A 29-year-old woman, gravida 3 para 2, comes to the emergency department due to sudden-onset, heavy vaginal bleeding that has soaked through her clothes. The patient has had inconsistent prenatal care and says she is "about 8 months" pregnant. She has had some nonpainful contractions. Four years ago, she had a low transverse cesarean delivery. The patient smokes a pack of cigarettes a day and takes no medications. Temperature is 37 C (98.7 F), blood pressure is 96/70 mm Hg, pulse is 118/min, and respirations are 16/min. Fetal heart monitoring shows a baseline of 150/min, moderate variability, accelerations, and no decelerations. Tocodynamometry shows irregular contractions every 10-15 minutes. Which of the following is the most likely diagnosis in this patient?

Question

A 29-year-old woman, gravida 3 para 2, comes to the emergency department due to sudden-onset, heavy vaginal bleeding that has soaked through her clothes.  The patient has had inconsistent prenatal care and says she is "about 8 months" pregnant.  She has had some nonpainful contractions.  Four years ago, she had a low transverse cesarean delivery.  The patient smokes a pack of cigarettes a day and takes no medications.  Temperature is 37 C (98.7 F), blood pressure is 96/70 mm Hg, pulse is 118/min, and respirations are 16/min.  Fetal heart monitoring shows a baseline of 150/min, moderate variability, accelerations, and no decelerations.  Tocodynamometry shows irregular contractions every 10-15 minutes.  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

11ec25c8_d1e1_de00_bc81_e5a20e3785b0_MD0003_00 This patient most likely has placenta previa, which occurs when the placenta covers the cervix. Risk factors include multiparity, smoking, and prior cesarean delivery. Placenta previa is commonly diagnosed in asymptomatic patients during a routine 2nd-trimester ultrasound. In patients diagnosed with placenta previa, digital cervical examination and sexual intercourse are contraindicated, as they can trigger vaginal bleeding. However, bleeding may also occur spontaneously (as in this patient). Placenta previa Patients with symptomatic placenta previa have painless vaginal bleeding after 20 weeks gestation, ranging in severity from spotting to massive hemorrhage. Bleeding occurs as the placenta is sheared off the cervix, creating a partial detachment due to uterine irritability (eg, irregular, nonpainful contractions) which causes physiologic cervical changes (eg, effacement, dilation). Early in the disease process, bleeding is primarily maternal in origin; therefore, a reactive (ie, normal) fetal heart rate tracing is usually seen. However, continued maternal blood loss can eventually lead to fetal compromise, with deterioration of the fetal heart rate tracing. Management is dependent on maternal hemodynamic stability and fetal status. (Choice B) Placental abruption is vaginal bleeding from premature separation of the placenta from the uterine wall and typically causes constant abdominal pain, uterine tenderness, and fetal heart rate tracing abnormalities (eg, decelerations), which are not seen in this patient. Placental abruption (Choice C) Preterm labor presents with regular, painful contractions associated with cervical dilation and bloody show due to tearing of small cervical veins. Frank hemorrhage is not consistent with labor. (Choice D) Uterine rupture classically presents during labor in patients with a prior cesarean delivery with sudden onset of vaginal bleeding. However, patients also have intense abdominal pain, palpable fetal parts through the abdominal wall, and fetal heart rate abnormalities (eg, decelerations, bradycardia). Uterine rupture (Choice E) Vasa previa is characterized by fetal blood vessels that overlie the internal cervical os, making them vulnerable to injury with membrane rupture or labor. Although patients with vasa previa have painless vaginal bleeding (as in this patient), there is typically rapid deterioration of the fetal heart tracing as the hemorrhage is primarily of fetal origin. Vasa previa Educational objective: Placenta previa occurs when the placenta covers the cervix and typically presents with painless vaginal bleeding after 20 weeks gestation. Blood loss is primarily maternal in origin; therefore, fetal heart rate tracings are typically reactive early in the disease process. References: Critical analysis of risk factors and outcome of placenta previa. (http://www.ncbi.nlm.nih.gov/pubmed/20652281) Placental implantation abnormalities and risk of preterm delivery: a systematic review and metaanalysis. (http://www.ncbi.nlm.nih.gov/pubmed/26428506) Placenta previa and maternal hemorrhagic morbidity. (http://www.ncbi.nlm.nih.gov/pubmed/28140723)

A 29-Year-Old Woman, Gravida 3 Para 2, Comes to the Emergency