Risk factors and pregnancy outcome in different types of placenta previa.

Objective: To compare risk factors and pregnancy outcome between different types of placenta previa (PP).

Materials And Methods: We conducted a retrospective study of 306 women presenting with PP over a 10-year period from January 1996 to December 2005. Differences between women with major and minor PP regarding age, parity, history of Caesarean section, antepartum hemorrhage, preterm deliveries, placenta accreta, Caesarean hysterectomy, operative complications, and neonatal outcome were identified using Mann-Whitney U test, chi-square test, and multivariate logistic regression.

Results: The overall incidence of PP was 0.73%. Major PP (complete or partial PP) occurred in 173 women (56.5%) and minor PP (marginal PP or low-lying placenta) in 133 women (43.5%). There were no differences between women with major and minor PP regarding age, parity, and previous miscarriages. After controlling for confounding factors, women with major PP showed a significantly higher incidence of antepartum hemorrhage (OR 3.18; 95% CI 1.58-6.4, P = 0.001), placenta accreta (OR 3.2; 95% CI 1.22-8.33, P = 0.017), and hysterectomy (OR 5.1; 95% CI 1.31-19.86, P = 0.019). Antepartum hemorrhage in women with PP was associated with premature delivery (OR 14.9; 95% CI 4.9-45.1, P < 0.001), more commonly in women with major PP. The only significant difference between women with major and minor PP regarding neonatal outcome was that major PP was associated with a higher incidence of admission to the neonatal intensive care unit (P = 0.014).

Conclusion: Complete or partial placenta previa is associated with higher morbidity than marginal placenta previa or low-lying placenta.