Diagnosis of sickling by placental examination: Geographic differences in incidence

Abstract

When the placenta separates from the uterine wall, the resulting hypoxia creates a natural sickling preparation of the trapped erythrocytes in the placenta. A histologic examination of 2,117 consecutive placentas from Negro women enrolled in the Collaborative Study showed a sickling incidence of 9.4 per cent. Sickling rates in the southern institutions (11.0 to 12.2 per cent) were higher than in the northern institutions (6.1 to 8.4 per cent). It is postulated that these geographic differences in sickling rates may indicate increased admixture of Caucasian blood among northern Negroes. Permanent histologic sections of the placenta offer the advantages of retrospective study, uniformity of technique, and reconfirmation of diagnosis which are not possible with sickle-cell preparations on peripheral blood. When the placenta separates from the uterine wall, the resulting hypoxia creates a natural sickling preparation of the trapped erythrocytes in the placenta. A histologic examination of 2,117 consecutive placentas from Negro women enrolled in the Collaborative Study showed a sickling incidence of 9.4 per cent. Sickling rates in the southern institutions (11.0 to 12.2 per cent) were higher than in the northern institutions (6.1 to 8.4 per cent). It is postulated that these geographic differences in sickling rates may indicate increased admixture of Caucasian blood among northern Negroes. Permanent histologic sections of the placenta offer the advantages of retrospective study, uniformity of technique, and reconfirmation of diagnosis which are not possible with sickle-cell preparations on peripheral blood.