Perinatal Outcome of Pregnancies Complicated by Placenta Accreta

OBJECTIVE: The purpose of the study was to characterize the perinatal outcome of pregnancies complicated by placenta accreta. METHODS: We conducted a case-control analysis of all deliveries between the years 1990 and 2000 that were complicated by placenta accreta. Perinatal variables included in the analysis were gestational age at delivery, birth weight, Apgar scores, and perinatal mortality. Statistical analysis was performed using both the unpaired and paired approach. P <.05 was considered significant. RESULTS: The study encompassed 34,450 deliveries, from which 310 cases of placenta accreta were diagnosed (0.9%) and compared with 310 matched controls. In the pregnancies complicated by placenta accreta, we found a statistically significant increase in preterm deliveries (10.7% versus 1%, P <.001, odds ratio 12.1, 95% confidence interval 3.7-39.9) and small-for-gestational-age babies (27.3% versus 14%, P <.001, odds ratio 5.05, 95% confidence interval 1.46-3.28). CONCLUSION: Pregnancies complicated by placenta accreta are at increased risk for perinatal adverse outcome. We speculate that these findings may arise from pathological implantation of the placenta, resulting in interference with normal fetal growth.