Risk factors for bladder injury during Cesarean Section are well known. Most of cases of bladder injury occur in presence of previous Cesarean Sections, morbidly adherent placenta, or previous bladder injury. limited evidence suggest that bladder filling may decrease the incidence of bladder injury. n our study, we compared the outcome of urinary bladder filling during Cesarean Section in cases at high risk of bladder injury.

In women at risk of bladder injury, such as in presence of previous Cesarean Section(s), there may tough adhesions between the bladder and the lower uterine segment. Trial of separation of the bladder in such circumstances may result in bladder injury. Filling of the bladder will delineate the contour of the bladder and clarify the proper plane of dissection. In a recent randomized clinical trial lower bladder filling resulted in non-significant decrease in the rate of bladder injury in women with placenta percreta. In our study, we compared the outcome of urinary bladder filling during Cesarean Section in cases at high risk of bladder injury.

Patients and Methods Inclusion criteria: Pregnant women at gestation from 20- 41 weeks who have any of the following risk factors

1. Previous Cesarean Section 3 times or more
2. Previous history of bladder injury during Cesarean Section
3. Operative report of extensive adhesions in the last Cesarean Section
4. Cesarean Section for placenta accreta spectrum Methods This is a randomized controlled trial done at the department of Obstetrics & Gynaecology unit, South Valley University from August 1st, 2017until the 30th of August 2018. The research is approved by the Committee of Ethics for Biomedical Researches, South Valley University at June 2017. All cases have informed consent before inclusion in the research. Closed envelop is used to randomized patients to either group. Group A: are cases of Cesarean section who have the intervention. Group: are cases of Cesarean section who do not have the intervention.

The intervention:

Triple-way urethral catheter insertion before establishment of anaesthesia. Evaluation of the drained urine is done (including: amount, character, and simple for culture and sensitivity). Instillation of 200 ml sterile saline is done by 50 ml syringe through the irrigation way. The irrigation way is closed temporarily by artery forceps. After laparotomy the bladder may be deflated by 50 ml or further inflated by 50 ml if needed to allow comfortable dissection. All Cesarean sections in both groups are done by the same surgeon supported by the same team in the same hospital. The Cesarean sections are done under spinal or general anaesthesia through pfannenstiel's incision. The catheter is removed 12 hours after Cesarean section. Postoperative follow up is maintained until 3 months from the time of the Cesarean section.

Inclusion Criteria:

• Previous Cesarean Section 3 times or more
• Previous history of bladder injury during Cesarean Section
• Operative report of extensive adhesions in the last Cesarean Section
• Cesarean Section for placenta accreta spectrum

Exclusion Criteria:

-

women undergoing Cesarean Section

IPD will be shared in unanonomous manner with the predetermined group of researchers

throughout the period of research until end of the study

IPD will be shared with the predetermined group of researchers as accepted by the local ethical and research committee.

closed envelop will be used for randomization. The patient and the investigator will be blinded.