A 31-year-old woman, gravida 2 para 1, at 36 weeks gestation comes to the emergency department due to regular menstrual-like cramping and low back pain. She reports no leakage of fluid or vaginal bleeding; fetal movement is normal. The patient's pregnancy has been uncomplicated. Her first pregnancy resulted in an uncomplicated vaginal delivery at 39 weeks gestation. She has no medical problems and had an appendectomy at age 15. She takes a prenatal vitamin daily. The patient has no known drug allergies. Temperature is 36.7 C (98 F), blood pressure is 100/70 mm Hg, and pulse is 94/min. The fetal heart rate monitor shows a baseline of 145/min, moderate variability, and no decelerations. The tocometer shows contractions every 3-4 minutes. Pelvic examination shows the cervix to be 4 cm dilated and 50% effaced. Ultrasound confirms a vertex presentation and an occiput posterior position. Prenatal laboratory results are notable for A, Rh(D)-negative blood type and a recent negative group B Streptococcus culture. Which of the following is the best next step in management of this patient?

Question

A 31-year-old woman, gravida 2 para 1, at 36 weeks gestation comes to the emergency department due to regular menstrual-like cramping and low back pain.  She reports no leakage of fluid or vaginal bleeding; fetal movement is normal.  The patient's pregnancy has been uncomplicated.  Her first pregnancy resulted in an uncomplicated vaginal delivery at 39 weeks gestation.  She has no medical problems and had an appendectomy at age 15.  She takes a prenatal vitamin daily.  The patient has no known drug allergies.  Temperature is 36.7 C (98 F), blood pressure is 100/70 mm Hg, and pulse is 94/min.  The fetal heart rate monitor shows a baseline of 145/min, moderate variability, and no decelerations.  The tocometer shows contractions every 3-4 minutes.  Pelvic examination shows the cervix to be 4 cm dilated and 50% effaced.  Ultrasound confirms a vertex presentation and an occiput posterior position.  Prenatal laboratory results are notable for A, Rh(D)-negative blood type and a recent negative group B Streptococcus culture.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c040_4292_8f63_b15406c11f0e_MD0005_00 At <37 weeks gestation, this patient has regular contractions and a dilated cervix, a presentation consistent with preterm labor. Risk factors for preterm labor include a history of prior preterm delivery, multiple gestation, and uterine malformations. The management of preterm labor is dependent on gestational age; at 34 to 36 6/7 weeks gestation, management includes penicillin and antenatal corticosteroids (eg, betamethasone). Infants born in the late preterm period (34 to 36 6/7 weeks gestation) are at increased risk for neonatal complications (eg, hypothermia, hypoglycemia, respiratory distress) compared with infants born at term. Administration of antenatal corticosteroids to patients at risk for late preterm delivery is associated with a decreased risk for neonatal respiratory complications (eg, transient tachypnea of the newborn, bronchopulmonary dysplasia) and a decreased neonatal intensive care admission rate. Late prenatal antenatal corticosteroids can cause a transient neonatal hypoglycemia; however, there is no associated sequela. Current recommendations include administration of intramuscular corticosteroids to late preterm patients at risk for delivery within the next 7 days. Group B Streptococcus (GBS) can cause neonatal infection (eg, sepsis, meningitis) by vertical transmission; prevention is provided by maternal treatment during labor. Penicillin is indicated at 34 to 36 6/7 weeks gestation for GBS prophylaxis in laboring patients who have a positive or an unknown GBS culture result. (Choice A) An amniotomy is a technique for labor augmentation (eg, increasing contraction strength and frequency). Labor augmentation is not used in patients in preterm labor who do not have an indication for expedited delivery (eg, chorioamnionitis). Expectant management (without augmentation) also provides corticosteroids additional time to take effect. amniotomy (Choice B) Cesarean delivery is indicated for arrest of labor, malpresentation (eg, breech presentation), or fetal heart rate tracing abnormalities (eg, late decelerations). This patient has a vertex presentation and normal fetal heart rate. breech presentation late decelerations vertex presentation (Choice D) Rho(D) immunoglobulin prevents alloimmunization in Rh-negative patients who deliver Rh-positive infants. Fetal Rh status is determined after delivery and Rho(D) immunoglobulin can be administered up to 72 hours postpartum. (Choice E) After 34 weeks gestation, tocolytics (eg, nifedipine) are contraindicated as the risks of perinatal morbidity and mortality no longer outweigh the risks of maternal tocolytic exposure (eg, pulmonary edema, hypotension). Educational objective: Preterm labor at 34 to 36 6/7 weeks gestation is managed with penicillin and intramuscular corticosteroid (eg, betamethasone) administration. Corticosteroids reduce the perinatal morbidity and mortality associated with preterm birth. References: Antenatal betamethasone for women at risk for late preterm delivery. (http://www.ncbi.nlm.nih.gov/pubmed/26842679) Committee opinion no.677: antenatal corticosteroid therapy for fetal maturation. (http://www.ncbi.nlm.nih.gov/pubmed/27661658) Implementation of the use of antenatal corticosteroids in the late preterm birth period in women at risk for preterm delivery. (http://www.ncbi.nlm.nih.gov/pubmed/26992737)

A 31-Year-Old Woman, Gravida 2 Para 1, at 36 Weeks