Resmi, S SSamuel, ElizabethKesavachandran, CShashidhar, Shankar2002-07-052009-06-012002-07-052009-06-012002-07-05Resmi SS, Samuel E, Kesavachandran C, Shashidhar S. Effect of oral contraceptives on respiratory function. Indian Journal of Physiology and Pharmacology. 2002 Jul; 46(3): 361-6http://imsear.searo.who.int/handle/123456789/106431The present study was carried out to assess the lung functions in oral contraceptive administered women. Lung function tests were carried out with Spirometer (Vitallograph Compact II). A significant increase in vital capacity (VC) was observed in these women as compared to normal control. There was also a significant decrease in forced expiratory volume in 1 sec./vital capacity (FEV1/VC%) and forced expiratory volume in 1 sec./forced vital capacity (FEV1/FVC%) among oral contraceptive administered women as compared to controls. Further, a significant increase in peak expiratory flow rate (PEF), reduction in forced expiratory flow rate (FEF75-85%) and FEF75% were observed among oral contraceptive administered women as compared to controls. The increase in VC and PEF might be due to the synthetic form of progesterone (progestins) present in oral contraceptive pills which causes hyperventilatory changes. Synthetic progesterone during luteal phase of menstrual cycle might increase the static and dynamic volumes of lung i.e. VC and PEF. But FEF75% showed a decrease which might be due to the lower neuromuscular coordination during breathing.engAdultBody Mass IndexContraceptives, Oral, Synthetic --adverse effectsEthinyl Estradiol --adverse effectsFemaleForced Expiratory Volume --drug effectsHumansNorgestrel --adverse effectsPeak Expiratory Flow Rate --drug effectsRespiratory Function TestsRespiratory Physiological Phenomena --drug effectsVital Capacity --drug effectsClinical Trial