GMC Sierra Denali 2006 Owner's Manual page 27

To unlatch the belt, just push the button on the buckle.
The belt should go back out of the way.
Before you close the door, be sure the belt is out of
the way. If you slam the door on it, you can damage
both the belt and your vehicle.
Safety Belt Use During Pregnancy
Safety belts work for everyone, including pregnant
women. Like all occupants, they are more likely to be
seriously injured if they do not wear safety belts.
A pregnant woman should wear a lap-shoulder belt,
and the lap portion should be worn as low as possible,
below the rounding, throughout the pregnancy.
The best way to protect the fetus is to protect the
mother. When a safety belt is worn properly, it is more
likely that the fetus will not be hurt in a crash. For
pregnant women, as for anyone, the key to making
safety belts effective is wearing them properly.
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