A 2010 journal article by Zhang, et al for the Consortium on Safe Labor, titled Contemporary Cesarean Delivery Practice in the US, and a 2014 consensus statement from ACOG and Society for Maternal Fetal Medicine argue for a re-definition of what should be considered prolonged labor, and when intervention should happen.Here is a brief summary:
|Phase||Definition||Friedman / standard practice||Consortium on Safe Labor / ACOG & SMFM|
|Latent||When mother perceives regular contractions||Prolonged if over 20 hr in nullips, and 14 in multips||A prolonged latent phase (e.g. over 20 hours) is not an indication for cesarean. If it is not treated, women may stop contracting or may eventually reach active labor. If treated with AROM and Pitocin, most will enter active labor.|
|Active||When rate of dilation significantly increases. Protracted = slow. Arrest = progress has stopped.||Protracted if < 1.2 cm/hr for nullips and < 1.5 for multips.||Typical dilation ranged from .5 cm/hr to .7 for nullips, and from .5 to 1.3 for multips. From 4-6 cm, dilation is slower than historically described. After 6 cm, progress speeds up. Protracted labor should not be diagnosed before 6 cm. After 6 cm, protracted labor is not an indication for cesarean as long as there is progress, even if it’s slow.|
|Arrest if no change in 2 hours (after 4 cm and with adequate contractions)||Cesarean for arrest should only be for women who are beyond 6 cm with ruptured membranes who fail to progress despite 4 hours of adequate uterine activity or, for those with inadequate contractions, at least 6 hours on Pitocin.|
|Second Stage||When cervix is fully dilated through delivery. (Note: some researchers argue we should define it as when the mother develops the urge to push)||Typical practice has been to limit nullips to three hours, and multips to two, even with epidural. (ACOG)||Parity, delayed pushing, use of epidural analgesia, mom’s BMI, birth weight, and OP position affect length of pushing. (e.g. pushing is one hour longer on average with epidural). No absolute maximum length of pushing has been defined. Arrest should not be diagnosed until after 3 hours pushing for a nullip, and 2 for multip – longer if she has an epidural or diagnosed malposition. In case of prolonged second stage or arrest of descent, vacuum, forceps, and manual rotation of the fetus should be considered prior to cesarean.|
In an induced labor, latent phase may go 24 hours or longer. It should not be considered a “failed induction” until Pitocin has been administered for at least 12 – 18 hours after AROM.