Respiratory tract changes during pregnancy
- Edmund F Funai, MD
Edmund F Funai, MD
- Professor and Chief Operating Officer
- USF Health
- Jonathan Gillen-Goldstein, MD
Jonathan Gillen-Goldstein, MD
- Director of Prenatal Diagnosis and Therapy
- for Madonna Perinatal Associates
- Mineola, NY
- Henry Roque, MD, MS
Henry Roque, MD, MS
- Harvard School of Medicine
- Sonya S Abdel-Razeq, MD
Sonya S Abdel-Razeq, MD
- Assistant Professor
- Department of Obstetrics, Gynecology and Reproductive Sciences, Division of Maternal-Fetal Medicine
- Department of Surgery, Division of Surgical Critical Care
- Yale University
- Section Editors
- Charles J Lockwood, MD, MHCM
Charles J Lockwood, MD, MHCM
- Section Editor — Obstetrics
- Senior Vice President, USF Health
- Dean, Morsani College of Medicine
- Professor, Obstetrics and Gynecology
- University of South Florida
- Peter J Barnes, DM, DSc, FRCP, FRS
Peter J Barnes, DM, DSc, FRCP, FRS
- Editor-in-Chief — Pulmonary, Critical Care, and Sleep Medicine
- Section Editor — Asthma
- Professor of Medicine
- National Heart and Lung Institute, Imperial College, London
The respiratory tract, similar to other organ systems, undergoes profound changes as a result of the maternal adaptation to pregnancy. Histological findings on respiratory tissues, anatomical relationships, and respiratory function are altered by the gravid uterus and the hormonal and metabolic changes of advancing gestation. Assessing a pregnant woman for respiratory illness involves understanding these changes and interpreting laboratory data in the proper context.
ANATOMIC CHANGES IN THE RESPIRATORY TRACT DURING PREGNANCY
Upper respiratory system — Histologic examination of the upper respiratory mucosa during pregnancy reveals hyperemia, glandular hyperactivity, increased phagocytic activity, and increased mucopolysaccharide content . Pregnant women often experience nasal stuffiness and epistaxis, possibly as a result of these alterations. (See "Recognition and management of allergic disease during pregnancy", section on 'Pregnancy rhinitis'.)
Some women develop benign growths in the nose during pregnancy, leading to nasal congestion and variable degrees of epistaxis . This tumor, which is almost always unilateral, is called nasal granuloma gravidarum, pregnancy tumor, pregnancy granuloma, or telangiectatic polyp. Histologic findings are similar to those in pyogenic granuloma. Nasal granuloma gravidarum resolves spontaneously after delivery in most cases, but it may be excised under local anesthesia if necessary to treat nasal obstruction or frequent bleeding.
The management of epistaxis is reviewed separately. (See "Approach to the adult with epistaxis".)
Thorax and diaphragm — Changes in the thorax and abdomen appear to occur early in pregnancy, well before simple displacement from the enlarging uterus could cause such an effect. In the first trimester, the subcostal angle can change from 68 to as much as 103 degrees [3,4], the diaphragm rises by up to 4 cm, and the chest diameter can increase 2 cm or more . Diaphragmatic excursion is not limited by the uterus, and actually increases by up to 2 cm . The net result of these changes is a more "barrel chested" appearance during pregnancy.
- Toppozada H, Michaels L, Toppozada M, et al. The human respiratory nasal mucosa in pregnancy. An electron microscopic and histochemical study. J Laryngol Otol 1982; 96:613.
- Ellegård EK. Pregnancy rhinitis. Immunol Allergy Clin North Am 2006; 26:119.
- Turner AF. The chest radiograph in pregnancy. Clin Obstet Gynecol 1975; 18:65.
- Thomson, K, Cohen, M. Studies on the circulation in normal pregnancy: II. Vital capacity observations in normal pregnant women. Surg Gynecol Obstet 1938; 66:591.
- Weinberger SE, Weiss ST, Cohen WR, et al. Pregnancy and the lung. Am Rev Respir Dis 1980; 121:559.
- Gilroy RJ, Mangura BT, Lavietes MH. Rib cage and abdominal volume displacements during breathing in pregnancy. Am Rev Respir Dis 1988; 137:668.
- Yannone ME, McCurdy JR, Goldfien A. Plasma progesterone levels in normal pregnancy, labor, and the puerperium. II. Clinical data. Am J Obstet Gynecol 1968; 101:1058.
- Liberatore SM, Pistelli R, Patalano F, et al. Respiratory function during pregnancy. Respiration 1984; 46:145.
- Milne JA. The respiratory response to pregnancy. Postgrad Med J 1979; 55:318.
- Skatrud JB, Dempsey JA, Kaiser DG. Ventilatory response to medroxyprogesterone acetate in normal subjects: time course and mechanism. J Appl Physiol Respir Environ Exerc Physiol 1978; 44:939.
- PROWSE CM, GAENSLER EA. RESPIRATORY AND ACID-BASE CHANGES DURING PREGNANCY. Anesthesiology 1965; 26:381.
- Saia B, Chizzolini M, Gaffuri E. [Change in lung volume during pregnancy]. Attual Ostet Ginecol 1968; 14:327.
- Bonica J. Principles and practice of obstetric analgesia and anesthesia. Philadelphia: FA Davis Co, 1962.
- Bonica JJ. Maternal respiratory changes during pregnancy and parturition. Clin Anesth 1974; 10:1.
- Milne JA, Mills RJ, Howie AD, Pack AI. Large airways function during normal pregnancy. Br J Obstet Gynaecol 1977; 84:448.
- McAuliffe F, Kametas N, Costello J, et al. Respiratory function in singleton and twin pregnancy. BJOG 2002; 109:765.
- Pernoll ML, Metcalfe J, Kovach PA, et al. Ventilation during rest and exercise in pregnancy and postpartum. Respir Physiol 1975; 25:295.
- Artal R, Wiswell R, Romem Y, Dorey F. Pulmonary responses to exercise in pregnancy. Am J Obstet Gynecol 1986; 154:378.
- Lim VS, Katz AI, Lindheimer MD. Acid-base regulation in pregnancy. Am J Physiol 1976; 231:1764.
- Graves, CR. Acute pulmonary complications in pregnancy. In: Textbook of Critical Care, Fink, MP, Abraham, E, Vincent, J, Kochanek, PM (Eds), Elsevier Saunders, Philadelphia 2005. p.1551.
- Wolfe LA, Weissgerber TL. Clinical physiology of exercise in pregnancy: a literature review. J Obstet Gynaecol Can 2003; 25:473.
- Heenan AP, Wolfe LA, Davies GA. Maximal exercise testing in late gestation: maternal responses. Obstet Gynecol 2001; 97:127.
- Baciuk EP, Pereira RI, Cecatti JG, et al. Water aerobics in pregnancy: Cardiovascular response, labor and neonatal outcomes. Reprod Health 2008; 5:10.
- Hernandez E, Angell CS, Johnson JW. Asthma in pregnancy: current concepts. Obstet Gynecol 1980; 55:739.
- ANATOMIC CHANGES IN THE RESPIRATORY TRACT DURING PREGNANCY
- Upper respiratory system
- Thorax and diaphragm
- FUNCTIONAL CHANGES IN THE RESPIRATORY TRACT DURING PREGNANCY
- Central changes
- Differences in lung volumes and capacities
- Gas exchange and arterial blood gases
- WOMEN WITH RESPIRATORY INSUFFICIENCY
- SUMMARY AND RECOMMENDATIONS