First of all, DON’T! Tattoo inks contain carcinogenic, mutagenic, and reproductive toxic substances of unknown significance.
Moreover, there is absolutely no pressing reason why someone needs to undergo an elective procedure while pregnant. Your body undergoes so many changes during pregnancy that getting a tattoo could be a cosmetic disaster with unintended consequences.
One of the most unusual cases that I can remember is a patient of mine who already had a tattoo on her lower abdomen, just above the bikini line.
It was a cute little fish that ended up growing into an enlarged, distorted whale with irregular borders and varying degrees of pigment that appear faded in areas.
The whole abdomen from the pubic bone to the rib cage grows substantially and stretches out the skin, and in many cases, stretch marks or striae appear as reddish-purplish raised squiggles with silvery depressed areas.
If a tattoo is placed on the abdomen, you have no way of knowing if you will develop a stretch mark in the same place—and it will be very difficult to remove postpartum because that skin is crepey and too stretchable.
So, maybe you want to get a tattoo in another area of the body. I would also advise caution because weight gain is fairly uniform and when you lose weight postpartum, the tattoo will shrink—and maybe completely unrecognizable.
Of course, it all depends on the timing of the tattoo. We also have no idea how the ink will react with the excess hormones circulating in the body.
Aside from the cosmetic uncertainty, there are real risks with skin allergies, sensitivity to sun exposure, which is already heightened in pregnancy due to elevated hormones.
Skin allergies can lead to itching, ulceration, scar build-up (keloid), sensitivity, and scarring.
Tattoo infections with bacteria, especially staphylococci, which may be resistant to multiple antibiotics, may be prominent and may progress into life-threatening blood infections that could be passed to the baby through the placenta.
Any type of infection in pregnancy can lead to preterm birth. Furthermore, your immune system is already suppressed in pregnancy, which makes any infection more likely.
Contaminated tattoo ink is a real risk, especially since ink supplies may come from unregulated countries, making contamination with Hepatitis B, C, and HIV a possibility.
Ink pigments may be picked up by the bloodstream and collect in lymph nodes, but reports are conflicting.
Inorganic pigments such as mercury and cadmium salts (poisons) are now being replaced by organic pigments. The tattoo ink products of today often have unknown ingredients and a range of chemical contaminants.