This article reviews the respiratory functional changes that accompany pregnancy. Pregnancy induces enormous hormonal, circulatory, and mechanical alterations. The pregnant state is accompanied by increases in progesterone and estrogen with vascular and central nervous system effects, alterations in the balance of bronchoconstrictor and bronchodilator prostenoids, and increased levels of peptide hormones that alter connective tissue characteristics. Cardiac output and pulmonary blood flow are increased because of the metabolic demands of the products of conception, the increase in blood volume, and the decrease in hemoglobin concentration. The plasma oncotic pressure is decreased because of the increase in blood volume and decrease in albumin concentration. The combination of increased pulmonary blood flow, increased pulmonary capillary blood volume, and decreased oncotic pressure all promote the formation of edema in the periphery and in the lung. The course of pregnancy is accompanied by structural changes to the rib cage and abdominal compartments as a consequence of the hormonal changes and the enlarged uterus. Given the dramatic physical and hormonal alterations of pregnancy, perhaps the most remarkable aspect of respiratory physiology is the relatively minor impact that pregnancy has on the function of the lung. Over the years there have been several excellent reviews of the effects of pregnancy on the respiratory system in health and disease.<sup>23 Fishburne J.I. Physiology and disease of the respiratory system in pregnancy: A review J Reprod Med 1979 ;  22 : 177-189

Cliccare qui per andare alla sezione Riferimenti, 44 Lapinsky S.E., Kruczynski K., Slutsky A.S. Critical care in the pregnant patient Am J Respir Crit Care Med 1995 ;  152 : 427-455

Cliccare qui per andare alla sezione Riferimenti, 86 Weinberger S.E., Weiss S.T., Cohen W.R. , e al. Pregnancy and the Lung Am Rev Respir Dis 1980 ;  121 : 559-581

Cliccare qui per andare alla sezione Riferimenti, 88 Wise R.A. Pulmonary function during pregnancy Asthma and Immunological Diseases in Pregnancy and Early Infancy New York: Marcel Dekker (1998).  57

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