Slow progress in labour and augmentation

She has been 6 cm for four hours. The midwife wants a decision, the consultant is in theatre, and the woman has been awake for thirty hours. Reach for syntocinon and you will be right most of the time — and catastrophically wrong occasionally.^[5][20]

The examinable skill here is not prescribing oxytocin. It is proving to yourself, in five minutes, that this is a power problem and not a passenger or passage problem.^[4][19]

Overview and definition

The ANZ definition, verbatim. RANZCOG C-Obs 31 defines slow labour by consensus as less than a 2 cm increase in cervical dilatation in a 4-hour period from 5 cm dilatation, adding that other features of the examination — descent, rotation and application of the head — may inform the diagnosis.^[4][2]

Two things follow from that sentence and both are examinable. The threshold starts at 5 cm, not at 4 cm, because the active phase starts at 5 cm. And dilatation is not the only variable: a cervix that has not moved while the head has descended and rotated is a different clinical animal.^[2][4]

Induced labour is not spontaneous labour. An induced latent phase is genuinely long, and applying spontaneous-labour thresholds to a woman who started at Bishop 3 manufactures a diagnosis of failure. Say which clock you are using.^[1][19]

References20ShowHide

1. [1]Zhang J, Landy HJ, Ware Branch D, et al. Contemporary patterns of spontaneous labor with normal neonatal outcomes Obstet Gynecol, 2010.PMID 21099592
2. [2]Oladapo OT, Diaz V, Bonet M, et al. Cervical dilatation patterns of 'low-risk' women with spontaneous labour and normal perinatal outcomes: a systematic review BJOG, 2018.PMID 28892266
3. [3]Abalos E, Oladapo OT, Chamillard M, et al. Duration of spontaneous labour in 'low-risk' women with 'normal' perinatal outcomes: A systematic review Eur J Obstet Gynecol Reprod Biol, 2018.PMID 29518643
4. [4]Abalos E, Chamillard M, Díaz V, et al. Progression of the first stage of spontaneous labour Best Pract Res Clin Obstet Gynaecol, 2020.PMID 32247770
5. [5]Bugg GJ, Siddiqui F, Thornton JG Oxytocin versus no treatment or delayed treatment for slow progress in the first stage of spontaneous labour Cochrane Database Syst Rev, 2013.PMID 23794255
6. [6]Kenyon S, Tokumasu H, Dowswell T, et al. High-dose versus low-dose oxytocin for augmentation of delayed labour Cochrane Database Syst Rev, 2013.PMID 23853046
7. [7]Wei S, Wo BL, Qi HP, et al. Early amniotomy and early oxytocin for prevention of, or therapy for, delay in first stage spontaneous labour compared with routine care Cochrane Database Syst Rev, 2013.PMID 23926074
8. [8]Smyth RM, Markham C, Dowswell T Amniotomy for shortening spontaneous labour Cochrane Database Syst Rev, 2013.PMID 23780653
9. [9]Rouse DJ, Weiner SJ, Bloom SL, et al. Second-stage labor duration in nulliparous women: relationship to maternal and perinatal outcomes Am J Obstet Gynecol, 2009.PMID 19788967
10. [10]Laughon SK, Berghella V, Reddy UM, et al. Neonatal and maternal outcomes with prolonged second stage of labor Obstet Gynecol, 2014.PMID 24901265
11. [11]Gimovsky AC, Berghella V Randomized controlled trial of prolonged second stage: extending the time limit vs usual guidelines Am J Obstet Gynecol, 2016.PMID 26928148
12. [12]Cahill AG, Srinivas SK, Tita ATN, et al. Effect of Immediate vs Delayed Pushing on Rates of Spontaneous Vaginal Delivery Among Nulliparous Women Receiving Neuraxial Analgesia: A Randomized Clinical Trial JAMA, 2018.PMID 30304425
13. [13]Phipps H, Osborn DA, Zhang R, et al. Prophylactic manual rotation of the fetal head (manual rotation alone) to reduce operative delivery and complications for mother and babies Cochrane Database Syst Rev, 2025.PMID 40678975
14. [14]Lawrence A, Lewis L, Hofmeyr GJ, et al. Maternal positions and mobility during first stage labour Cochrane Database Syst Rev, 2013.PMID 24105444
15. [15]Lavender T, Cuthbert A, Smyth RM Effect of partograph use on outcomes for women in spontaneous labour at term and their babies Cochrane Database Syst Rev, 2018.PMID 30080256
16. [16]Ubom AE, Nieto-Calvache AJ, Malel ZJ, et al. FIGO position statement on the use of the WHO labor care guide versus the partograph Int J Gynaecol Obstet, 2025.PMID 40285693
17. [17]Bohren MA, Hofmeyr GJ, Sakala C, et al. Continuous support for women during childbirth Cochrane Database Syst Rev, 2017.PMID 28681500
18. [18]Boie S, Glavind J, Velu AV, et al. Discontinuation of intravenous oxytocin in the active phase of induced labour Cochrane Database Syst Rev, 2018.PMID 30125998
19. [19]American College of Obstetricians and Gynecologists Quality-Improvement Strategies for Safe Reduction of Primary Cesarean Birth: ACOG Committee Statement No. 17 Obstet Gynecol, 2025.PMID 40245424
20. [20]Leathersich SJ, Vogel JP, Tran TS, et al. Acute tocolysis for uterine tachysystole or suspected fetal distress Cochrane Database Syst Rev, 2018.PMID 29971813