**2. Anatomic changes in pregnant women**

The main changes occur by the consequences of growing uterus. The diaphragm is placed upwards. Hence, a shortening of the ribcage and an increase in the anteroposterior and right–left planes take place. Expansion from the ligamentous attachment areas of the ribs facilitates adaptation to these anatomical changes. With the effect of the increasing weight in the pregnant, the obscurity of the anatomical signs on the face and the enlargement of the breasts are among the reasons that cause the difficulty of tracheal intubation. As the uterus continues growing during pregnancy, the intraabdominal part of the stomach and esophagus are displaced to the left of the diaphragm. With this physiological change, progesterone and estrogen cause a decrease in esophageal lower sphincter pressure.
