RISK-FACTORS FOR RECURRENCE OF HEMORRHAGIC ENDOVASCULITIS OF THE PLACENTA

Objective: To assess the potential for recurrence of placental hemorrh agic endovasculitis and to identify clinical or pathologic cofactors t hat might influence recurrence of this lesion or subsequent pregnancy outcome. Methods: Ninety-seven women with a placenta affected by hemor rhagic endovasculitis, who also had at least one placenta referred to the Michigan Placental Tissue Registry from a subsequent pregnancy, we re identified from 10,531 referrals between 1978 and 1988. Histologic slides from 209 placentas and clinical data from 211 infants (two sets of twins) from initial (first) and subsequent referrals were analyzed . Placentas were graded for the presence, extent, and severity of hemo rrhagic endovasculitis and chronic villitis of unknown etiology; for p lacental lesions indicative of hypertensive maternal vessel disease; a nd for intravascular nucleated erythrocytes and chorionic thrombi. Mat ernal data included age, gravidity, number of previous losses, and his tory of toxemia or hypertension. All data were analyzed for significan ce using chi(2) and t tests. Outcome assessment was based on recurrenc e of hemorrhagic endovasculitis and infant viability with the second r eferral. Results: With first referrals, 80 of 98 infants (81.6%) were stillborn. Among second referrals, 26 of 98 infants (26.5%) were still born. Hemorrhagic endovasculitis recurred in 28 second placentas (28.9 %); of these, 18 infants (64.3%) were stillborn. Higher rates of recur rence were found with progressively higher first-referral chronic vill itis severity scores (P < .02), higher hypertensive placental lesion s cores (P < .001), and first referrals with a history of toxemia or hyp ertension (P < .02). Recurrence of hemorrhagic endovasculitis was high er in patients with two or more of these factors in first referrals (P < .001). Subsequent stillbirth was more frequent with progressively h igher first-referral hypertensive placental lesion scores (P < .01) an d in first placentas with two or more risk factors (P = .064). Hemorrh agic endovasculitis severity scores, intravascular nucleated erythrocy tes, and chorionic thrombi were associated with stillbirth in index pr egnancies only. Maternal age, gravidity, or history of prior losses we re not predictive. Conclusions: Placental hemorrhagic endovasculitis i s associated with pregnancy loss and can recur in some patients. Inter relations among placental hemorrhagic endovasculitis, chronic villitis , maternal hypertension, and adverse outcomes in subsequent pregnancie s are apparent. This information may be useful in patient counseling. (C) 1997 by The American College of Obstetricians and Gynecologists.