Cervical Ripening, Induction of Labor
Conditions
Keywords
cervical foley catheter
Brief summary
This study aims to determine what type of traction, weighted bag or inner thigh taping, on foley catheters for cervical ripening results in a greater cervical dilation and shorter length of labor. The primary outcomes are post-ripening dilation of 3 cm or more and time to delivery. The secondary outcomes are patient pain/comfort rating and method of delivery. The investigators hypothesize that the use a weighted bag will result in a 20% increase in post-ripening dilation of at least 3 cm and a shorter average length of labor.
Detailed description
Over the last 20 years the number of induced labors doubled so that over one in five births in 2003 was induced. In response to the rising need for cervical ripening the American College Obstetricians and Gynecologists have stated that both mechanical and prostaglandin ripening is acceptable and safe. Prior to beginning an induction, the Bishop score (cervical dilation, effacement, station, consistency, and position) is assessed. With Bishop scores less than five, a cervical ripening agent is commonly used. The mechanical dilation with a foley catheter works by both a direct stretching of the lower uterine segment and cervix and a local inflammatory response that releases matrix metalloproteinases and prostaglandins. It is often chosen due to its lower cost, low incidence of systemic side effects, and low risk of hyperstimulation. Compared to misoprostol a foley with oxytocin was more effective at induction in primiparous patients, more effective at improving the dilation, safe to use after misoprostol, and not associated with an increased risk of uterine rupture in a vaginal birth after cesarean (VBAC). The foley was also shown to have a shorter induction time and less contractile abnormalities than prostaglandin E2 gel and no increased rate of uterine rupture in VBAC attempts. The use of extra-amniotic saline infusion with a foley catheter has been used to augment the mechanical stretching, however this did not decrease the induction time or improve the outcomes. Finally, a Cochrane Database review found that mechanical methods of cervical ripening were equally effective as prostaglandin agents. Although the safety, efficacy, and side effects of foley catheter ripening have been compared with multiple other methods for cervical ripening, very few studies have compared different protocols for foley placement. One study showed that the use of oxytocin while the foley catheter was in place did not significantly shorten the time to delivery. Levy et al showed that a larger, 80 ml, balloon resulted in a greater post-ripening dilation and a higher number of deliveries in 24hours. No study to date has examined how the traction placed on the foley catheter affects the outcome. Therefore, we propose doing a randomized controlled study in which the control is the current standard of care at MetroHealth Medical Center of placing a 500cc weight on the foley and placing it to gravity over the end of the bed. The comparison will be the method used at many institutions where the foley catheter is placed on gentle traction and taped to the inner thigh of the patient. The primary outcomes measured will be a post-ripening dilation of 3cm or more and time to delivery. The secondary outcomes are patient pain/comfort rating and method of delivery.
Interventions
OTHERweighted bag
For the weighted bag, a 500cc saline bag will be taped to an empty Foley bag which will be attached to the cervical Foley catheter. This bag will then be placed to gravity over the end of the bed. The bed will be raised so that the bag does not touch the floor. The foley and the bag will be re-assessed every 30min by the nursing staff.
OTHERleg taping
For the leg taping, the cervical foley catheter will be pulled to gentle traction and attached to the patient's inner thigh using a reclosable foley catheter fastener. The foley catheter and the traction will be assessed every 30min by the nursing staff. The tension will be renewed and the Foley re-adjusted if necessary at each check.
Sponsors
MetroHealth Medical Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Single viable intrauterine pregnancy * Cephalic presentation * Bishop score \<6 * Need for induction of labor
Exclusion criteria
* Multiple gestation * Bishop score \>6 * Spontaneous labor/regular contractions on admission * Rupture of membranes * Previous uterine scar * Grandmultiparity (greater than 5 deliveries)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Time to Delivery | an average of 20 hours, up to 40 hours |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Patient Pain/Comfort Rating | an average of 20 hours, up to 40 hours | Using a visual analog pain scale, with 0 being no pain and 10 being the most severe pain possible, the patients were asked to assess their pain every hour. The highest pain score recorded while the Foley catheter was in place was used. The data are reported as the median and range. |
| Time to Foley Expulsion | an average of 2 hours, up to 12 hours | time from Foley placement until it is spontaneously expulsed from the cervix |
Other
| Measure | Time frame | Description |
|---|---|---|
| Maternal Morbidities | 30 days after delivery | post-partum hemorrhage, clinical chorionamnionitis, endomyometritis, cervical laceration, second procedure, readmission, DVT |
Countries
United States
Participant flow
Recruitment details
We performed a single-site randomized controlled trial at MetroHealth Medical Center, a tertiary hospital, from December 2009 to July 2012.
