Download PDF
Am J Perinatol
DOI: 10.1055/a-2022-9588
Original Article

Association between Elevated Intrauterine Resting Tone during Labor and Neonatal Morbidity

Rebecca R. Rimsza 
1   Division of Maternal-Fetal Medicine and Ultrasound, Department of Obstetrics and Gynecology, Washington University in Saint Louis, St. Louis, Missouri
,
Nandini Raghuraman
1   Division of Maternal-Fetal Medicine and Ultrasound, Department of Obstetrics and Gynecology, Washington University in Saint Louis, St. Louis, Missouri
,
Ebony B. Carter
1   Division of Maternal-Fetal Medicine and Ultrasound, Department of Obstetrics and Gynecology, Washington University in Saint Louis, St. Louis, Missouri
,
Jeannie C. Kelly
1   Division of Maternal-Fetal Medicine and Ultrasound, Department of Obstetrics and Gynecology, Washington University in Saint Louis, St. Louis, Missouri
,
Alison G. Cahill
2   Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Dell School of Medicine, University of Texas at Austin, Austin, Texas
,
Antonina I. Frolova 
1   Division of Maternal-Fetal Medicine and Ultrasound, Department of Obstetrics and Gynecology, Washington University in Saint Louis, St. Louis, Missouri
› Author Affiliations
› Further Information
    Permissions and Reprints

Abstract

Objective Internal contraction monitoring provides a quantitative assessment of intrauterine resting tone. During the course of labor, elevated intrauterine resting tone may be identified. We hypothesized that elevated intrauterine resting tone could lead to compression of the spiral arteries, thus limiting uterine blood flow and resulting in neonatal compromise. Therefore, our objective was to assess the association between elevated resting tone during labor and neonatal morbidity.

Study Design This was a secondary analysis of a prospective cohort study of singleton deliveries at ≥37 weeks of gestation. Patients with ruptured membranes and an intrauterine pressure catheter in place for at least 30 minutes prior to delivery were included. Intrauterine resting tone was calculated as the average baseline pressure between contractions during the 30 minutes prior to delivery. The study group had elevated intrauterine resting tone, defined as intrauterine resting tone ≥75th percentile (≥12.3 mm Hg). Primary outcome was composite neonatal morbidity: hypoxic–ischemic encephalopathy, hypothermia treatment, intubation, seizures, umbilical arterial pH ≤7.1, oxygen requirement, or death. Secondary outcomes included umbilical artery pH <7.2, lactate ≥4 mmol/L, and rates of neonatal intensive care unit admission.

Results Of the 8,580 patients in the cohort, 2,210 (25.8%) met the inclusion criteria. The median intrauterine resting tone was 9.7 mm Hg (interquartile range: 7.3–12.3 mm Hg). Elevated resting tone was associated with a shorter median duration of the first stage of labor (10.0 vs. 11.0 hours, p < 0.01) and lower rates of labor induction and oxytocin augmentation (p < 0.01). Neonatal composite morbidity was higher among patients with elevated intrauterine resting tone (5.1 vs. 2.9%, p = 0.01). After adjusting for chorioamnionitis and amnioinfusion, elevated intrauterine resting tone was associated with increased risk of neonatal morbidity (adjusted odds ratio: 1.70, 95% confidence interval: 1.06–2.74).

Conclusion Our findings suggest that elevated intrauterine resting tone is associated with increased risk of neonatal composite morbidity.

Key Points

  • Higher intrauterine resting tone is associated with increased risk of neonatal morbidity.

  • Elevated intrauterine tone can negatively impact umbilical artery pH and lactate levels.

  • If elevated intrauterine pressure is noted, we recommend close monitoring of fetal status.

Keywords

labor - neonatal outcomes - intrauterine pressure - intrauterine tone


Publication History

Received: 26 May 2022

Accepted: 31 January 2023

Accepted Manuscript online:
31 January 2023

Article published online:
24 February 2023

© 2023. Thieme. All rights reserved.

