It is generally best to wait until after pregnancy to get a new tattoo. There is not enough research to confirm that tattooing during pregnancy is safe for the developing baby, so delaying an elective tattoo is the more cautious choice.
Tattooing breaks the skin and can lead to bacterial infections or, in unsafe settings, exposure to blood-borne infections such as hepatitis C. Serious infections after tattoos are uncommon, but they have been reported. Tattoo ink itself can also become contaminated, even when the tattoo artist follows good hygiene practices.
There is also uncertainty about the ingredients in tattoo inks. Research has shown that some tattoo pigments and metals can move from the skin to nearby lymph nodes, but it is not known whether these substances can reach the placenta or affect a developing baby.
If you already received a tattoo while pregnant, this does not mean that a problem will occur. Watch the area for increasing redness, swelling, pain, drainage, or other signs of infection, and contact your prenatal healthcare provider if you are concerned. Avoid getting additional tattoos during pregnancy and wait until afterward when possible.