Upper Airways in Pregnancy: Evaluation by the Acoustic Reflection Method

Study Overview
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Brief Summary
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It is well known that airway management can be difficult during pregnancy. Increased risks for difficult intubation in pregnant women have been often reported. Thus, pregnancy is regarded as a period of high anesthesiologic risk. Generalized weight gain is a well known factor influencing the upper airway in pregnant women. However, the modifications of the airway itself are less well documented. The acoustic reflection method is based on the analysis of the reflection of a single transient planar wave allowing the analysis of the longitudinal cross-sectional area profile of the examined cavity. It is a noninvasive and harmless method. The aim of the study is to evaluate by acoustic reflection method the physiological modifications of the upper airways during pregnancy. Women enrolled in the study will undergo an acoustic recording during the first, second, and third trimester of pregnancy, as well as two days and one month after delivery. Forty pregnant women will be included in this monocentric, prospective, open labelled study. Moreover, a single acoustic recording will be performed in 10 other pregnant women undergoing an MRI for obstetrical purpose. The estimated caliber of the upper airways by MRI and acoustic method will be compared.

Official Title
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Upper Airways in Pregnancy: Evaluation by the Acoustic Reflection Method

Conditions
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Pregnancy

Intervention / Treatment
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* Device: Acoustic reflection method


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Pregnant women who attend the routine ultrasound control in our institution before 14 weeks of pregnancy will be invited to participate in the study. Women are eligible for the study if they are: healthy (no previous disease, hypertension, nor obesity), 18 years or more with a singleton live fetus at the routine ultrasound scan with a normal pregnancy. Exclusion Criteria: Pregnancy complications Multiple pregnancy High risk for preterm labor Underlying diseases that could interfere with the results (such as pre-existing upper airway problems) and participation.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Physiological modifications<br>Pregnant women who attend the routine ultrasound control in our institution before 14 weeks of pregnancy | Device: Acoustic reflection method<br>* An acoustic reflection device gives the longitudinal cross-sectional area profile along airways. It is based on the analysis of a planar acoustic wave propagating in a rigid duct connected to airway.<br>|
| MRI and acoustic<br>Women undergoing an MRI for obstetrical purpose | Device: Acoustic reflection method<br>* An acoustic reflection device gives the longitudinal cross-sectional area profile along airways. It is based on the analysis of a planar acoustic wave propagating in a rigid duct connected to airway.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Physiological modifications during pregnancy and acoustic reflection method | Main aim: to evaluate by acoustic reflection method the physiological modifications of the upper airways during pregnancy. Women enrolled in the study will undergo an acoustic recording during: the 1st, 2d, and 3d trimester of pregnancy two days after delivery one month after delivery | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| MRI and acoustic reflection method | Secondary aim: a single acoustic recording will be proposed to 10 pregnant women undergoing an MRI for obstetrical purpose. The estimated caliber of the upper airways by MRI and acoustic method will be compared. | 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pregnancy, Upper airways, Acoustic reflection method