Management of Arrest in Cervical Dilation Secondary to Pelvic Inlet Contraction

Introduction to Cephalopelvic Disproportion

The American College of Obstetricians and Gynecologists recommends that cesarean delivery is the safest and most prudent option when arrest of cervical dilation occurs secondary to pelvic inlet contraction, as oxytocin augmentation is contraindicated and vaginal delivery should not be attempted 1, 2, 3

Cephalopelvic disproportion occurs in 40-50% of all active phase arrest cases, making it the most important factor to evaluate, according to the American College of Obstetricians and Gynecologists 1, 2
Clinical signs of cephalopelvic disproportion include increasingly marked molding, deflexion, asynclitism of the fetal head without descent, and failure of the fetal head to descend despite contractions, as stated by the American College of Obstetricians and Gynecologists 1, 4
Serial suprapubic palpation of the base of the fetal skull is essential to differentiate true descent from molding alone, as recommended by the American College of Obstetricians and Gynecologists 3, 5

The American College of Obstetricians and Gynecologists states that the risks of maternal and fetal damage are too great to attempt vaginal delivery when cephalopelvic disproportion is present or cannot be ruled out with reasonable certainty 2, 3, 5
The 2023 American College of Obstetricians and Gynecologists guidelines explicitly state that "it is better to err on the side of intervention by CD in the presence of uncertainty about potential harm than to allow labor in the false hope that safe vaginal delivery may occur" 1, 2
When cephalopelvic disproportion is confirmed with arrest disorder, the American College of Obstetricians and Gynecologists recommends that cesarean delivery is a more prudent and safer choice because vaginal delivery is "unlikely to be achievable, let alone safely" 3, 5

The American College of Obstetricians and Gynecologists recommends that if associated with evidence of cephalopelvic disproportion, ecbolic agents are best avoided, as attempting oxytocin augmentation in the presence of cephalopelvic disproportion risks uterine hyperstimulation without achieving vaginal delivery 6, 4
Oxytocin augmentation in the presence of cephalopelvic disproportion increases maternal trauma, such as uterine rupture risk and severe lacerations, and fetal trauma, such as excessive molding and potential asphyxia, according to the American College of Obstetricians and Gynecologists 1, 3

The American College of Obstetricians and Gynecologists notes that when cephalopelvic disproportion is present, additional risk factors that support cesarean decision include maternal diabetes and obesity 3, fetal macrosomia 4, malposition, such as occiput posterior or transverse 4, malpresentation, such as brow presentation 4, marked asynclitism 4, and excessive molding without descent 1

The American College of Obstetricians and Gynecologists recommends that astute clinicians will often recognize cephalopelvic disproportion and proceed to cesarean delivery before formal arrest criteria are met, especially when malposition or excessive molding is noted on examination 1, 2