Thieme Medical Publishers, Inc.
333 Seventh Avenue, 18th Floor, New York, NY 10001, USA

 

  • References

  • 1 Caldeyro-Barcia R, Sica-Blanco Y, Poseiro JJ. et al. A quantitative study of the action of synthetic oxytocin on the pregnant human uterus. J Pharmacol Exp Ther 1957; 121 (01) 18-31
    PubMedGoogle Scholar
  • 2 Mol BW, Logtenberg SL, Verhoeven CJ. et al. Does measurement of intrauterine pressure have predictive value during oxytocin-augmented labor?. J Matern Fetal Neonatal Med 2016; 29 (20) 3239-3242
    PubMedGoogle Scholar
  • 3 Chua S, Kurup A, Arulkumaran S, Ratnam SS. Augmentation of labor: does internal tocography result in better obstetric outcome than external tocography?. Obstet Gynecol 1990; 76 (02) 164-167
    PubMedGoogle Scholar
  • 4 Bakker JJ, Verhoeven CJ, Janssen PF. et al. Outcomes after internal versus external tocodynamometry for monitoring labor. N Engl J Med 2010; 362 (04) 306-313
    CrossrefPubMedGoogle Scholar
  • 5 Brar HS, Platt LD, DeVore GR, Horenstein J, Medearis AL. Qualitative assessment of maternal uterine and fetal umbilical artery blood flow and resistance in laboring patients by Doppler velocimetry. Am J Obstet Gynecol 1988; 158 (04) 952-956
    CrossrefPubMedGoogle Scholar
  • 6 Janbu T, Nesheim BI. Uterine artery blood velocities during contractions in pregnancy and labour related to intrauterine pressure. Br J Obstet Gynaecol 1987; 94 (12) 1150-1155
    CrossrefPubMedGoogle Scholar
  • 7 Bailey EJ, Frolova AI, López JD, Raghuraman N, Macones GA, Cahill AG. Mild neonatal acidemia is associated with neonatal morbidity at term. Am J Perinatol 2021; 38 ( S 01 e155-e161
    Article in Thieme ConnectPubMedGoogle Scholar
  • 8 Tuuli MG, Stout MJ, Shanks A, Odibo AO, Macones GA, Cahill AG. Umbilical cord arterial lactate compared with pH for predicting neonatal morbidity at term. Obstet Gynecol 2014; 124 (04) 756-761
    CrossrefPubMedGoogle Scholar
  • 9 Frolova AI, Raghuraman N, Stout MJ, Tuuli MG, Macones GA, Cahill AG. Obesity, second stage duration, and labor outcomes in nulliparous women. Am J Perinatol 2021; 38 (04) 342-349
    Article in Thieme ConnectPubMedGoogle Scholar
  • 10 Minsart AF, Buekens P, De Spiegelaere M, Englert Y. Neonatal outcomes in obese mothers: a population-based analysis. BMC Pregnancy Childbirth 2013; 13: 36
    CrossrefPubMedGoogle Scholar
  • 11 Williams MC, O'Brien WF, Nelson RN, Spellacy WN. Histologic chorioamnionitis is associated with fetal growth restriction in term and preterm infants. Am J Obstet Gynecol 2000; 183 (05) 1094-1099
    CrossrefPubMedGoogle Scholar
  • 12 Conti N, Torricelli M, Voltolini C. et al. Term histologic chorioamnionitis: a heterogeneous condition. Eur J Obstet Gynecol Reprod Biol 2015; 188: 34-38
    CrossrefPubMedGoogle Scholar
  • 13 Posner MD, Ballagh SA, Paul RH. The effect of amnioinfusion on uterine pressure and activity: a preliminary report. Am J Obstet Gynecol 1990; 163 (03) 813-818
    CrossrefPubMedGoogle Scholar
  • 14 Fisk NM, Giussani DA, Parkes MJ, Moore PJ, Hanson MA. Amnioinfusion increases amniotic pressure in pregnant sheep but does not alter fetal acid-base status. Am J Obstet Gynecol 1991; 165 5, Pt 1 1459-1463
    CrossrefPubMedGoogle Scholar
  • 15 Sadovsky Y, Amon E, Bade ME, Petrie RH. Prophylactic amnioinfusion during labor complicated by meconium: a preliminary report. Am J Obstet Gynecol 1989; 161 (03) 613-617
    CrossrefPubMedGoogle Scholar
  • 16 Hosmer Jr. DW, Lemeshow S, Sturdivant RX. Applied Logistic Regression. 3rd ed. New York, NY: Wiley; 2013
