Scuba diving is a leisure activity increasingly popular amongst women. Many 
women are concerned about the risks associated with diving and a known or 
planned pregnancy. In order to advise these young women, we have reviewed the 
literature concerning women and diving as well as animal studies on the subject. 
The different international federations and the Undersea and Hyperbaric Medical 
Society advise against scuba diving for pregnant women or those planning a 
pregnancy, but no randomized trials or trials provide a solid scientific basis. 
The fetal circulation is characterized by the exclusion of the pulmonary 
circulation by 2 right to left shunts. As the lung appears to act as a filter 
against the progression of micro-bubbles to the main circulation, the fetus may 
be therefore particularly exposed to gas emboli. However, the placenta could 
play this role in certain animal species. Nitrox diving appears to be 
particularly promising, but studies on the subject are still insufficient to 
recommend it for pregnant women.