Meconium Colored Water
This is when the baby has had a bowel movement inside the uterus. This can become a problem if it is very thick. The baby can aspirate some of the stool into its lungs before or at the birth. Sometimes the baby will be suctioned well prior to the delivery of the body, as you pant to prevent pushing the baby out too fast, and also suctioned well after the birth. The latest studies show that although we may suction a baby well, that may actually not prevent meconium aspiration. Sometimes this suctioning can cause more harm. Your care provider will decide at the birth what is the best thing to do. Remember that the baby may have already aspirated prior to the birth, so this does not mean that the baby may not have problems.
Can you avoid this from happening to the baby? There is some belief that if you try to avoid stress in your life, it will reduce stress to the baby and thus less of a chance for this to happen. Is there scientific research to back this? No. None that I know of. But it would not hurt to avoid stress.
Also, overdue babies may be more likely to have a bowel movement prior to the birth.