The efficacy of the placental biopsy.

Abstract

Our purpose was to determine the sensitivity and specificity of pathologic diagnoses made from a placental biopsy specimen compared with diagnoses made from a complete placental examination. Biopsy was performed on 200 singleton placentas with a 16-gauge Rutner biopsy needle shortly after delivery. The biopsy specimens and placentas were evaluated by standard placental pathologic criteria. The presence of villous edema on the biopsy specimen led to the diagnosis of placental villous edema with a sensitivity of 51% and specificity of 86%, yielding a positive predictive value of 0.97. The sensitivity of the biopsy diagnosis of "increased syncytial knots" was 86%, whereas the specificity was 82%, yielding a positive predictive value of 0.90. Because a placental biopsy specimen after delivery is reasonably sensitive for diagnosing villous abnormalities that reflect acute and chronic stresses to the placenta, it may be useful to develop a placental biopsy that can be performed safely during pregnancy. Such a biopsy could be the basis for the rational treatment of some diseases of pregnancy.