Mouth Guard Use in the Second Stage of Labor
Mouth Guard Use in the Second Stage of Labor
Shortening the second stage of labor, the time spent pushing the baby out, is important for
 positive mother and infant's outcomes. Lack of progress of labor for any reason is the most
 common reason for cesarean section in women having their first baby and the second most
 common reason for cesarean section in women who have already had a baby. In 2014, a large
 study done across the United States showed increases in complications in both mother and
 infant when pushing was prolonged, including uterine infection, postpartum hemorrhage, more
 extensive vaginal tearing, shoulder dystocia, 5 minute Apgar score less than 4, infant
 admission to Neonatal Intensive Care Unit and neonatal infections. Therefore, the challenge
 is to consider alternative practices in order to maximize a mother's chance of a vaginal
 delivery and minimize these associated risks to both mother and baby.

 Mouth guards are used primarily in contact sports, and have been demonstrated to reduce or
 prevent injury to the teeth. Additionally, it has been proposed that wearing a mouth guard
 increases the strength of different muscle groups. A recent randomized controlled pilot study
 including women with their first pregnancy using a dental support device (DSD) during the
 second stage of labor evaluated the length of the second stage and outcomes. They found a
 significant decrease of 38% in the length of pushing time in the group that used a DSD.
 Additionally, there was a decreased rate of cesarean section in this group, however a p-value
 was not reported. This study only included 64 patients. A second, larger trial did not find a
 significant difference in pushing time, however the rate of interventions such as a vacuum or
 forceps-assisted vaginal delivery and cesarean section were much higher in the control group
 due to prolonged pushing. The results of the second study are contradictory in nature, yet
 the researchers do not provide hypotheses into why this may be.

 It is clear from the previously mentioned studies that further research is needed. Our
 hypothesis is that using such a device would help women to push more effectively during the
 second stage of labor thus shortening the time needed to push the baby out and increasing the
 rate of vaginal delivery. The purpose of this study is to determine whether wearing a mouth
 guard in the second stage of labor affects the length of the second stage of labor and
 improves mother & infant outcomes.
Optimizing the second stage of labor is important for positive maternal and neonatal
 outcomes. Dystocia of labor refers to a lack of progress of labor for any reason, and it is
 the most common indication for cesarean delivery in nulliparous women and the second most
 common indication for cesarean delivery in multiparous women. In 2014, a large US multicenter
 cohort study showed increases in maternal and neonatal morbidities when the second stage was
 prolonged, including chorioamnionitis, postpartum hemorrhage, 3rd and 4th degree perineal
 laceration, shoulder dystocia, 5 minute Apgar score less than 4, neonatal admission to NICU
 and neonatal sepsis. Therefore, clinicians are challenged to consider alternative practices
 in order to maximize a mother's chance of a normal delivery and minimize these associated
 risks to both mother and baby.

 Mouth guards are used primarily in contact sports, and have been demonstrated to reduce or
 prevent injury to the teeth. Most commonly made of synthetic polymers, mouth guards function
 as a shock-absorber. Even among sports medicine literature, there is a call for more research
 into use and education about protective gear. Previous studies have shown that wearing a
 mouth guard increases the isometric strength of different muscle groups. Recent studies have
 begun to explore whether wearing a similar style mouth guard will shorten the duration of the
 second stage of labor. A recent randomized controlled pilot study including nulliparous women
 using a dental support device (DSD) during the second stage evaluated the length of the
 second stage and outcome thereof. They defined the second stage of labor as the time between
 complete cervical dilation and fetal expulsion. They found a significant decrease of 38% in
 the length of the second stage in the group that used a DSD. Additionally, there was a
 decreased rate of cesarean section in this group, however a p-value was not reported. This
 study only included 64 patients. A second, larger trial also looking at nulliparous women did
 not find a significant difference in length of second stage of labor however the rate of
 obstetrical interventions such as operative vaginal delivery and cesarean section were much
 higher in the control group due to prolonged second stage of labor. Though the results of the
 second study are contradictory in nature, the researchers do not provide hypotheses into why
 this may be.

 Our hypothesis is that using such a device would help women to push more effectively during
 the second stage of labor thus shortening the second stage and increasing the rate of
 spontaneous vaginal deliveries that do not require operative intervention. Developing a way
 to shorten the second stage of labor and reduce the number of cesarean sections or
 instrumental deliveries could reduce the morbidity of mothers and their infants and decrease
 health care spending.
Inclusion Criteria:

 -  Nulliparous women

 -  Age 18-55

 -  Presenting for delivery at Christiana Care Health Services

 -  Singleton pregnancy

 -  Cephalic pregnancy

 -  Term pregnancy

 Exclusion Criteria:

 -  Multiple gestation

 -  Known uterine anomalies, excluding resected uterine septums and fibroids

 -  Estimated fetal weight less than 10th% for gestation age with abnormal umbilical
 dopplers

 -  Estimated fetal weight less than the 5th percentile

 -  History of cardiac disease requiring assisted second stage of labor

 -  Oral implants, braces or active dental infection precluding mouth guard use

 -  Preeclampsia with severe features treated with magnesium sulfate

 -  History of shoulder dystocia

 -  History of myomectomy

 -  Maternal history of myasthenia gravis

 -  Maternal history of sleep apnea with home CPAP use

 -  Category III fetal heart tracing

 -  Active vaginal bleeding consistent with placental abruption

 -  Diagnosis of chorioamnionitis prior to start of second stage of labor

 -  Participation in another interventional research study