Risk of adverse maternal and peri-natal outcome in subjects with placenta previa with previous cesarean section

Associated factors of blood transfusion for Caesarean sections in pure placenta praevia pregnancies

INTRODUCTION

This study aimed to evaluate associated factors of blood transfusion for Caesarean sections in pure placenta praevia pregnancies.

METHODS

A case-control study was conducted among 405 pregnant women with placenta praevia who underwent Caesarean delivery between August 2004 and December 2013. 135 of the women received blood transfusions. Another 270 women who did not receive any blood transfusion were randomly selected and served as controls. Maternal demographic data, reproductive history, antepartum profiles and obstetric outcomes were compared between the two groups.

RESULTS

Women in the case group were significantly more likely to be multiparous, deliver at a gestational age of less than 37 weeks, have a prior Caesarean delivery, experience preoperative bleeding and anaemia, and have major and anterior placenta praevia (p < 0.05). Multivariate analysis demonstrated that significant, independently associated factors of blood transfusion were: previous Caesarean section (adjusted odds ratio [OR] 2.30, 95% confidence interval [CI] 1.36-3.90), anterior placenta praevia (adjusted OR 2.30, 95% CI 1.15-4.60), major placenta praevia (adjusted OR 2.39, 95% CI 1.34-4.22), preoperative bleeding of more than 250 mL (adjusted OR 6.11, 95% CI 2.35-15.90), preoperative anaemia (adjusted OR 2.31, 95% CI 1.34-4.00) and emergency Caesarean section (adjusted OR 2.14, 95% CI 1.08-4.22).

CONCLUSION

Previous Caesarean section, anterior placentation, major placenta praevia, preoperative bleeding of more than 250 mL, preoperative anaemia and emergency Caesarean section were independent factors that increased the risk of blood transfusion for Caesarean section in pure placenta praevia pregnancies.

Effect of site of placentation on pregnancy outcomes in patients with placenta previa

INTRODUCTION

We aimed to evaluate the site of placentation on the pregnancy outcomes of patients with placenta previa.

METHODS

This retrospective study included 678 cases of placenta previa. Basic information and pregnancy outcome data were collected. Differences between the different placenta previa positions and pregnancy outcomes were compared using the chi-square and independent t tests. Logistic and multiple regression analyses were used to calculate the odds ratios (ORs) to determine the risk factors for PAS disorders and postpartum hemorrhage and evaluate the effect of placental attachment site on pregnancy outcomes.

RESULTS

There was no significant difference between the PAS disorders rate and the incidence of complete placenta previa depending on the type of placentation; however, placental attachment site influenced the pregnancy outcome. Placental attachment to the anterior wall was associated with shorter gestational age, low birth weight, lower Apgar score, higher prenatal bleeding rate, increased postpartum hemorrhage, longer duration of hospitalization, and higher blood transfusion and hysterectomy rates compared to cases with lateral/posterior wall placenta. Placental attachment at the incision site of a previous cesarean section significantly increased the incidence of complete placenta previa and PAS disorders compared with placental attachment at a site without incision, but did not significantly influence pregnancy outcomes. Placental attachment to the anterior wall was an independent risk factor for postpartum hemorrhage in patients with placenta previa. Placental attachment to a previous incision site was an independent risk factor for PAS disorders.

CONCLUSION

The site of placental attachment in patients with placenta previa has an important influence on the pregnancy outcome. When the placenta is located on the anterior wall, clinicians should pay attention to the adverse pregnancy outcomes and the possibility of massive postpartum hemorrhage. In cases of placental attachment to the uterine incision site, physicians should be highly vigilant regarding the occurrence of PAS disorders.