Preeclampsia and cerebral palsy in low-birth-weight and preterm infants: Implications for the current "ischemic model" of preeclampsia

Objective. One of the prevailing hypotheses for the pathogenesis of preeclampsia is the "ischemic model." It assumes that reduced uteroplacental perfusion is the primary step and the point of convergence of diverse pathogenic processes in the development of preeclampsia. One might expect a fetus under such "ischemic conditions" to be at an increased risk of later development of cerebral palsy (CP). The objective of this study was to test the hypothesis that maternal preeclampsia increases the risk of CP in preterm and low-birth-weight infants. Methods. A meta-analysis was performed based on published articles identified by searching computerized databases (MEDLINE, EMBASE, CINAHL. Current Contents. Biological Abstracts. and Dissertation Abstracts) from 1966 through 1999. Ten observational studies on the association between preeclampsia and CP were identified based on prespecified inclusion criteria. Two independent reviewers extracted data and assessed the methodological quality of eligible articles. Odds ratios (OR) of CP for preeclampsia from individual studies were pooled. Main Outcome Measure. Cerebral palsy. Results. In case-control studies, preeclampsia was associated with a statistically significant decreased risk of CP [pooled adjusted OR, 0.50; 95% confidence interval (CI), 0.33-0.81: p < 0.01]. In cohort studies. preeclampsia was associated with a nonstatistically significant reduced risk of CP (pooled OR, 0.91;95% CI, 0.35-2.41: p > 0.05). Conclusions. Preeclampsia may be associated with a decreased risk of CP in preterm and low-birth-weight infants. This challenges the currently held belief that reduced uteroplacental perfusion is the unique pathophysiological process in preeclampsia.