Pulmonary function in advanced uncomplicated singleton and twin pregnancy.

OBJECTIVE: Pregnancy brings about significant changes in respiratory function, as evidenced by alterations in lung volumes and capacities, which are attributable to the mechanical impediment caused by the growing foetus. This study was undertaken in order to identify changes in respiratory function during normal pregnancy and to determine whether such changes are more pronounced in twin pregnancy than in singleton pregnancy. METHODS: Respiratory function was assessed in 50 women with twin pregnancies and in 50 women with singleton pregnancies (during the third trimester in both groups), as well as in 50 non-pregnant women. We measured the following pulmonary function test parameters: FVC; FEV1; PEF rate; FEV1/FVC ratio; FEF25-75%; and maximal voluntary ventilation. RESULTS: All respiratory parameters except the FEV1/FVC ratio were found to be lower in the pregnant women than in the non-pregnant women. We found no significant differences between women with twin pregnancies and those with singleton pregnancies, in terms of respiratory function. CONCLUSIONS: Despite its higher physiological demands, twin pregnancy does not appear to impair respiratory function to any greater degree than does singleton pregnancy.

Pulmonary function in advanced uncomplicated singleton and twin pregnancy / Função pulmonar em mulheres com gestação única ou gemelar avançada e sem complicações

Objective: Pregnancy brings about significant changes in respiratory function, as evidenced by alterations in lung volumes and capacities, which are attributable to the mechanical impediment caused by the growing foetus. This study was undertaken in order to identify changes in respiratory function during normal pregnancy and to determine whether such changes are more pronounced in twin pregnancy than in singleton pregnancy. Methods: Respiratory function was assessed in 50 women with twin pregnancies and in 50 women with singleton pregnancies (during the third trimester in both groups), as well as in 50 non-pregnant women. We measured the following pulmonary function test parameters: FVC; FEV1; PEF rate; FEV1/FVC ratio; FEF25-75%; and maximal voluntary ventilation. Results: All respiratory parameters except the FEV1/FVC ratio were found to be lower in the pregnant women than in the non-pregnant women. We found no significant differences between women with twin pregnancies and those with singleton pregnancies, in terms of respiratory function. Conclusions: Despite its higher physiological demands, twin pregnancy does not appear to impair respiratory function to any greater degree than does singleton pregnancy. .

Objetivo: A gravidez traz mudanças significativas na função respiratória, evidenciada por alterações nos volumes e capacidades pulmonares, que são atribuíveis ao impedimento mecânico causado pelo feto em crescimento. Este estudo foi realizado a fim de identificar alterações na função respiratória durante a gravidez normal e determinar se tais alterações são mais pronunciadas em gestação gemelar que em gestação única. Métodos: Foi avaliada a função respiratória de 50 mulheres com gestações gemelares e de 50 mulheres com gestações únicas (durante o terceiro trimestre em ambos os grupos), bem como de 50 mulheres não grávidas. Medimos os seguintes parâmetros de função pulmonar: CVF, FEV1, taxa do PFE, relação VEF1/CVF, FEF25-75% e ventilação voluntária máxima. Resultados: Todos os parâmetros, exceto a relação VEF1/CVF, foram menores nas mulheres grávidas do que nas mulheres não grávidas.Não foram encontradas diferenças significativas entre as mulheres com gestações gemelares e aquelas com gestações únicas em relação à função respiratória. Conclusões: Apesar das demandas fisiológicas maiores da gestação gemelar, essa não parece causar um comprometimento maior da função respiratória do que a gestação única. .