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. 2025 May 12;17(5):e83938.
doi: 10.7759/cureus.83938. eCollection 2025 May.

Assessment of Airway Changes During Pregnancy With Ultrasonography and Clinical Airway Screening Tests: A Prospective Observational Study

Madhuri Kurdi  1 , Bhuvanvijay D  1 , Kaushic A Theerth  2 , Jagadish G Sutagatti  3 , Kavya Ananthathirtha  4
Affiliations

Assessment of Airway Changes During Pregnancy With Ultrasonography and Clinical Airway Screening Tests: A Prospective Observational Study

Madhuri Kurdi et al. Cureus. .

Abstract

Introduction: Ultrasonographic airway assessment is a promising adjunct to predict difficult intubation; however, it has been relatively less studied in obstetric cases. This study aimed to assess the progress of anatomical changes in the obstetric airway, through all the three trimesters, using ultrasound measurements and clinical screening methods.

Materials and methods: This prospective observational study included 205 women with singleton pregnancies. In clinical assessment, modified Mallampati class and neck circumference were noted. In ultrasonographic assessment, the skin-to-epiglottis distance and tongue volume were measured. In every study participant, the measurements were recorded three times, once in each of the three trimesters. The primary objective was to assess and compare the clinical and ultrasonographic airway changes during the three trimesters of pregnancy. Secondary objectives were to assess airway changes among those with pre-eclampsia and to assess clinical parameters, such as history of snoring, change of voice, and presence of facial oedema throughout the pregnancy.

Results: There was an increase in the modified Mallampati grade (p = 0.0001), neck circumference (mean difference = -0.40, p = 0.0001), skin to epiglottis distance (mean difference = -0.82, p = 0.0001), and tongue volume (mean difference = -0.84, p = 0.0001), especially during the third trimester.

Conclusion: During the course of normal pregnancy, the skin-to-epiglottis distance and tongue volume increased progressively through the trimesters, reflecting the changes in the Mallampati scores and neck circumference. These findings could help in the prediction and management of the difficult airway during various stages of pregnancy.

Keywords: airway ultrasound; modified mallampati class; neck circumference; pathophysiological changes in pregnancy; three trimesters of pregnancy.

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Conflict of interest statement

Human subjects: Consent for treatment and open access publication was obtained or waived by all participants in this study. Karnataka Institute of Medical Sciences Ethics Committee, Hubballi, issued approval 318:2022-23. This study was approved by the Institutional Ethics Committee and followed the principles of Declaration of Helsinki, 2013. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.

Figures

Figure 1
Figure 1. Ultrasonography measuring the skin-to-epiglottis distance
Figure 2
Figure 2. Ultrasonographic measurement of the tongue volume
Figure 3
Figure 3. STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) flow diagram
n - number
Figure 4
Figure 4. Comparison of weight gain in pregnancy between the first trimester, second trimester, and third trimester
dependent t-test, ** p = 0.0001
Figure 5
Figure 5. Comparison of MMP grades between the first trimester, second trimester, and third trimester
Data presented as number (percentage), Friedman test applied, *** p < 0.001 NS - not significant; MMP - modified Mallampati
Figure 6
Figure 6. Comparison of the neck circumference scores among first trimester, second trimester, and third trimester
Friedman test, post-hoc Wilcoxon signed-rank test with Bonferroni correction, *** p < 0.001 NS - not significant
Figure 7
Figure 7. Comparison of the skin-to-epiglottis distance using ultrasonography among the first trimester, second trimester, and third trimester
Friedman test, post-hoc Wilcoxon signed-rank test with Bonferroni correction, *** p < 0.001 NS - not significant
Figure 8
Figure 8. Comparison of the tongue volume scores using ultrasonography among the first trimester, second trimester, and third trimester
Friedman test, post-hoc Wilcoxon signed-rank test with Bonferroni correction, *** p < 0.001 NS - not significant
See this image and copyright information in PMC

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