Are pet rodents safe during pregnancy?

What does the evidence say about pet rodents during pregnancy?

1. Wild rodents, pet rodents, and laboratory rodents can all carry LCMV, and pet hamsters and guinea pigs can become infected if they're exposed to wild mice. 1
2. House mice are the primary reservoir for LCMV, with an estimated 5 to 10 percent carrying the virus in the US, and human infection happens through contact with infected rodent body fluids or feces via the mouth, broken skin, eyes, or nose, or through a bite. 2
3. Maternal LCMV infection raises the risk of miscarriage, with the risk notably higher when infection occurs in the first trimester, while congenital LCMV in later pregnancy is linked to serious complications including hydrocephalus, microcephaly, and vision loss, plus a higher risk of preterm delivery and low birth weight. 2
4. A case report described a pregnant farm and market worker who was bitten by a wild mouse at six weeks of pregnancy and developed fever, muscle pain, and photophobia days later; fetal ultrasound at 22 weeks found severe ventriculomegaly, and LCMV infection was confirmed by antibodies in fetal blood and spinal fluid, illustrating how a single wild-rodent exposure early in pregnancy can lead to severe congenital infection. 3
5. A review of two congenital LCMV cases found both infants had significant brain findings, including ventriculomegaly requiring a shunt and eye abnormalities affecting vision, with global developmental delay still present at 12 months of follow-up, underscoring why avoiding new exposure and delegating rodent care matters throughout pregnancy, not just around a known illness. 4

Is pet rodents safe in each trimester?

• First trimester. Miscarriage risk from LCMV infection appears higher when infection happens during the first trimester, which makes this the trimester to be most careful about delegating rodent care if possible.
• Second trimester. Birth defects linked to congenital LCMV, including fluid on the brain and small head size, appear more likely with infections in the second and third trimesters, so the same precautions matter throughout, not just early on.
• Third trimester. Same guidance continues. If you must handle cage cleaning yourself, avoid stirring up dust or debris, since the virus can become airborne from dried droppings or bedding.