans containing lead that are still sold in other countries and the wrappers of imported sweets and cosmetics from the Middle East (kajal, khol, and surna).

• Mercury: Just like lead it is a heavy metal. Mercury is what some thermometers contain: the silvery dense liquid. Some cosmetics bought in other countries may contain this metal and you should check their composition and not use them if in doubt. But especially you must avoid eating fish such as shark, swordfish and mackerel. The American Food and Drug Administration recommend that pregnant women don’t eat these fish because they usually accumulate mercury in their organism.

• Dyes: in general it’s best to wait at least until the end of the first trimester to dye your hair. Nevertheless, if you work in a hair salon over 40 hours a week with dyes or doing synthetic nails, try to have your workplace as well-ventilated as possible to avoid inhaling these compounds.

• Cleaning products: the ones that you should avoid during pregnancy are those products that give out fumes. If you must work with them, keep the area well ventilated and use gloves.

• Photographic and printing chemicals: there are certain products used in these industries that you should not manipulate during pregnancy, as for example arsenic, cadmium, and lithium, lead, toluene or vinyl chloride. If you work in any of these industries you must find out which chemicals you handle and tell your doctor.

Foods you must be careful with during pregnancy

Some foods may contain bacteria, viruses or toxic substances that could be harmful during pregnancy. Although they might not hurt you directly, they can affect the development of the fetus.

• Raw foods: there are raw foods that may have bacteria and parasites that are harmful to the baby. You must be especially careful with raw fish and seafood like sushi and ceviche, and raw meats like carpaccio, serrano ham, chorizo or other cured meats. In general, eat meats and fish that are cooked thoroughly and wash fruits and vegetables very well before eating them.

• Fish and meat: there are certain fish and meats that you should avoid during pregnancy because of the substances they might contain. The FDA warns pregnant women against consuming fish like: shark, swordfish, mackerel and sardines since they might contain mercury. Canned tuna is not recommended either during pregnancy. Fish is an excellent food but now that you are pregnant you should limit its consumption to six ounces twice a week. You should also avoid eating liver. Liver is the organ that filters the blood and may contain hormones, antibiotics and other drugs that are given to animals during breeding.

• Sweeteners and preservatives: cyclamate and saccharine shouldn’t be used during pregnancy. If you want to use artificial sweeteners don't have more than four packs per day of sucrose (Splenda) or aspartame (Equal or NutraSweet). As for preservatives, check the labels of the products you buy. If there is a long list of complicated words it's better to choose a more natural product just in case.

• Coffee and herbs: You should drink caffeinated coffee in moderation; only one or two cups a day because caffeine in excess is not good for the baby. (Be careful with other drinks that also contain caffeine like guarana, caffeinated colas or mate). In regard to herbs, there are many that are not advisable during pregnancy not even as an herbal tea or as home remedy. For the time being it's better to limit yourself to chamomile or mint tea if you want to drink an herbal tea.

Other precautions

Lastly, avoid taking any prescription or over the counter medicine without asking your doctor first, and very important: if you have a cat, or any other domestic animal, let your partner do the cleaning and changing of the litter box. Toxoplasmosis is a disease that can affect your baby during pregnancy and cats carry it.