HISTOLOGIC EVIDENCE OF OLD INTRAUTERINE BLEEDING IS MORE FREQUENT IN PREMATURITY

OBJECTIVE: Our purpose was to study the incidence and location of hist ologic evidence of intrauterine bleeding in preterm and term placentas . STUDY DESIGN: A total of 462 consecutive placentas delivered at < 32 weeks' gestation, from which cases of placenta previa, stillbirth, an d multiple gestation were excluded, were compared with 108 consecutive term placentas (with similar exclusion criteria) in regard to the pre sence of hemosiderin in decidua of basal plate or placental membranes. Of the 462 preterm cases, 448 charts made specific reference to the p resence or absence of vaginal bleeding. Bloody show alone was not cons idered bleeding. The blinded scoring of lesions (including acute ascen ding infection, uteroplacental vascular pathologic processes and relat ed ischemic damage, chronic inflammation, and coagulation related lesi ons) was analyzed by contingency tables (p < 0.05 significant). RESULT S: A total of 196 of 462 (43%) preterm placentas had any decidual hemo siderin compared with one of 108 (0.8%) at term (p < 0.00001). Among t he preterm cases, hemosiderin was significantly more common in preecla mpsia (45/76, 60%) and in cases clinically diagnosed as nonhypertensiv e abruptio placentae (21/33, 64%) than in premature membrane rupture ( 72/192, 37.5%) and preterm labor (58/161, 36%, p < 0.003). The inciden ce of placental lesions in preterm cases with extraplacental membrane hemosiderin was not different than it was in cases without hemosiderin . Placental lesions related to basal-plate decidual hemosiderin in the preterm cases were villous infarct (p < 0.0001), uteroplacental vesse ls with absence of physiologic change (p < 0.003) and increased number s of circulating nucleated erythrocytes (p < 0.0007), uteroplacental t hrombosis (p < 0.0001), and villous fibrosis (p < 0.0001) and hypovasc ularity (p < 0.0001). Among the preterm cases, 23 of 48 (48%) with fir st-trimester bleeding, 33 of 66 (50%) with second-trimester bleeding, and 31 of 64 (48%) with multiple episodes of bleeding had decidual hem osiderin (p < 0.0001). A clinical history of gestational bleeding was significantly less common in cases of preterm preeclampsia with histol ogic evidence of bleeding (four of 73, 5.5%) than in nonhypertensive a bruptio placentae (18/31, 58%), premature rupture of membranes (52/183 , 28%), or preterm labor (31/161, 19%, p < 0.0001). Hemosiderin was no t related to clinical bleeding < 72 hours of delivery (p > 0.20). CONC LUSIONS: Decidual bleeding is common in all clinical types of preterm birth and is most common in preterm preeclampsia and nonhypertensive a bruptio placentae. A clinical history of bleeding is not correlated wi th the presence of decidual hemosiderin. Bleeding in the basal plate i s related to histologic evidence of chronic uteroplacental vascular pa thologic processes, which in cases of spontaneous prematurity (prematu re rupture of membranes, preterm labor, nonhypertensive abruptio place ntae) may be associated with decidual bleeding which occasionally may be clinically manifested as gestational bleeding.