Second-trimester placental changes associated with elevated maternal serum α-fetoprotein

摘要: Measuring maternal serum alpha-fetoprotein (AFP) levels in the second trimester is an effective screening test for identifying pregnancies at increased risk neural tube defects. In absence of a defect there are many nonpathologic and pathologic causes elevated AFP including underestimated gestational age, twin gestation, impending fetal death, rare malformations. this series, intraplacental sonolucent spaces were detected significant percentage with any other cause elevation. It postulated that these cystic conduit transfer blood into circulation, thus accounting elevation serum.