Because birth has always been linked to death, there are many rites that aim to protect the life of the child and aid its passage into the world.
The neck of the uterus has to open for the baby to come out, so opening forms a large part of many rituals. In order to help the dilation of the neck of the uterus, women who are giving birth undo knots, ties and open anything that can be closed. In Morocco, for example, pregnant women have to leave their heads uncovered, their hair down and their belts undone. In India, mums-to-be also wear their hair down and remove any bracelets, rings and jewelry. They also leave all of the doors in their house open.
Warding off evil spirits
There is a popular belief that when you give birth you're at risk of being infiltrated by evil forces, so mother and baby have to be protected. In some countries, its traditional to close everything rather than open it! In Mexico, doors and windows are closed and the slightest chink or hole is blocked up with cloths. Some centuries ago in Europe, everything had to be closed and the house had to be overheated to chase away evil spirits and to protect the mother from the cold. This is still practice in some Asian countries, where a fire must burn permenantly for a month after a baby's birth.