26: Quantifying maternal morbidity associated with placenta previa


      Placenta previa is increasing, occurring in 1.3% of pregnancies, and is associated with maternal morbidity. Although the literature has focused on the morbidity associated with concurrent placenta accreta, the morbidity of previa in the absence of accreta with contemporary management is not well described. Hence, our purpose was to characterize maternal morbidity associated with placenta previa.

      Study Design

      Secondary analysis of the Maternal-Fetal Medicine Units Network Cesarean Registry including women undergoing cesarean delivery. Cohorts were those with previa compared to those without previa. Women with placenta accreta were excluded. Maternal hemorrhagic morbidity included mortality, blood product transfusion, atony requiring uterotonics, uterine/hypogastric artery ligation, hysterectomy, coagulopathy, exploratory laparotomy, and ICU admission. Severe maternal morbidity was defined as ICU admission or receipt of ≥4 units of blood products. Cohorts were compared using Wilcoxon rank sum test, chi-square test, and risk ratios (RRs). RRs were adjusted with poisson multivariable regression determined by backwards-stepwise elimination.


      501 women with previa were compared to 53,957 women without. Maternal hemorrhagic morbidity was higher with previa (19 vs 5%; aRR 2.9, 95% CI 2.2-3.9) (Table 1). Severe maternal morbidity was increased with previa (3 vs 1%) in univariate but not multivariable analysis. Women with previa had increased use of uterotonics (11 vs 4%, aRR 3.6), red blood cell transfusion (13 vs 2%, aRR 4.0), and hysterectomy (2 vs 0.2%, aRR 4.9). Women with previa also had a larger hemoglobin drop (2.3 g/dL vs 1.7 g/dL, p<0.001) and higher rate of ≥4 units red cells transfused (2.2 vs 0.6%, aRR 2.9 [1.1-8.0]). More women with previa had emergent delivery (24 vs 13%) but this did not persist after adjustment, aRR 1.2 (0.9-1.5).


      Almost 20% of women with previa but no accreta had hemorrhagic morbidity. 3% had severe morbidity and 2% required hysterectomy. These data are useful in counseling women with placenta previa.
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