Staying healthy during pregnancy is one of the best ways to protect your growing baby. Avoiding infections, preventing injury, and staying away from harmful chemicals are important steps you can take.
“Poison” is a scary word, but it’s scarier when you are pregnant. A poison is anything that can be harmful to your body: illegal drugs, pesticides, metals such as lead and mercury, gases such as carbon monoxide, and household cleaning products. Even things that are normally healthy (like over-the-counter and prescription drugs) can be poisonous if they are not used the right way or at the right doses. Poisoning can cause mild, short-term discomfort, but it can also cause brain damage, coma, and death.
Poisoning is a leading cause of hospitalization related to injury during pregnancy (only traffic accidents and falls are more frequent causes).  You should know how to protect yourself from poisoning while you are pregnant—and what to do about it if you come in contact with a potential poison. If you ever suspect that you have been exposed to poison, call your local poison control center at 1-800-222-1222.
One of the most common types of poisoning is food poisoning. This happens when something you eat contains bacteria, a virus, or any toxic substance that can harm your body. Most food poisoning is caused by norovirus, listeria, E. coli, and Salmonella.
During pregnancy, your metabolism and immune system change, which makes you more likely to get food poisoning. Additionally, your baby’s immune system is not fully functioning during pregnancy, so any infection—even from food—can be dangerous for them.
Usually, food poisoning causes vomiting, nausea, and diarrhea, but you may also experience headache, fever, abdominal pain, dehydration, and blood in your stool. Since you may already be experiencing these symptoms since you are pregnant, it may be hard to tell if they are normal or if they are caused by food poisoning. If the symptoms appear suddenly or are extreme or intense, call your doctor right away.
Of all the symptoms of food poisoning, dehydration (the loss of water) is a common cause of complications during pregnancy. You will know you are dehydrated if you are extremely thirsty, have dry lips, are producing little or no urine, or are dizzy. If you are throwing up or having diarrhea, you are losing a lot of water, so you must replenish what you’ve lost. Start by drinking small sips of water and then gradually increase how much you are drinking.
Malnutrition (not getting enough food or nutrients) is also possible from food poisoning, especially with a norovirus infection. E. coli can cause kidney damage and Salmonella may cause severe infections in your blood stream and brain or spinal cord, as well as arthritis. Listeria can cause long-term problems for your baby, such as paralysis, blindness, and seizures, and it can cause miscarriage, stillbirth, preterm labor and premature birth, and low birth weight.
Food safety is the best way to prevent food poisoning. Pay attention to how food is stored, the temperature to which food is cooked, and the expiration dates on food. Wash all fruits and vegetables thoroughly and avoid unpasteurized products while you are pregnant. For a list of foods to avoid during pregnancy, check out this article.
Carbon monoxide poisoning
Carbon monoxide is a gas that can be toxic to people. It is produced by fuel-burning appliances and it is especially dangerous if these appliances are used in enclosed spaces, such as using a charcoal grill indoors or running a car inside a closed garage. Smoke inhalation during a fire can also cause carbon monoxide poisoning.
Carbon monoxide is colorless, odorless, and tasteless so it is hard to know when you have been exposed to it. In your body, it enters your blood (and your baby’s) and replaces oxygen on hemoglobin molecules. Normally, hemoglobin helps deliver oxygen to all organs of the body, but when oxygen is replaced by carbon monoxide, the organs do not get the oxygen they need.
Symptoms of carbon monoxide poisoning include headache, nausea, vomiting, dizziness, fatigue, weakness, confusion, and disorientation. Since fetal blood cells take up carbon monoxide more easily than adult blood cells, the risk of long-term damage from carbon monoxide exposure is greater for unborn babies than for adults. Carbon monoxide poisoning can cause permanent brain damage, heart damage, fetal death or miscarriage, or maternal death.
Installing a carbon monoxide detector in your home is a simple measure that can prevent exposure to this potential poison. Alarms should be placed outside all sleeping areas. Further, all fuel-burning appliances, including furnaces, hot water heaters, stoves, fireplaces, and space heaters should be regularly inspected and maintained in good working condition.
Poisoning is a leading cause of hospitalization related to injury during pregnancy (only traffic accidents and falls are more frequent causes).
Chemicals called organophosphates are present in many pesticides. Exposure to these chemicals can occur by inhalation, ingestion, or through the skin. They can cause increased production of tears and saliva, diarrhea, nausea, vomiting, sweating, small pupils, muscle tremors, and confusion.  Exposure to organophosphates during pregnancy can cause spontaneous abortion, preterm birth, low birth weight, birth defects, developmental delays, and childhood brain cancers.  The most dangerous time for exposure is during the first few weeks of pregnancy.
There is no reliable treatment to reverse the effects of organophosphate poisoning, so it is important for pregnant women to avoid exposure to pesticides. Read all labels and warnings on household chemicals and take care to stay away from areas that you know have recently had pesticides applied. Long-term, intense exposures to pesticides offer the most substantial risk to mothers and babies, but it is best to avoid even small, short-term exposures, if possible. 
Click here to read more about avoiding pesticides during pregnancy.
If pregnant women are exposed to lead, it can result in high levels of lead in the blood of their babies. Women may be exposed to lead during home renovation projects, from herbal and botanical supplements, or by ingesting substances that may contain lead such as soil, clay, paint, or pottery. Lead stays in the body for decades, so even exposure before pregnancy can pose a risk for a woman’s unborn baby.
Lead exposure during pregnancy can damage many of the mother’s organs and organ systems, including blood, the liver, the kidneys, and the brain and spinal cord. Lead increases the risk of preeclampsia (high blood pressure) and may harm the unborn baby. Babies and children with high levels of lead may have behavioral and learning problems, lower intelligence, hearing problems, and impaired growth.
Avoid exposure to lead by staying away from lead-based paints and taking only dietary supplements approved by your doctor. If you have a condition that causes you to eat substances or products that are not food (called pica), talk to your doctor about your risk for lead exposure.
Staying healthy and avoiding exposure to anything that could harm you or your unborn baby is critical to a healthy pregnancy. If you have any questions about how to avoid exposure to poisons and toxins, talk to your doctor or pharmacist.
- Zelner I, Matlow J, Hutson JR, et al. Acute poisoning during pregnancy: observations from the Toxicology Investigators Consortium. J Med Toxicol. 2015;11(3):301-8.
- Robb EL, Baker MB. Organophsophate toxicity. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-.
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- Sun L, Li G-q, Yan P-b, et al. Clinical management of organophosphate poisoning in pregnancy. Am J Emerg Med. 2015;33(2):305.e1-3.