PLATELET COUNT AND PLATELET-ASSOCIATED IgG IN 123 CONSECUTIVE PREGNANCIES: RELATIONSHIP MATERNAL ACTORS TO NE NATAL PLATELET COUNT

Abstract

Automated cell counting has brought to our attention the increased incidence of thrombocytopenia (TP) in pregnant women. This observation prompted us to evaluate 123 consecutive pregnancies for maternal and neonatal platelet counts (PC) and for maternal platelet-associated IgG (PAIg). PAIg was measured by solid phase RIA with Protein A. Thirty-two women (26%) were TP (PC: 43K-149K, mean±SD=121K±25) during the prenatal period (6), the perinatal period (12), or throughout pregnancy (14). Twenty-five (78%) TP women had elevated levels of PAIg (3.57-38.81ng/106 platelets, mean±SD=9.10±8.14) at least once during pregnancy when compared with 23 non-pregnant women of child-bearing age (0.58-3.40, mean±SD=2.10±0.67). Fifty-one (56%) of the 91 women who were never TP had elevated PAIg (3.55-32.39, mean±SD=6.68±4.20). Two (7%) of 30 infants born to TP women were TP at the time of delivery (initial PC: 83K,110K). Perinatal PAIg was elevated in one of these mothers and normal in the other. Six (7%) of 81 infants born to women who were never TP were TP (initial PC: 109K-149K). Perinatal PAIg was elevated in 2 of these mothers, normal in 3, and not done in 1. These studies indicate that: 1) There is a high incidence (26%) of TP in pregnant women, 2) There is a high incidence of elevated PAIg in pregnant women, whether they are never TP (56%) or TP (78%), 3) Seven percent of neonates are born TP, and 4) Maternal PC and PAIg do not predict which infants will be born with low platelet counts.