Pre-assignment details
Eligibility criteria included: admission for an induction of labor, a fetus in cephalic presentation, and an unripe cervix defined as a Bishop score ≤ 6.
Participants by arm
| Arm | Count |
|---|---|
| Weighted Bag (Traction) For the weighted bag, a 500cc saline bag will be taped to an empty Foley bag which will be attached to the cervical Foley catheter. This bag will then be placed to gravity over the end of the bed. The bed will be raised so that the bag does not touch the floor. The foley and the bag will be re-assessed every 30min by the nursing staff. | 99 |
| Leg Taping (Taping) For the leg taping, the cervical foley catheter will be pulled to gentle traction and attached to the patient's inner thigh using a reclosable foley catheter fastener. The foley catheter and the traction will be assessed every 30min by the nursing staff. The tension will be renewed and the Foley re-adjusted if necessary at each check. | 98 |
| Total | 197 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | ineligible for study | 2 | 2 |
| Overall Study | Physician Decision | 1 | 1 |
Baseline characteristics
| Characteristic | Leg Taping (Taping) | Weighted Bag (Traction) | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 2 Participants | 2 Participants | 4 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 96 Participants | 97 Participants | 193 Participants |
| Age Continuous | 25.5 years STANDARD_DEVIATION 5.9 | 25.7 years STANDARD_DEVIATION 6.9 | 25.6 years STANDARD_DEVIATION 6.4 |
| Region of Enrollment United States | 98 participants | 99 participants | 197 participants |
| Sex: Female, Male Female | 98 Participants | 99 Participants | 197 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 96 | 0 / 95 |
| serious Total, serious adverse events | 0 / 96 | 0 / 95 |
Outcome results
Primary
Time to Delivery
Time frame: an average of 20 hours, up to 40 hours
Population: In order to find a 20% difference with a 40% standard deviation, power of 90%, and alpha of 0.05, we estimated we needed 86 patients in each arm. We aimed to recruit 194 patients to account for potential dropouts and missing data.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Weighted Bag (Traction) | Time to Delivery | 19.8 hours | Standard Deviation 8.5 |
| Leg Taping (Taping) | Time to Delivery | 18.8 hours | Standard Deviation 8 |
Secondary
Patient Pain/Comfort Rating
Using a visual analog pain scale, with 0 being no pain and 10 being the most severe pain possible, the patients were asked to assess their pain every hour. The highest pain score recorded while the Foley catheter was in place was used. The data are reported as the median and range.
Time frame: an average of 20 hours, up to 40 hours
Population: All patients had pain scores recorded and used in analysis. The values in the table represented the recorded data available and used in the analysis.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Weighted Bag (Traction) | Patient Pain/Comfort Rating | 5 units on a scale |
| Leg Taping (Taping) | Patient Pain/Comfort Rating | 5 units on a scale |
Secondary
Time to Foley Expulsion
time from Foley placement until it is spontaneously expulsed from the cervix
Time frame: an average of 2 hours, up to 12 hours
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Weighted Bag (Traction) | Time to Foley Expulsion | 1.5 hours |
| Leg Taping (Taping) | Time to Foley Expulsion | 2.6 hours |
Other Pre-specified
Maternal Morbidities
post-partum hemorrhage, clinical chorionamnionitis, endomyometritis, cervical laceration, second procedure, readmission, DVT
Time frame: 30 days after delivery
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Weighted Bag (Traction) | Maternal Morbidities | 17 diagnoses |
| Leg Taping (Taping) | Maternal Morbidities | 16 diagnoses |