Maternal pulmonary function and dyspnea in multifetal pregnancies

Objectives The aim of our study was to compare the pulmonary function of mu ltifetal and singleton pregnancies and to attempt the definition of a param eter that objectively assesses maternal dyspnea, and may determine the opti mal time of delivery. Methods Retrospective analysis was carried out of 69 spirometric pulmonary function tests performed between 1993 and 1999 (19 singleton, seven twin, 3 8 triplet and five quadruplet pregnancy measurements; maternal age 19-37 ye ars; pregnancy weeks 22-41). Results Among the pulmonary function parameters studied, Tiffeneau's index showed a negative and vital capacity a positive correlation with number of fetuses and/or estimated intrauterine weight. However, vital capacity, forc ed expired volume in 1 s, Tiffeneau's index, blood gases as well as blood p H levels were not significantly different in singleton, twin, triplet or qu adruplet pregnancies before or after 30 weeks of gestation. Finally, no sig nificant difference in pulmonary function measurements could be found betwe en higher-order pregnancies with or without subjective dyspnea. Thus, we fo und no clinically relevant correlation between any spirometrically measurab le pulmonary function values and pregnancy data referring to uterine size, fundal height or breathlessness. Conclusion Our data refute the hypothesis that breathlessness in multifetal pregnancy correlates with increased fundal height or results in altered pu lmonary function. As in singleton pregnancies, it appears that dyspnea in h igher-order multiple pregnancies is a subjective rather than an objective p henomenon. In absence of an objective pulmonary function parameter, clinica l judgement remains essential for the obstetric decisions.