A 26-year-old woman, gravida 1 para 0, at 36 weeks gestation comes to the office for a routine prenatal visit. She has had no headaches, changes in vision, or right upper quadrant pain. Fetal movement is normal. The patient has no chronic medical conditions, and her pregnancy has been uncomplicated. Blood pressure today is 150/100 mm Hg, and a repeat measurement is 154/102 mm Hg. All other vital signs are normal. Urinalysis shows 2+ protein. This patient's condition is most likely due to decreased activity of which of the following?

Question

A 26-year-old woman, gravida 1 para 0, at 36 weeks gestation comes to the office for a routine prenatal visit.  She has had no headaches, changes in vision, or right upper quadrant pain.  Fetal movement is normal.  The patient has no chronic medical conditions, and her pregnancy has been uncomplicated.  Blood pressure today is 150/100 mm Hg, and a repeat measurement is 154/102 mm Hg.  All other vital signs are normal.  Urinalysis shows 2+ protein.  This patient's condition is most likely due to decreased activity of which of the following?

Quizplus · Accepted Answer

11ec160b_3b20_81bc_9249_23bcfa8912bd_MD0001_00 This patient has preeclampsia, which is defined as new onset hypertension during pregnancy (systolic ≥140 mm Hg or diastolic ≥90 mm Hg) with proteinuria and/or signs of end-organ damage (eg, headache, renal insufficiency). Although patients typically develop symptoms in the third trimester, the disease process usually begins during the first trimester with abnormal placental development. In patients who develop preeclampsia, early cytotrophoblast invasion is abnormal; as a result, the maternal spiral arteries that supply blood to the fetoplacental unit are abnormally underdeveloped and become high resistance, low perfusion vessels. This decrease in perfusion leads to chronic placental ischemia, which triggers increased release of antiangiogenic factors throughout the maternal circulation. These antiangiogenic factors bind and decrease proangiogenic factors such as vascular endothelial growth factor (VEGF) and placental growth factor. The overall effect is inhibited angiogenesis and widespread maternal endothelial cell dysfunction, resulting in dysregulated vascular tone (eg, vasospasm, hypertension), abnormally increased vascular permeability (eg, proteinuria), and decreased end-organ perfusion (eg, renal insufficiency). (Choices A and D) Endothelin and thromboxane A2 (TXA2) are potent vasoconstrictors. Therefore, their activity is typically increased, not decreased, in preeclampsia due to increased endothelin and TXA2 production by dysfunctional endothelial cells. (Choices B and C) Decreased human chorionic gonadotropin and prolactin levels are associated with first-trimester pregnancy loss (ie, spontaneous abortion); however, activity levels of neither hormone are related to preeclampsia. Educational objective: Preeclampsia is new-onset hypertension (systolic ≥140 mm Hg or diastolic ≥90 mm Hg) with proteinuria and/or signs of end-organ damage (eg, renal insufficiency). Preeclampsia is associated with widespread maternal endothelial dysfunction, which occurs due to increased antiangiogenic factor release and decreased proangiogenic factor activity (eg, vascular endothelial growth factor). __________ References: Mechanisms of endothelial dysfunction in hypertensive pregnancy and preeclampsia. (http://www.ncbi.nlm.nih.gov/pubmed/27451103)

A 26-Year-Old Woman, Gravida 1 Para 0, at 36 Weeks