CLINICAL ARTICLE Frequency of asthma as the cause of dyspnea in pregnancy Katayoon Bidad a , Hassan Heidarnazhad b , Zahra Pourpak a, ⁎, Fatemeh Ramazanzadeh c , Nasrin Zendehdel d , Mostafa Moin a a Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran b National Research Institute of Tuberculosis and Lung Disease, Shaheed Beheshti University of Medical Sciences, Tehran, Iran c Vali-e-asr Reproductive Health Research Center, Tehran University of Medical Sciences, Tehran, Iran d Internal Medicine Ward, Mahdieh Hospital, Shaheed Beheshti University of Medical Sciences, Tehran, Iran abstract article info Article history: Received 19 February 2010 Received in revised form 24 May 2010 Accepted 13 July 2010 Keywords: Asthma Dyspnea Pregnancy Spirometry Objective: To estimate the prevalence of asthma among pregnant women with dyspnea. Methods: Pregnant women referred for prenatal care visits who had complaints of dyspnea were included. All pregnant women were evaluated by a respiratory specialist. Spirometry was performed by a single trained physician. Results: Asthma was diagnosed in 38.8% of participants. Dyspnea was diagnosed as being physiologic in 36.4% of cases, but 24.8% of cases were of probable asthma (spirometric values were within normal range but symptoms and signs were suggestive of asthma). Cough, wheezing, and post-exercise symptoms were significantly more prevalent in asthmatic and probable-asthmatic women than in women without asthma. Conclusion: Dyspnea in pregnancy can be physiologic, but when it is accompanied by other symptoms such as cough or wheezing it is likely to be caused by asthma. Because of the high prevalence of asthma during pregnancy, it seems logical to evaluate dyspnea via physical examination and response to bronchodilators. © 2010 Published by Elsevier Ireland Ltd. on behalf of International Federation of Gynecology and Obstetrics. 1. Introduction Symptoms of dyspnea are often described as “shortness of breath,” “difficulty breathing,” and “inability to take in enough air.” The cause of dyspnea may be increased mechanical work of ventilation or airway resistance, increased ventilator drive, increased sensory, chemical, or central nervous system stimuli, pulmonary disease, thoracomuscular dysfunction, circulatory disease, or ventilator muscle fatigue [1]. Regardless of the factors involved, dyspnea sensation varies widely depending on the pathophysiologic abnormalities involved [2,3]. Dyspnea is a common symptom among pregnant women but the diagnosis of dyspnea in pregnancy is challenging [4]. Although physicians should distinguish physiologic from pathologic dyspnea, women are often reassured that symptoms are normal in pregnancy. However, there are millions of people with asthma in low-income countries [5] and it is a common disorder among pregnant women [6]; furthermore, maternal immune changes may upgrade asthma-related mechanisms during pregnancy. The general belief that “one-third improve, one-third worsen, and one-third do not change in their asthma severity during pregnancy” is not completely accurate because it does not consider the severity of asthma before pregnancy or the new cases of asthma diagnosed during pregnancy [7]. There have been numerous studies of the mutual effects of pregnancy and asthma but, particularly in low-income countries, there have been only a small number of investigations into the real prevalence of asthma during pregnancy. The aim of the present study was to estimate asthma prevalence among pregnant women with dyspnea. 2. Materials and methods All women referred for prenatal care visits to Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran, from February to December 2008 were questioned by midwives about dyspnea symptoms. Exclusion criteria at enrollment were as follows: any pulmonary diseases other than asthma; gestational hyper- tension; multiple gestation; major congenital abnormalities; intra- uterine fetal death; and not undergoing ultrasound for confirmation of gestational age. The women who were included were referred to the Immunology, Asthma and Allergy Research Center for further evaluation. Demo- graphic, social, and medical information was collected via face-to-face interview by a trained physician (KB). Past medical history of asthma based on physician diagnosis was recorded. Height and weight were measured barefoot with minimal clothing. All participants underwent physical examination by a respiratory specialist (HH), and asthma diagnosis was made based on the National Asthma Education and Prevention Program Guidelines for the Diagnosis and Management of Asthma [8]. According to the guidelines, the presence of episodic symptoms of airflow obstruction, airway hyperresponsiveness, and International Journal of Gynecology and Obstetrics 111 (2010) 140–143 ⁎ Corresponding author. 62 Gharib Street, Keshavarz Boulevard, PO Box 14185-863, Tehran, Iran. Tel.: +98 21 66919587; fax: +98 21 66428995. E-mail address: pourpakz@tums.ac.ir (Z. Pourpak). 0020-7292/$ – see front matter © 2010 Published by Elsevier Ireland Ltd. on behalf of International Federation of Gynecology and Obstetrics. doi:10.1016/j.ijgo.2010.05.024 Contents lists available at ScienceDirect International Journal of Gynecology and Obstetrics journal homepage: www.elsevier.com/locate/ijgo