Correct Answer: C

Rationale: Uterine atony is the most likely cause of bleeding 4 hours after delivery, especially after delivering a macrosomic infant and augmenting labor with oxytocin. Uterine atony is characterized by the inability of the uterine muscles to contract effectively after childbirth, leading to excessive bleeding. The other options, such as retained placental fragments (A), unrepaired vaginal lacerations (B), and puerperal infection (D), are less likely causes of postpartum hemorrhage in this scenario. Retained placental fragments can cause bleeding, but this typically presents earlier than 4 hours postpartum. Unrepaired vaginal lacerations would likely be evident sooner and not typically result in significant bleeding. Puerperal infection is not a common cause of immediate postpartum hemorrhage unless there are other signs of infection present.

Correct Answer: C

Rationale: Tim's physical characteristics, such as narrow shoulders, low muscle mass, and lack of facial and body hair, are typical signs of Klinefelter syndrome, a genetic condition where males have an extra X chromosome (XXY). This leads to underdeveloped testes and reduced testosterone production, resulting in features like gynecomastia, sparse facial and body hair, and reduced muscle mass. Testosterone replacement therapy is commonly used to address the hormonal imbalance in individuals with Klinefelter syndrome. Phenylketonuria (PKU) is a metabolic disorder unrelated to the symptoms described in Tim's case. Cystic fibrosis is a genetic respiratory condition that does not present with the physical characteristics mentioned. Huntington's disease (HD) is a neurodegenerative disorder primarily affecting motor function and cognition, not physical appearance and muscle mass.

Correct Answer: B

Rationale: Administering an epidural too early in labor, especially at 2 cm dilation, can slow down the progress of labor. It is usually recommended to wait until labor is more established. Choice A is incorrect because catheterization is not a prerequisite for epidural administration. Choice C is incorrect as waiting until 8 cm dilation is not a standard requirement for epidural administration. Choice D is incorrect because the baby's station being at zero is not a strict criterion for epidural administration.

Correct Answer: B

Rationale: An elevated AFP level during pregnancy can indicate potential fetal anomalies. Further evaluation is necessary to confirm the findings and assess the need for additional interventions. Scheduling a sonogram is the appropriate next step as it can provide more definitive results and help identify any underlying issues. Choice A is incorrect because dismissing the elevated AFP level as a false reading without further investigation can lead to missing important information about the baby's health. Choice C is not the best immediate action, as scheduling a sonogram would provide more detailed information than just repeating the AFP test. Choice D is incorrect as discussing intrauterine surgical correction is premature at this stage and not typically indicated based solely on an elevated AFP level.

Correct Answer: C

Rationale: The correct answer is C. Sickle-cell anemia results from a mutation in the beta-globin gene, causing red blood cells to become sickle-shaped. These misshapen cells can obstruct small blood vessels, leading to reduced oxygen delivery to tissues. Choices A, B, and D are incorrect because sickle-cell anemia is typically managed with treatments such as pain relief medications, hydration, and in severe cases, blood transfusions. It is caused by a specific mutation in the beta-globin gene, not by the inability to metabolize phenylalanine. Additionally, sickle-cell anemia is more prevalent in individuals of African, Mediterranean, Middle Eastern, and Indian descent, not exclusive to any specific gender.