Clinical context Preterm labor at
32 3/7 weeks with
cervical dilation 3 cm, intact membranes, no bleeding or infection, and a normal fetal heart rate tracing places this patient in the window where two interventions work together: accelerate fetal lung maturity and temporarily reduce contractions so the steroid has time to act.
Why the correct pair is betamethasone and nifedipine Antenatal corticosteroids are recommended when delivery is anticipated within
7 days between
24 0/7 and 33 6/7 weeks. At
32 3/7 weeks, this patient is still within that range, and with regular contractions plus cervical change, birth within a week is a realistic concern.
Betamethasone is the corticosteroid given to reduce neonatal respiratory distress, intraventricular hemorrhage, and necrotizing enterocolitis. A short course of a tocolytic can be used for up to
48 hours to allow the corticosteroid to achieve its effect.
Nifedipine, a calcium channel blocker, is a first-line tocolytic for this purpose because it relaxes uterine smooth muscle with a favorable maternal side-effect profile.
The goal of tocolysis here is not to stop labor until term, but to buy time for the steroid to work.
Why the other options are incorrect
| Option | Medication pair | Why it is not the best answer |
|---|
| 1 | Betamethasone and indomethacin | Indomethacin, an NSAID, is generally limited to gestations before 32 weeks because of fetal risks such as premature ductus arteriosus closure and oligohydramnios. At 32 3/7 weeks, it is not the preferred tocolytic. |
| 2 | Magnesium sulfate and nifedipine | Magnesium sulfate for fetal neuroprotection is mainly indicated when birth is expected before 32 weeks. This patient is already past that threshold, so magnesium is not the priority medication. Nifedipine alone does not address fetal lung maturity. |
| 4 | Betamethasone and oral terbutaline until 37 weeks | Long-term or maintenance oral tocolysis is not recommended. Terbutaline also carries significant maternal cardiovascular risks. Tocolysis should be limited to 48 hours for steroid benefit, not continued for weeks. |
Pathophysiology and nursing application Preterm labor reflects premature activation of the same inflammatory and hormonal pathways that normally initiate term labor. Contractions plus cervical change define active preterm labor, and once the cervix is
3 cm dilated, the process is already established. The nurse should anticipate orders that address two separate problems: fetal immaturity and ongoing uterine activity.
Corticosteroids and tocolytics are complementary, not interchangeable—one matures the fetus, the other temporarily quiets the uterus.
Watch out! Do not interpret nifedipine as a long-term solution. Its role is limited to a short window, typically
48 hours, while betamethasone is administered. After that, if labor progresses, delivery is allowed to proceed.
Key point! The gestational age cutoff matters. At
32 3/7 weeks, the patient is past the neuroprotection window for magnesium sulfate and past the safe use window for indomethacin, but still within the corticosteroid benefit window. This is why option 3 is the only pair that fits all the criteria.
Monitoring priorities for the nurse After betamethasone is given, monitor maternal blood glucose because transient hyperglycemia is common. With nifedipine, assess maternal blood pressure and heart rate, and watch for headache, flushing, or dizziness. Continue fetal heart rate monitoring and observe for signs of labor progression, rupture of membranes, vaginal bleeding, or infection, since any of these would change the plan.
The intact membranes and absence of infection in this scenario support the decision to attempt short-term tocolysis rather than proceeding directly to delivery.