Is it safe to scuba dive while pregnant?

In adults, the lungs filter small bubbles out of the blood after a dive. Before birth, most of the baby's blood bypasses the lungs, so DAN explains that this filtering doesn't happen in the fetus — which may raise the risk of bubbles reaching the arterial circulation, with potentially severe consequences.

DAN describes the data as limited and in many cases inconsistent: human studies are mostly surveys, which can show correlations but not cause, and much of the rest comes from animal studies. Ethical limits mean better studies are unlikely. With uncertain risk and an easy alternative — not diving — the guidance errs on the side of caution.

The UHMS/DAN physician guidance states that a pregnancy discovered after diving is not considered grounds for termination. Talk to your doctor or obstetrician about any concerns.

Relax on the boat with a diving partner or friends. Ask your doctor before any water activity during pregnancy.