A 40-year-old woman, gravida 3 para 2, at 33 weeks gestation comes to labor and delivery due to leakage of fluid. The patient has had intermittent leakage of clear vaginal fluid for the past few hours but no vaginal bleeding. She has had some irregular contractions for the past few weeks, but they are nonpainful. Fetal movement has been normal. The patient has type 2 diabetes mellitus and had polyhydramnios on her most recent fetal ultrasound. Temperature is 36.7 C (98 F), blood pressure is 120/70 mm Hg, and pulse is 70/min. BMI is 35 kg/m². Fetal heart rate tracing shows a baseline of 140/min with moderate variability and multiple accelerations. Tocodynamometer reveals contractions every 15-18 minutes. The uterus is nontender. Speculum examination shows a closed cervix and clear fluid in the posterior fornix of the vagina. There is ferning on microscopy. A transabdominal ultrasound reveals a fetus in vertex presentation surrounded by minimal amniotic fluid; the deepest vertical pocket is 1 cm. Which of the following is the best next step in management of this patient?

Question

Quizplus · Accepted Answer

Explanation: 11ec25c8_da7f_10d4_bc81_7b8bb2565681_MD0003_00 This patient's vaginal pooling of nitrazine-positive (ie, alkaline) amniotic fluid with ferning on microscopy is consistent with preterm prelabor rupture of membranes (PPROM): rupture of membranes at <37 weeks gestation prior to the onset of labor (as in this patient who still has irregular contractions and a closed cervix). Risk factors include prior PPROM as well as conditions that overdistend or weaken the membranes, making them prone to rupture (eg, polyhydramnios, genitourinary infection, antepartum bleeding). Management of PPROM depends on gestational age and maternal-fetal status; benefits of further fetal development in utero (eg, fetal lung maturity) are balanced against risks for maternal complications (eg, intraamniotic infection). In the absence of complications, patients with PPROM at <34 weeks gestation require inpatient expectant management with: Prophylactic latency antibiotics to prevent fulminant intraamniotic infection, thereby increasing time between rupture and delivery (ie, "latency") Corticosteroids (eg, betamethasone) to decrease neonatal respiratory distress syndrome risk Fetal surveillance (eg, nonstress tests, fetal growth ultrasounds) Patients with PPROM are typically delivered at 34 weeks gestation (when the risk of complications outweighs the neonatal benefit of continuing pregnancy); however, if complications develop (eg, placental abruption) then earlier delivery is indicated. (Choice A) Amnioinfusion treats variable fetal heart rate decelerations in labor. It is not indicated in PPROM for oligohydramnios treatment (ie, replacing fluid volume lost from PPROM) because it does not improve fetal outcomes (eg, pulmonary hypoplasia). (Choices B and C) Tocolysis (eg, nifedipine) temporarily halts contractions to delay delivery. Tocolysis is contraindicated in PPROM because contractions often indicate a complication (eg, intraamniotic infection, placental abruption) that requires delivery or intervention. Magnesium sulfate is given for fetal neuroprotection (ie, cerebral palsy risk reduction) for preterm deliveries at less than 32 weeks gestation. This patient is at 33 weeks gestation. (Choice E) Vaginal progesterone decreases the risk of preterm delivery in patients with an incidental shortened cervix (≤25 mm). It is not used in the management of PPROM. Educational objective: Uncomplicated preterm prelabor rupture of membranes at <34 weeks gestation is managed expectantly with prophylactic latency antibiotics, corticosteroids, and inpatient monitoring. Delivery is at 34 weeks gestation or sooner if complications develop (eg, intraamniotic infection, placental abruption). References: ACOG practice bulletin no. 188 summary: prelabor rupture of membranes. (http://www.ncbi.nlm.nih.gov/pubmed/29266069)

A 40-Year-Old Woman, Gravida 3 Para 2, at 33 Weeks