The bladder flap at the time of cesarean delivery is the term used to describe the separation of the bladder from the lower uterine segment by sharply incising the vesico-uterine peritoneum or serosa and using blunt and/or sharp dissection to develop this potential space which facilitates placement of a retractor, known as the bladder blade. Creating a bladder flap at the time of cesarean delivery is largely based on individual practice patterns and practitioners are divided in their use of this step. While creating a bladder flap has a theoretical advantage of protecting the bladder from injury, it is unknown whether this step has an effect on postoperative bladder function. The purpose of this study was to evaluate whether the omission or creation of a bladder flap results in a change in urinary symptoms as measured by the UDI-6 component of the PFDI-20.

This is a Parallel Assignment design study. The PFDI-20 symptom questionnaire was completed upon enrollment. After the patient was prepped and draped, the operating room nurse opened a sealed opaque envelope marked with the study subject number containing a card marked with the assignment to bladder flap or no bladder flap, which was shown to the surgeons prior to the skin incision. The patient did not see the allocation nor was it verbalized in the operating room. The PFDI-20 was repeated 6-8 weeks after delivery at the patient's postpartum exam clinic visit. Equal number of bladder flap and no bladder flap assignment cards were randomly shuffled and placed in envelopes marked with the study subject ID number prior to the start of the study.

The study hypothesis was that the omission of the bladder flap at the time of primary cesarean delivery would be associated with lower urinary symptoms scores in the postpartum as measured by the UDI-6 component of the PFDI-20.

Inclusion Criteria:

• pregnant at 37 weeks gestation or greater
• scheduled for a non-urgent primary cesarean delivery

Exclusion Criteria:

• pre-term (defined as less than 37 weeks 0 days gestation) prior pelvic surgery involving the bladder
• a diagnosis of any of the following conditions: endometriosis, uterine leiomyomata, chronic pelvic pain, urinary incontinence prior to pregnancy, nephrolithiasis during the current pregnancy,
• any circumstance that precluded adequate informed consent at the time of recruitment (such as a need to for urgent or emergent delivery)
• if the indication for cesarean was a failed trial of operative vaginal delivery (forceps or vacuum extraction)