Following delivery, the nurse's assessment reveals a soft, boggy uterus located above the level of the umbilicus. The appropriate intervention is:

The foramen ovale closes, preventing blood exchange from right to left in the heart. This is because the foramen ovale is a fetal shunt that allows blood to bypass the lungs and flow from the right atrium to the left atrium. After birth, when the baby starts to breathe air, the lungs expand and the pulmonary resistance decreases. This causes an increase in blood flow and pressure in the left atrium, which pushes the foramen ovale closed. This prevents blood from mixing between the right and left sides of the heart and allows oxygenated blood to circulate to the body¹².

Choice A is not correct because the ductus arteriosus does not expand to allow more blood to enter the lungs. The ductus arteriosus is another fetal shunt that

connects the pulmonary artery to the aorta. It allows blood to bypass the lungs and flow from the right ventricle to the aorta. After birth, when the baby starts to breathe air, the oxygen concentration in the blood increases and causes the ductus arteriosus to constrict and close. This increases blood flow to the lungs and decreases blood flow to the aorta.

Choice C is not correct because the umbilical vein that carried oxygenated blood in utero does not become the ascending aorta entering the right atrium. The umbilical vein is a fetal vessel that carries oxygenated blood from the placenta to the fetus. It connects to either the portal vein or the ductus venosus, which then drains into the inferior vena cava. After birth, when the umbilical cord is clamped and cut, the umbilical vein collapses and becomes a fibrous cord called ligamentum teres hepatis.

Choice D is not correct because the ductus venosus does not shunt oxygenated aortic blood to the lungs. The ductus venosus is another fetal vessel that connects the umbilical vein to the inferior vena cava. It allows some of the oxygenated blood from the placenta to bypass the liver and enter directly into the systemic circulation. After birth, when the umbilical cord is clamped and cut, the ductus venosus closes and becomes a fibrous cord called ligamentum venosum.

The Moro reflex was elicited. This is because the Moro reflex is a normal newborn reflex that occurs when the baby is startled by a loud noise or a sudden movement. The baby responds by extending the arms and legs, opening the hands, and then bringing the arms and legs back to the chest.

The Moro reflex is present at birth and disappears by 3 to 6 months of age.

Choice B is wrong because this is not abnormal for a full-term infant. The Moro reflex is a sign of a healthy nervous system and brain development.

Choice C is wrong because there is no evidence of an abnormality in the musculoskeletal system. The Moro reflex does not indicate any problems with the bones or muscles of the baby.

Choice D is wrong because the full-term infant should react to sudden movement. The Moro reflex is a protective response that helps the baby cling to the mother in case of danger.