RNC-OB exam prep: 3,749 inpatient obstetric questions with rationales

A is correct.Active management of the third stage of labor is a bundle designed to shorten placental delivery and reduce postpartum hemorrhage. It combines prophylactic oxytocin, given with birth of the anterior shoulder or soon after the newborn is born, controlled cord traction with countertraction above the symphysis to support the uterus, and uterine massage with fundal tone checks after the placenta delivers. Oxytocin is the most effective single component, so it should not be omitted even when other steps are modified. Awaiting separation signs, maternal pushing, and early breastfeeding describes expectant or physiologic management, in which the placenta separates and delivers on its own; it is associated with greater blood loss and is not active management. Routine fundal pressure, immediate cord clamping, and methylergonovine is incorrect because pushing on a relaxed fundus can cause uterine inversion, immediate clamping is no longer advised because delayed clamping benefits the newborn and does not interfere with active management, and methylergonovine is reserved for treating atony and is avoided with hypertension. The nurse prepares oxytocin, supports controlled traction, and monitors fundal tone and bleeding.

C is correct.Under the NICHD definitions used in current practice, a variable deceleration is a visually apparent abrupt decrease in fetal heart rate, meaning the time from onset to nadir is less than 30 seconds. The drop is at least 15 beats per minute below baseline and lasts at least 15 seconds but less than 2 minutes, and its timing, depth, and shape may vary from one contraction to the next. Variables are caused by umbilical cord compression. A nadir occurring after the peak of the contraction describes a late deceleration, which is gradual in onset and reflects uteroplacental insufficiency; its delayed timing, not the speed of the drop, defines it. A gradual descent that mirrors each contraction describes an early deceleration, which takes 30 seconds or more to reach a nadir that coincides with the contraction peak and reflects fetal head compression. Speed of onset is therefore the first feature to assess: an abrupt drop is variable, while a gradual drop is early or late depending on its timing. A deceleration lasting 2 minutes or more but less than 10 minutes is classified as prolonged.

B is correct.Antenatal corticosteroids such as betamethasone accelerate fetal lung maturation by stimulating surfactant production and structural lung development, which lowers the rate and severity of respiratory distress syndrome. The same course also reduces intraventricular hemorrhage and necrotizing enterocolitis and lowers neonatal mortality, which is why a single course is recommended between 24 0/7 and 33 6/7 weeks for patients at risk of birth within 7 days, including those with preterm premature rupture of membranes. The second 12 mg dose is given 24 hours after the first, and benefit is greatest when birth occurs at least 24 hours after the course begins. Lower cerebral palsy risk through fetal neuroprotection describes magnesium sulfate, not corticosteroids; magnesium is considered separately when birth before 32 weeks is anticipated. Less neonatal hypoglycemia is the opposite of what can occur, because late preterm steroid exposure is associated with increased neonatal hypoglycemia, and steroids are not given to prevent jaundice or feeding intolerance. Explaining the real benefits helps the patient understand why completing the course on time matters even when birth may come soon.

A is correct.When the heart rate is not rising and the chest is not moving during positive-pressure ventilation, ventilation is not effective, and NRP directs the team to the ventilation corrective steps summarized as MR. SOPA. The first two steps are M, mask adjustment to correct a leak by reapplying the mask with a firm seal, and R, reposition the airway by placing the head in the sniffing position. The team gives 5 breaths and reassesses chest movement after these steps before moving on to S, suction the mouth and nose, and O, open the mouth. Increasing the inflation pressure to 40 cm H2O is the P step, which comes only after the earlier steps fail; raising pressure through a leaking mask or a blocked airway will not improve ventilation and risks lung injury once the airway opens. Beginning chest compressions coordinated with ventilation is wrong because compressions are indicated only when the heart rate remains below 60 bpm after at least 30 seconds of ventilation that inflates the lungs. Here the heart rate is 70 bpm and ventilation has not yet been effective, so the priority is establishing chest movement.

B is correct.Withholding methylergonovine from a patient with severe-range blood pressure reflects nonmaleficence, the obligation to refrain from inflicting harm. Methylergonovine causes vasoconstriction and can trigger a hypertensive crisis, stroke, or seizure in a patient with preeclampsia, so giving it would expose her to a foreseeable injury. Declining to carry out a harmful order and seeking clarification is the classic nonmaleficence response, and it is also part of the nurse's professional accountability for safe medication administration. Beneficence is closely related but different: it requires actively taking positive steps to benefit the patient, such as massaging the fundus, emptying the bladder, or obtaining an alternative agent such as additional oxytocin or misoprostol. Those actions are beneficent, but the specific act of withholding the drug is about avoiding harm, not producing a benefit. Autonomy, respect for the patient's right to make informed decisions about her own care, is not the principle at work, because the patient did not make or refuse any choice in this situation; the nurse's judgment about medication safety drove the action. Distinguishing these principles helps nurses explain and document the reasoning behind difficult clinical decisions.