HESI Focus on Maternity Exam

Correct Answer: A

Rationale: The correct answer is A: 'A Rh-negative mother who has an Rh-positive infant.' In cases where the newborn is born post-term, the mismatched Rh factor between the mother (Rh-negative) and the infant (Rh-positive) can lead to hemolytic disease of the newborn. This condition occurs when maternal antibodies attack fetal red blood cells, causing hemolysis. This can result in jaundice, anemia, and other serious complications for the infant. Choices B, C, and D are incorrect because they do not reflect the mismatched Rh factor scenario that poses a risk for hemolytic disease of the newborn.

Correct Answer: C

Rationale: Sickle cell anemia is most commonly found in individuals of African American descent. This is because sickle cell trait provides some protection against malaria, and historically, regions where malaria is or was prevalent have higher rates of sickle cell anemia. Therefore, individuals with African ancestry are at a higher risk of developing sickle cell anemia compared to other populations. Choices A, B, and D are less likely to develop sickle cell anemia due to lower genetic prevalence in their respective populations.

Correct Answer: D

Rationale: The correct answer is D because phytonadione (vitamin K) is administered to newborns to prevent hemorrhagic disease due to their low levels of vitamin K, which is essential for blood clotting. Choice A is incorrect as vitamin K administration is not related to improving dietary intake. Choice B is incorrect as vitamin K doesn't stimulate the immune system. Choice C is incorrect as vitamin K is not given to help an immature liver, but rather to prevent hemorrhagic disorders.

Correct Answer: A

Rationale: At 14 weeks of gestation, the uterus is still relatively low in the abdomen. Placing the Doppler midline 2 to 3 cm above the symphysis pubis is appropriate for assessing the fetal heart rate. This location allows for better detection of the fetal heart tones as the uterus is at a lower position during this stage of pregnancy. Placing the Doppler on the left upper abdomen would not be ideal at 14 weeks gestation as the uterus is not yet at that level. Placing it two fingerbreadths above the umbilicus or lateral at the xiphoid process would also not be accurate for locating the fetal heart rate at this stage of gestation.

Correct Answer: B

Rationale: Betamethasone is a corticosteroid given to stimulate fetal lung maturity and reduce the risk of respiratory distress syndrome in preterm infants. Ampicillin (Choice A) is an antibiotic and does not prevent respiratory distress syndrome. Terbutaline (Choice C) is a tocolytic used to inhibit contractions and does not directly prevent respiratory distress syndrome. Butorphanol tartrate (Choice D) is an opioid analgesic and does not have a role in preventing respiratory distress syndrome in preterm infants.