  • 17 von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP. STROBE Initiative. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. Lancet 2007; 370 (9596): 1453-1457
    CrossrefPubMedGoogle Scholar
  • 18 Nordström L, Achanna S, Naka K, Arulkumaran S. Fetal and maternal lactate increase during active second stage of labour. BJOG 2001; 108 (03) 263-268
    PubMedGoogle Scholar
  • 19 Sato M, Noguchi J, Mashima M, Tanaka H, Hata T. 3D power Doppler ultrasound assessment of placental perfusion during uterine contraction in labor. Placenta 2016; 45: 32-36
    CrossrefPubMedGoogle Scholar
  • 20 Brotanek V, Hendricks CH, Yoshida T. Changes in uterine blood flow during uterine contractions. Am J Obstet Gynecol 1969; 103 (08) 1108-1116
    CrossrefPubMedGoogle Scholar
  • 21 Borell U, Fernstroem I, Ohlson L, Wiqvist N. Influence of uterine contractions on the uteroplacental blood flow at term. Am J Obstet Gynecol 1965; 93: 44-57
    CrossrefPubMedGoogle Scholar
  • 22 Peebles DM, Spencer JA, Edwards AD. et al. Relation between frequency of uterine contractions and human fetal cerebral oxygen saturation studied during labour by near infrared spectroscopy. Br J Obstet Gynaecol 1994; 101 (01) 44-48
    CrossrefPubMedGoogle Scholar
  • 23 Palanisamy A, Lopez J, Frolova A, Macones G, Cahill AG. Association between uterine tachysystole during the last hour of labor and cord blood lactate in parturients at term gestation. Am J Perinatol 2019; 36 (11) 1171-1178
    Article in Thieme ConnectPubMedGoogle Scholar
  • 24 Bakker PC, Kurver PH, Kuik DJ, Van Geijn HP. Elevated uterine activity increases the risk of fetal acidosis at birth. Am J Obstet Gynecol 2007; 196 (04) 313.e1-313.e6
    CrossrefPubMedGoogle Scholar
  • 25 Vlachos DE, Pergialiotis V, Papantoniou N, Trompoukis S, Vlachos GD. Oxytocin discontinuation after the active phase of labor is established. J Matern Fetal Neonatal Med 2015; 28 (12) 1421-1427
    CrossrefPubMedGoogle Scholar
  • 26 Di Mascio D, Saccone G, Bellussi F. et al. Delayed versus immediate pushing in the second stage of labor in women with neuraxial analgesia: a systematic review and meta-analysis of randomized controlled trials. Am J Obstet Gynecol 2020; 223 (02) 189-203
    CrossrefPubMedGoogle Scholar
  • 27 Bloom SL, Casey BM, Schaffer JI, McIntire DD, Leveno KJ. A randomized trial of coached versus uncoached maternal pushing during the second stage of labor. Am J Obstet Gynecol 2006; 194 (01) 10-13
    CrossrefPubMedGoogle Scholar
  • 28 Burd J, Gomez J, Berghella V. et al. Prophylactic rotation for malposition in the second stage of labor: a systematic review and meta-analysis of randomized controlled trials. Am J Obstet Gynecol MFM 2022; 4 (02) 100554
    CrossrefPubMedGoogle Scholar
  • 29 Masturzo B, Farina A, Attamante L. et al. Sonographic evaluation of the fetal spine position and success rate of manual rotation of the fetus in occiput posterior position: a randomized controlled trial. J Clin Ultrasound 2017; 45 (08) 472-476
    CrossrefPubMedGoogle Scholar
  • 30 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; 320 (14) 1444-1454
    CrossrefPubMedGoogle Scholar
  • 31 Macones GA, Hankins GD, Spong CY, Hauth J, Moore T. The 2008 National Institute of Child Health and Human Development workshop report on electronic fetal monitoring: update on definitions, interpretation, and research guidelines. J Obstet Gynecol Neonatal Nurs 2008; 37 (05) 510-515
    CrossrefPubMedGoogle Scholar