At MotherToBaby we receive all kinds of questions about exposures during pregnancy. Most often, we teratogen information specialists get similar questions no matter what state or part of the country we work in. Commonly asked questions cover topics like medications, supplements, and alcohol. We also get questions about less common exposures too, such as someone taking their pet’s medication or a chemical spill in the workplace. Working in Arizona, we sometimes get questions that specialists in other parts of the country do not get- such as what happens if a woman is bitten by a rattlesnake during pregnancy.
Get Medical Care Right Away
Anyone who is bitten by a rattlesnake should seek medical care immediately—even if they do not notice symptoms at first. This is especially important during pregnancy.
Symptoms can include:
- Pain and swelling at the bite site
- Nausea
- Swelling of the mouth or throat
- Trouble breathing
- Bleeding or blood clotting problems
People should not try to treat a snake bite themselves. Quick and appropriate medical care can lower the risk of serious complications.
Complications
Blood clots are one serious complication that is possible from a rattlesnake bite. Although anyone can develop a blood clot, pregnancy increases the risk by about five times. Clots can reduce blood flow to the fetus or travel to the lungs (pulmonary embolism), which can be life-threatening. Complications related to blood clots include miscarriage, stillbirth, reduced fetal growth, thrombosis (clots blocking veins or arteries), placental insufficiency (reduced oxygen and nutrients reaching the fetus), changes in blood pressure, preterm delivery (before week 37), heart attack, stroke, and death.
It is important to remember that birth defects and miscarriage can happen in any pregnancy for many reasons. About 3 out of 100 babies (3%) are born with a birth defect each year, and miscarriage is common. Information on snake bites during pregnancy is limited. Case reports describe hydrocephalus (fluid buildup in the brain), intracranial hemorrhage (bleeding in the skull), reduced fetal movement, placental abruption, miscarriage, stillbirth, and maternal death. While case reports cannot prove that venom caused these outcomes, they show that snake bites can be serious and require prompt treatment. Outcomes may depend on the amount of venom, the stage of pregnancy, how quickly treatment begins, and the type and quality of care received.
Treatment During Pregnancy
Treatment for rattlesnake bites may include:
- Antivenom (medicine made of antibodies that helps neutralize venom)
- Blood tests to monitor clotting
- Monitoring fetal movement and/or fetal heart rate
There are reports of healthy babies being born after treatment with antivenom. Although information is limited, experts believe that treating a rattlesnake bite with antivenom is safer than leaving the bite untreated during pregnancy. In the small number of babies followed after exposure to antivenom during pregnancy, no long-term health problems have been reported.
Final Thoughts
A rattlesnake bite during pregnancy is a medical emergency. Immediate treatment and careful monitoring are likely to be recommended to protect both the mother and fetus. While there are still gaps in what we know, prompt medical care offers the best chance for a healthy outcome.
More information on rattlesnake bites can be found at the Arizona Poison and Drug Information Center website here.
Originally published 12/20/22. Updated 2/17/26.
