BACKGROUND
Assessment of labor progress via digital examination is considered the standard of
care in most delivery rooms. However, this method can be stressful, painful, and imprecise,
and multiple examinations increase the risk for chorioamnionitis. Intrapartum ultrasound
was found to be an objective, noninvasive tool to monitor labor progression.
OBJECTIVE
This study aimed to investigate whether, among nulliparous women, the use of intrapartum
ultrasound can reduce the rate of intrapartum fever by reducing the number of digital
examinations.
STUDY DESIGN
This was a prospective, randomized controlled trial in term nulliparas admitted with
prelabor rupture of membranes, induction of labor, or in latent phase of labor with
a cervical dilation of <4 cm. Women were randomized into 1 of the following 2 arms:
(1) labor progress assessed by ultrasound, avoiding digital examinations as much as
possible; and (2) control group in which labor progression was assessed according
to the regular protocol. Before the study, all labor ward physicians underwent training
in intrapartum ultrasound.
RESULTS
A total of 90 women were randomized to the ultrasound group and 92 were randomized
to the control group. When compared with the control group, the ultrasound group had
significantly lower rates of intrapartum fever (11.1% vs 26.1%; P=.01), clinical chorioamnionitis (3.3% vs 16.5%; P>.01), and histologic chorioamnionitis (2.2% vs 9.8%; P=.03). The median number of digital examinations was significantly lower in the ultrasound
group (5; interquartile range, 4–6) than in the control group (8; interquartile range,
6–10; P<.01). The median number of digital examinations per hour in the ultrasound group
was significantly lower than in the control group (0.2 vs 0.4; P<.01). The induction rates, time from admission to delivery, mode of delivery, Apgar
score at 5 minutes, and neonatal intensive care unit admission rates did not differ
significantly between the groups.
CONCLUSION
The use of intrapartum ultrasound lessens the total number of digital examinations
needed to be performed during labor and, consequently, the incidence of intrapartum
fever and chorioamnionitis are reduced. No adverse effects on labor progression and
short-term maternal or neonatal outcomes were noted.
Key words
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to American Journal of Obstetrics & Gynecology MFMAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- The maternal-fetal medicine units cesarean registry: chorioamnionitis at term and its duration-relationship to outcomes.Am J Obstet Gynecol. 2004; 191: 211-216
- International Multicentre Term Prelabor Rupture of Membranes Study: evaluation of predictors of clinical chorioamnionitis and postpartum fever in patients with prelabor rupture of membranes at term.Am J Obstet Gynecol. 1997; 177: 1024-1029
- Risk factors for intraamniotic infection: a prospective epidemiologic study.Am J Obstet Gynecol. 1989; 161: 562-566
- Risk factors for maternal intrapartum fever and short-term neonatal outcome.Fetal Pediatr Pathol. 2006; 25: 169-177
- Induction of labour in nulliparous women with an unfavourable cervix.BJOG. 2010; 117: 892-893
- Early versus late amniotomy for labour induction: a randomized controlled trial.J Matern Fetal Neonatal Med. 2012; 25: 2326-2329
- Six versus twelve hours of single-balloon catheter placement with oxytocin administration for labor induction: a randomized controlled trial.Am J Obstet Gynecol. 2021; 224 (611.e1–8)
- Birth simulator: reliability of transvaginal assessment of fetal head station as defined by the American College of Obstetricians and Gynecologists classification.Am J Obstet Gynecol. 2005; 192: 868-874
- Is intrapartum translabial ultrasound examination painless?.J Matern Fetal Neonatal Med. 2016; 29: 3276-3280
- Comparison between ultrasound parameters and clinical examination to assess fetal head station in labor.Ultrasound Obstet Gynecol. 2013; 41: 425-429
- A new method to assess fetal head descent in labor with transperineal ultrasound.Ultrasound Obstet Gynecol. 2009; 33: 313-319
- Intrapartum sonography to determine fetal head position.J Matern Fetal Neonatal Med. 2002; 12: 172-177
- Factors that affect ultrasound-determined labor progress in women undergoing induction of labor.Am J Obstet Gynecol. 2019; 220 (592.e1–15)
- Fetal descent in nulliparous women assessed by ultrasound: a longitudinal study.Am J Obstet Gynecol. 2021; 224 (378.e1–15)
