When the newborn's crib was moved suddenly, the nurse noticed that his legs flexed and the arms fanned out, and then both came back toward the midline. The nurse would interpret this behavior as:

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.

Check for blood under the client's buttock. This is because lochia rubra is the normal vaginal discharge that occurs after childbirth, consisting of blood, mucus, and tissue from the placenta and the uterus lining. It is usually heavy for the first three to four days and can pool under the client's buttocks if they are lying down. Checking for blood under the buttock can help assess the amount of bleeding and prevent complications such as infection or hemorrhage.

The other choices are not correct for the following reasons:

A. Increasing the rate of the IV fluids is not necessary because the client's fundus is firm and midline, indicating that the uterus is contracting well and preventing excessive bleeding.

B. Assisting the client to ambulate is not advisable because it can increase the lochia flow and cause fainting or dizziness due to blood loss.

C. Performing fundal massage is not indicated because the fundus is already firm and midline, meaning that the uterus is adequately contracted. Massaging a firm fundus can cause pain and discomfort to the client.