Aerodynamic and Manovacuometric Vocal Measurements in Pregnant Women in the Second and Third Trimesters of Pregnancy

Abstract

To describe and to correlate the aerodynamic and manovacuometric voice measurements of pregnant women. The following evaluations were carried out on 49 pregnant women - between 18 and 40 years old - in the second and third trimesters of gestational age: respiratory muscle strength, maximum phonation time of /a/, habitual, minimum, and maximum sound pressure levels. The data were statistically described and tested for the hypothesis of no association between voice measurements and refence levels, and for the correlation between voice measurements. The maximum phonation time of /a/, and the maximum inspiratory and expiratory pressures were significantly lower than expected. The habitual, minimum and maximum sound pressure levels were significantly higher than expected. The maximum sound pressure level showed a weak positive correlation with the maximum phonation time of /a/. There were moderate positive correlations between: minimum/maximum sound pressure level and habitual sound pressure level; maximum sound pressure level and minimum sound pressure level; and maximum expiratory pressure and maximum sound pressure level. A strong positive correlation occurred between maximum expiratory pressure and maximum inspiratory pressure. The pregnant women showed a decreased maximum phonation time of /a/, decreased respiratory pressures, and increased sound pressure levels. This suggests that pregnancy affects the respiratory dynamics regarding support of phonation and respiratory strength, which may generate a possible vocal abuse with the increase in sound pressure levels without respiratory support.