Berlin - Smoking a water-pipe carries the same health risks as cigarettes. With that in mind, the German Federal Institute for Risk Assessment, a statutory body under Germany's Ministry of Agriculture and Consumer Protection, has advised pregnant women and heart patients to avoid smoking hookahs.

The institute believes recent research shows that people who smoke hookahs inhale much higher levels of poisonous carbon monoxide than cigarette smokers.

Carbon monoxide bonds with haemoglobin in red blood cells, constricting oxygen transport in the body in the process. As carbon monoxide can also travel to the placenta, it can affect an unborn child, reducing the supply of oxygen.

The gas can also quickly lead to headaches and nausea. Water-pipes also have higher levels of other harmful substances than cigarettes.