Vomiting on the first day of birth is caused by

Infant may vomit mucus, occasionally blood streaked in the first few hour after birth, if may be due to irritation of the gastric mucosa by material swallowed during delivery. • A large number of normal babies vomit on first day due to irritation of stomach by swallowed amniotic fluid • Vomiting from esophageal obstruction occurs with the first feeding • Vomiting due to obstruction of the small intestine usually begins on the 1st day of life and is frequent persistent, usual, non projectile, copious, and unless the obstruction is above the ampulla of vater, bile- stained. • Vomiting of pyloric stenosis may begin any time after birth but does not assume its characteristic pattern before the 2nd, 3rd week