A nurse is assessing a client who is in labor.
Which of the following findings should the nurse expect?

The nurse should anticipate the provider will prescribe terbutaline and betamethasone.

Rationale for correct answers:
Terbutaline is a beta-2 adrenergic agonist that relaxes uterine smooth muscle by increasing intracellular cyclic AMP, reducing calcium influx, and thus inhibiting contractions. It is commonly used as a tocolytic to delay preterm labor, allowing time for fetal maturation. Betamethasone is a corticosteroid given to accelerate fetal lung maturity by stimulating surfactant production in the fetal lungs, which significantly reduces the risk of respiratory distress syndrome in neonates born between 24 and 34 weeks gestation. The normal fetal fibronectin level is ≤0.05 mcg/mL; a value above this, as in this client (0.09 mcg/mL), indicates increased risk of preterm birth, supporting the use of these medications.

Rationale for incorrect answers:
Oxytocin (Response 1) stimulates uterine contractions via oxytocin receptors, promoting labor induction or augmentation. Administering oxytocin before term or in preterm labor is contraindicated because it can worsen contractions, precipitating early delivery.

Betamethasone (Response 1) is not used to stop contractions but to promote fetal lung maturity. It does not act as a tocolytic; thus, it is not prescribed alone to delay labor.

Misoprostol (Response 1) is a prostaglandin E1 analog that promotes cervical ripening and uterine contractions, making it inappropriate in preterm labor management, where delaying labor is the goal.

Oxytocin (Response 2) serves no purpose in fetal lung maturation and instead promotes contractions; thus, it is contraindicated here.

Ondansetron (Response 2) is an antiemetic without effects on uterine activity or fetal lung maturity; its use is unrelated to preterm labor management.

Misoprostol (Response 2) induces labor and cervical changes and is contraindicated in preterm labor where prolonging pregnancy is desired.

Take-home points:

• Terbutaline delays preterm labor by relaxing uterine muscles, buying critical time for fetal development.
• Betamethasone accelerates fetal lung maturity by stimulating surfactant production, reducing neonatal respiratory complications.
• Oxytocin and misoprostol induce labor and are contraindicated in preterm labor management aiming to delay delivery.
• Fetal fibronectin levels above 0.05 mcg/mL indicate increased risk of preterm birth, guiding tocolytic and steroid therapy.

Choice A rationale

Uric acid levels in preeclampsia can be elevated due to decreased renal clearance and increased production, often exceeding the normal range of 2.7 to 7.3 mg/dL. A value of 7.5 mg/dL is slightly elevated, which is a common finding in preeclampsia and does not typically contraindicate the administration of labetalol, an antihypertensive medication. It reflects disease progression but does not pose an immediate risk regarding medication administration.

Choice B rationale

Labetalol is a beta-blocker that reduces heart rate and blood pressure. A heart rate of 54/min is below the normal adult resting heart rate range (typically 60-100 beats/min) and indicates bradycardia. Administering labetalol to a client with pre-existing bradycardia could further depress the heart rate, potentially leading to symptomatic bradycardia, decreased cardiac output, and inadequate tissue perfusion, thus requiring the nurse to withhold the medication.

Choice C rationale

A fetal heart rate (FHR) of 112/min is within the normal range for a fetus (typically 110-160 beats/min). While labetalol can rarely cause fetal bradycardia, a baseline FHR of 112/min does not contraindicate its administration. The primary concern with labetalol in preeclampsia is the maternal hemodynamic response, and this FHR value does not indicate an immediate fetal distress that would preclude the medication.

Choice D rationale

A BUN level of 23 mg/dL is slightly elevated above the normal range of 10 to 20 mg/dL, often seen in preeclampsia due to impaired renal function. While this indicates renal involvement, it does not contraindicate the administration of labetalol. Labetalol is primarily metabolized by the liver, and while caution is advised in renal impairment, this BUN level alone does not warrant withholding the medication.