- Intrapartum transperineal ultrasound assessment of fetal head progression in active second stage of labor and mode of delivery.Ultrasound Obstet Gynecol. 2013; 41: 430-435
- Relationship between intrapartum transperineal ultrasound measurement of angle of progression and head–perineum distance with correlation to conventional clinical parameters of labor progress and time to delivery.J Matern Fetal Neonatal Med. 2015; 28: 1476-1481
- The use of intrapartum ultrasound to diagnose malpositions and cephalic malpresentations.Am J Obstet Gynecol. 2017; 217: 633-641
- Intrapartum ultrasound at the initiation of the active second stage of labor predicts spontaneous vaginal delivery.Am J Obstet Gynecol MFM. 2021; 3100249
- Simple two-dimensional ultrasound technique to assess intrapartum cervical dilatation: a pilot study.Ultrasound Obstet Gynecol. 2013; 41: 413-418
- Can ultrasound measurements replace digitally assessed elements of the bishop score?.Acta Obstet Gynecol Scand. 2009; 88: 325-331
- Randomised Italian Sonography for occiput POSition Trial Ante vacuum (R.I.S.POS.T.A.).Ultrasound Obstet Gynecol. 2018; 52: 699-705
- Predicting the difficulty of operative vaginal delivery by ultrasound measurement of fetal head station.Am J Obstet Gynecol. 2017; 216 (507.e1–9)
- Transabdominal and transperineal ultrasound vs routine care before instrumental vaginal delivery - a randomized controlled trial.Acta Obstet Gynecol Scand. 2021; 100: 1075-1081
- Intrapartum transperineal ultrasound used to predict cases of complicated operative (vacuum and forceps) deliveries in nulliparous women.Acta Obstet Gynecol Scand. 2017; 96: 1490-1497
- Sonographic prediction of outcome of vacuum deliveries: a multicenter, prospective cohort study.Am J Obstet Gynecol. 2017; 217 (69.e1–10)
- Prediction of spontaneous vaginal delivery in nulliparous women with a prolonged second stage of labor: the value of intrapartum ultrasound.Am J Obstet Gynecol. 2019; 221 (642.e1–13)
- Intrapartum translabial ultrasound (ITU): sonographic landmarks and correlation with successful vacuum extraction.Ultrasound Obstet Gynecol. 2006; 28: 753-760
- Committee Opinion No. 712: intrapartum management of intraamniotic infection.Obstet Gynecol. 2017; 130: e95-101
- Intrapartum care of healthy women and their babies: summary of updated NICE guidance.BMJ. 2014; 349: g6886
- Transperineal ultrasonography for labor management: accuracy and reliability.Acta Obstet Gynecol Scand. 2015; 94: 760-765
- The feasibility and accuracy of ultrasound assessment in the labor room.J Matern Fetal Neonatal Med. 2019; 32: 3442-3451
- Incidence of fever in labor and risk of neonatal sepsis.Am J Obstet Gynecol. 2017; 216 (596.e1–5)
- Low rate of perinatal sepsis in term infants of mothers with chorioamnionitis.Am J Perinatol. 2016; 33: 143-150
- Refining the clinical definition of active phase arrest of dilation in nulliparous women to consider degree of cervical dilation as well as duration of arrest.Am J Obstet Gynecol. 2021; 225 (294.e1–14)
- Number of cervical examinations and risk of intrapartum maternal fever.Obstet Gynecol. 2012; 119: 1096-1101
- Logistic regression analysis of risk factors for intra-amniotic infection.Obstet Gynecol. 1989; 73: 571-575
- Modern management of clinical chorioamnionitis.Infect Dis Obstet Gynecol. 1995; 3: 123-132
- Membrane sweeping for induction of labour.Cochrane Database Syst Rev. 2005; 2005CD000451
- Stripping of membranes as a safe method to reduce prolonged pregnancies.Obstet Gynecol. 1996; 87: 927-931
Article info
Publication history
Published online: November 15, 2022
Accepted:
November 10,
2022
Received in revised form:
November 10,
2022
Received:
October 24,
2022
Footnotes
E.V. and R.L. contributed equally to this work.
The authors report no conflict of interest.
This study did not receive any funding.
This study was registered with ClinicalTrials.gov under identifier NCT04651309. The registered study title is AssessmentofLabourProgressByIntrapartumUltrasound.
This work was presented as an oral presentation at the at the 30th world congress of the International Society of Ultrasound in Obstetrics and Gynecology, held virtually, October 16–18 2020; and at the 16th annual meeting of the Israeli Society of Maternal-Fetal Medicine, (online conference), Israel, November 27, 2020.
Cite this article as: Oberman M, Avrahami I, Shoseyov NL, et al. Assessment of labor progress by ultrasound vs manual examination: a randomized controlled trial. Am J Obstet Gynecol MFM 2022.
Identification
Copyright
© 2022 Elsevier Inc. All rights reserved.
