Does previa location matter? Surgical morbidity associated with location of a placenta previa.

OBJECTIVE: To evaluate the effect of placenta previa location (anterior vs posterior) on cesarean morbidity.

STUDY DESIGN: Retrospective cohort of women undergoing cesarean for placenta previa. The rate of hysterectomy and blood transfusion in the setting of anterior previa was compared with posterior previa. Planned stratified analysis based on delivery history was performed. Logistic regression was performed to control for potential confounders.

RESULT: Two hundred and eighty-five women undergoing cesarean delivery for placenta previa were identified. Women undergoing primary cesareans with an anterior previa had higher rates of blood transfusion (adjusted odds ratio (aOR) 3.13 95% confidence interval (CI) (1.18 to 8.36) and hysterectomy (7.4% vs 0, P=0.001) compared with those with a posterior previa; similarly, women undergoing repeat cesarean with anterior previa had higher rates of hysterectomy (aOR 4.60 95% CI (1.02 to 20.7). The majority of hysterectomies (93.8%) were due to abnormal placentation.

CONCLUSION: An anterior placenta previa increases the risk of hysterectomy for both primary and repeat cesareans due to abnormal placentation. In the absence of accreta, blood transfusion remained a significant cause of maternal morbidity in both anterior and posterior placenta previas. This information may be useful for operative planning.