A first-time mother reports that she is experiencing difficulty breastfeeding her newborn. The neonatal reflex that the nurse would teach the mother to elicit, in order to facilitate breastfeeding 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.

Pathologic jaundice. This type of jaundice occurs within the first 24 hours of birth and is caused by an underlying health condition, such as blood type incompatibility, infection, or liver problems. It can lead to serious complications, such as brain damage, if not treated promptly. Pathologic jaundice requires medical attention and often involves phototherapy or blood transfusion to lower the bilirubin levels in the baby's blood.

Choice A is not correct because physiologic jaundice is a normal and harmless condition that affects most newborns. It usually appears between the second and fourth day after birth and resolves by the second week. It is caused by the immature liver's inability to process bilirubin efficiently.

Choice C is not correct because breast milk jaundice is a rare condition that affects some breastfed babies. It usually appears after the first week of life and lasts up to a month or longer. It is caused by a substance in breast milk that interferes with the liver's ability to eliminate bilirubin.