///2019 Abstract Details
2019 Abstract Details2019-07-13T07:45:15-05:00

Effect of Labor Stage Duration on Delivery Mode: A Retrospective Cohort Study After the 2014 ACOG Labor Management Consensus

Abstract Number: F3D-531
Abstract Type: Original Research

Jie Zhou MD, MS, MBA, FASA1 ; Li Wang MD2; Qing Liu MD3; Wenjie Qing MD4; Min Wei MD5


In 2014, American College of Obstetricians and Gynecologists (ACOG) published a new labor management consensus with the intention to prevent the primary Cesarean Delivery (CD). It was proposed that the rate of CD could be lowered by additional allowance of first and second stages of labor trial. However, recent reports showed no reduction in CD rate, but increased maternal and perinatal morbidity with the practice of the new guideline. We examined the duration of labor in relation to the delivery modes.


Retrospective chart review of parturients delivered from 1/1/2017 to 12/31/2017 at the Brigham and Women’s Hospital were collected. Paturients with elective CDs, VBACs, multiple gestations, and missing records of either stage of labor were excluded. The lengths of 1st, 2nd and total (1st + 2nd) labor stages duration were compared among different modes of delivery. Subgroup analysis was conducted according to nulliparous vs multiparous status with or without labor analgesia.


Of 1721 parturients who were included, 864 were nulliparous and 857 were multiparous. Table 1 showed that the 1st stage, 2nd stage and total labor duration operative vaginal deliveries (OVDs) were longer than that of spontaneous vaginal deliveries (SVDs), but shorter than intrapartum cesarean deliveries (ICD), regardless the nulliparous (with or without labor analgesia) or multiparous status. The increase of the 2nd stage duration was significantly correlated with increased OVD and ICD. (Figure 1)


The new ACOG guideline made two major modifications to the previous works of Friedman: active labor begins at 6 cm of cervical dilation; allowance of at least 1-hour additional to the 2nd stage of parturients (may allow more with epidural analgesia). Such practice recommendation has been criticized for lack of evidence. Our study demonstrated that OVDs and ICDs rates had already increased before reaching the 2014 guideline allow maximum hours. This indicated that extra time allowance probably is not helpful for reducing CD rate. Our study further demonstrated that the long the 2nd stage labor, the greater the risk of OVD and ICD. We advocate for large prospective study to further stratified the length limits of labor stages.


1. https://www.acog.org/Clinical-Guidance-and-Publications/Obstetric-Care-Consensus-Series

2. Rosenbloom, JI, et al. Am J Obstet Gynecol 2017; 217: 689

3. Cohen, SM, et al. Ultrasound Obstet Gynecol 2017; 50: 423

SOAP 2019