Can probably slow the growth and development of the baby and can possibly increase the chance of the mother having a premature delivery.  Also they baby can go through withdrawal symptoms, cry and probably have a low immune system.

It blocks off food and water (liquid) from entering the trachea.  It also allows air to pass through the pharynx into the rest of the respiratory system. It basically prevent food and water from going into the lungs.

The common factor for 12 and 15 is 3. When you divide 3 into 12 the answer is 4 and 3 into 15 is 5.  The simplest form of 12/15 is 4/5.