Preeclampsia More Than 1 Disease

Abstract

In this issue of Hypertension , Rasmussen and Irgens provide strong support for the relationship of preeclampsia and intrauterine growth restriction (IUGR). They also provide data that support but also some that argue against the concept that the pregnancy complication, preeclampsia, may be more than one disease.1 In previous studies these authors demonstrated that women who have had a growth-restricted infant without preeclampsia are more likely to have preeclampsia in a subsequent pregnancy.2 Those data and similar findings in the current study support pathological findings indicating the similarity of IUGR and preeclampsia.3 In preeclampsia, IUGR and interestingly also in about one third of cases of preterm birth,4 the maternal myometrial and decidual vessels perfusing the placental site do not undergo the normal remodeling of pregnancy. In normal pregnancy trophoblastic invasion is associated with a greatly increased diameter and removal of vascular smooth muscle from the wall of these vessels. This results in large diameter, flaccid, unresponsive tubes that greatly increase placental perfusion. These changes are not present in pregnancies complicated by IUGR, preeclampsia, and some with preterm births. Implicit in the current study is the concept that preterm birth as well as IUGR is related to subsequent preeclampsia. Although preterm birth is not assessed directly, the effect of low birth weight (IUGR and preterm birth) was greater than the effect of IUGR alone. In a far smaller study our group was able to more directly support the relationship of preterm birth and preeclampsia, as women with early onset preeclampsia were more likely to have preterm birth in a subsequent nonpreeclamptic pregnancy.5 The current study extends the prior observation of the relationship of IUGR and preeclampsia but also raises other interesting points. In this larger study the authors were …