A 32-year-old primigravida at 28 weeks gestation comes to the emergency department due to painful contractions that began 2 hours ago and are now occurring every 5 minutes. She has had no leakage of fluid or vaginal bleeding; fetal movement is normal. The patient was last seen in the office a few days ago for a routine prenatal visit; she had some increasing pelvic pressure, but her pregnancy has otherwise been uncomplicated. She has no chronic medical conditions, and her only medications are a daily prenatal vitamin and folate supplement. Temperature is 37 C (99 F), blood pressure is 114/60 mm Hg, and pulse is 80/min. The fetal heart rate tracing has moderate variability, multiple accelerations, and no decelerations. Tocodynamometry shows contractions every 5 minutes. On digital pelvic examination, the cervix is 3 cm dilated and 90% effaced with the fetus in vertex presentation. Betamethasone and indomethacin are administered. Which of the following is the best next step in management of this patient?

Question

A 32-year-old primigravida at 28 weeks gestation comes to the emergency department due to painful contractions that began 2 hours ago and are now occurring every 5 minutes.  She has had no leakage of fluid or vaginal bleeding; fetal movement is normal.  The patient was last seen in the office a few days ago for a routine prenatal visit; she had some increasing pelvic pressure, but her pregnancy has otherwise been uncomplicated.  She has no chronic medical conditions, and her only medications are a daily prenatal vitamin and folate supplement.  Temperature is 37 C (99 F), blood pressure is 114/60 mm Hg, and pulse is 80/min.  The fetal heart rate tracing has moderate variability, multiple accelerations, and no decelerations.  Tocodynamometry shows contractions every 5 minutes.  On digital pelvic examination, the cervix is 3 cm dilated and 90% effaced with the fetus in vertex presentation.  Betamethasone and indomethacin are administered.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec25c8_da78_811c_bc81_7fd1db15309f_MD0003_00 This patient with frequent, regular contractions causing cervical dilation and effacement at <37 weeks gestation is in preterm labor. Management depends on gestational age, with more interventions required at earlier gestations due to greater neonatal morbidity and mortality. Patients at <32 weeks gestation are very preterm and therefore require the following: Corticosteroids (eg, betamethasone) to promote fetal lung maturity (ie, decrease the risk of neonatal respiratory distress syndrome). Penicillin to prevent vertical transmission of group B Streptococcus (GBS), which occurs more frequently at preterm gestations. Therefore, prophylaxis is required in all preterm patients with an unknown or positive GBS status. Tocolysis (ie, contraction inhibition) to temporarily delay delivery and allow time for other interventions. Indomethacin is the first-line treatment at <32 weeks gestation because of its high efficacy and few maternal adverse effects; as gestational age increases, however, indomethacin poses greater fetal risks (eg, premature closure of the ductus arteriosus). Therefore, nifedipine is preferred between 32 and 34 weeks gestation (Choice B). Magnesium sulfate to decrease the risk of cerebral palsy, which is highest in infants delivered at <32 weeks gestation. The neuroprotective mechanism of magnesium sulfate likely is due to stabilization of fetal neuronal membranes in utero or anti-inflammatory effects. Magnesium sulfate is not typically administered for fetal neuroprotection at ≥32 weeks gestation because of limited data that it prevents cerebral palsy at later gestational ages. (Choice C) Observation and repeat cervical examination are appropriate management for suspected false labor (eg, irregular contractions with no cervical dilation) but inappropriate for active preterm labor. (Choice D) Progesterone decreases the rates of preterm delivery in patients with prior preterm delivery or an incidental short cervix (ie, ≤2.5 cm on ultrasound). It likely works by decreasing prostaglandin production, thereby maintaining uterine muscle relaxation. However, it cannot halt acute preterm labor because it has no acute tocolytic effect. (Choice E) Sonographic cervical length measurement can be used to triage patients with preterm contractions because shorter lengths correlate with increased risk for preterm delivery. However, testing would not change management for this patient who is already high risk based on her clinical presentation. Educational objective: Patients in preterm labor at <32 weeks gestation require corticosteroids, penicillin, tocolysis, and magnesium sulfate to decrease neonatal morbidity and mortality associated with preterm delivery. References: Antenatal exposure to magnesium sulfate and neuroprotection in preterm infants. (http://www.ncbi.nlm.nih.gov/pubmed/21575805)

A 32-Year-Old Primigravida at 28 Weeks Gestation Comes to the Emergency