Your baby is swallowing and recycling almost half a liter of amniotic fluid each day. In addition to providing him with nutrients, especially proteins, this fluid is important for the healthy development of the gut. Your baby's sense of taste is thought to have developed to such an extent now that if you have eaten spiced food he can distinguish this in the fluid he drinks.
Amniotic fluid does not enter the lungs but travels down the esophagus into the stomach where it is stored for a short time. At this stage, the stomach fills every 40 minutes, but, from 35 weeks, as the stomach enlarges, this rate slows down to every 80 minutes. Muscle contractions move the fluid in waves into the small and then large bowel. As it travels along the bowel, water is reabsorbed so that only waste material or "meconium," enters the colon, the final section of the large bowel. This meconium accumulates in the large bowel, which is completely full by the time your baby is born. Babies don't usually pass meconium before the birth but do so soon after. Meconium consists mainly of skin cells, lanugo hairs, and vernix. It has a greenish color due to the presence of bilirubin, a breakdown product from red blood cells.