INTRODUCTION

Placenta previa is generally defined as the implantation of the placenta over or near the internal os of the cervix. There are four types of placenta previa; total, low-lying, partial, and marginal. The higher incidence of low-lying placenta and placenta previa is sonographically diagnosed in the second trimester and ranges from 6% to 46%. This rate, however, decreases to as low as 0.5 % at delivery (11). Despite advances in blood transfusion techniques and surgical procedures, abnormal placentation still remains a difficult challenge for obstetricians. Intrapartum maternal hemorrhage and the need for emergency cesarean section or hysterectomy related to abnormal placentation are main causes of maternal-fetal morbidity and mortality.

The overall incidence of placenta previa at delivery is reported as 0.5 % in most studies (3, 5) and the risk factors for placenta previa include advanced maternal age (above 35 years), parity, smoking, and, most importantly, prior cesarean delivery. Placenta previa with prior cesarean delivery increases risk up to 1% - 4%. As the number of previous cesarean deliveries increases, the incidence of placenta previa and abnormal placentation shows a linear increase (3). Vaginal ultrasound is the most accurate method for localizing and diagnosing placenta previa, because it can provide a better resolution in the lower margin of the placenta (4, 6, 11). There is a little increase in congenital anomalies associated with placenta previa when compared to normal pregnancies, but this increase could be attributable to advanced maternal age (2).

In current practice, patients with placenta previa usually present with two clinical forms. The first clinical form is massive life threatening vaginal bleeding for which patients with placenta previa most often require emergency surgical interventions and immediate delivery.
Whether diagnosed before or not, these patients have many more intraoperative risks than patients with placenta previa who are delivered electively. In the second clinical form, patients with placenta previa are diagnosed prenatally or with a second trimester vaginal bleeding for which conservative management is successful. These patients are usually delivered by physicians at the time when the fetal lung maturity becomes suitable for delivery or when obstetric indications require delivery.

CONCLUSION

Placenta previa usually presents with life-threatening vaginal bleeding and requires immediate cesarean section and delivery. In these cases, multiple transfusions and proper surgical interventions may reduce maternal mortality and morbidity. Surgeon’s skills and logical protocols developed for the management of this condition are important in reducing mortality and complications, but in this study all surgical interventions were performed by our department surgeons. Emergency cesarean section has more complication rate and maternal morbidity rates than that in the elective cesarean section in older studies (8, 10). In modern obstetrics, the knowledge from older studies could not be applied to current practice. Advances in blood transfusions and surgical techniques may prevent maternal deaths and complications due to placenta previa. In this study there was no increase in maternal morbidity and complications. However, the number of the patients in our study is very low and further studies with large series are needed to prove this issue.

Current treatment for these patients is close observation and proper blood transfusions. If delivery is inevitable, the risk of placenta accreta and the necessity of hysterectomy should be considered and immediate surgical preparation and blood transfusion should be taken to reduce the risk of maternal morbidity. In this study, there was no statistically significant difference between the two groups regarding the amount of blood transfusion. In the emergency cesarean section group which required obstetric hysterectomy for placentation abnormalities, the blood transfusion amount was significantly higher. An unexpected massive bleeding from abnormal placentation during operation can cause fear and decreased judgment Ncapability, even in experienced hands. The most recent studies revealed that placenta previa and abnormal placentation are the most common indications for obstetric hysterectomies (1,9). Accordingly, during this period (between the years 2000 and 2004; our unpublished data) placentation abnormality due to accreta was the most common cause for obstetric hysterectomy. Emergency cesarean section has more complication rates when compared with elective cesarean section such as bladder injuries, bowel lacerations, pelvic hematomas and wound infections. In this study, we had two wound infections in both groups and one bladder injury and reparation due to placenta percreta in the elective cesarean section group. In this study, comparison of complications between the two groups showed no statistically significant difference.

Most data obtained from literature showed that perinatal outcome for patients with placenta previa does not differ from those of normal pregnancies (7, 8) Prematurity is the most common reason for fetal morbidity and mortality. In our study, data obtained from the patients was identical to this, although in our series two babies died from severe anemia due to fetal hemorrhage during delivery. Although we did not further subdivide groups according to localization of placentas, anterior localization of placenta previa may especially prolong the time to deliver the baby during the operation. When the placenta is in anterior location, the surgeon generally has to incise the placenta which could cause fetal hemorrhage. It is important to emphasize that a neonatal team must be also ready for neonatal resuscitation and blood transfusion in case of unexpected fetal hemorrhage.

Based on the results of this study, we can conclude that emergency cesarean section due to placenta previa does not increase maternal mortality and morbidity in the presence of modern blood transfusion techniques and surgical improvements. There is a significant increase in blood transfusion amount and the operation time among the patients managed with emergency cesarean section due to placenta previa. It is also important to remember that anterior localization of placenta previa is a special condition that the surgeon could incise the placenta during cesarean section and fetal hemorrhage could occur. The neonatal team has to be ready for this condition.