Abstract
Background: Anemia has potential adverse effects on mother and fetus. Moderate-to-severe anemia in pregnancy reduces diaphragmatic strength and leads to exertional dyspnea.

Aims and Objective: In the present study, we tried to establish a relationship between dynamic lung functions and different degrees of anemia in pregnant women of Odisha.

Materials and Methods: A cross-sectional study was conducted during the year 2015–2016, consisting of 90 anemic pregnant females (30 in each trimester) within the age group of 20–35 years. 110 age-matched healthy pregnant women (35 in first and second and 40 in third trimester) were taken as controls. The dynamic lung function assessment was done in the subjects by Medspiror with Helios 401 software, and hemoglobin (Hb) was estimated. Forced vital capacity (FVC), forced expiratory volume (FEV1), FEV1/FVC, forced expiratory flow (FEF25–75%), peak expiratory flow rate (PEFR), and maximum voluntary ventilation (MVV) were the parameters studied. The statistical tests employed were the student’s t-test, analysis of variance, Bonferroni, Univariate linear regression, and multiple linear regression.

Results: With increasing severity of anemia, a progressive decline in dynamic lung functions was seen in anemic pregnant women. FVC, FEV1, FEF25–75%, PEFR, and MVV values showed a significant decline (P < 0.001), while FEV1/FVC value was increased from control to severe anemic pregnant subjects (P < 0.001). With post hoc Bonferroni, all the parameters were not significant when compared within control and mild anemic pregnant. FVC, FEV1, PEFR, and MVV values were significantly reduced in moderate-to-severe anemia compared to control (P < 0.001) and in severe anemia compared to mild and moderate group (P < 0.001). FEV1/FVC was significantly increased in moderate-to-severe anemia compared to control (P < 0.001) and in severe anemia compared to mild group (P < 0.01). FEF 25–75% value was only reduced in severe anemic versus control. When linear regression analysis and multiple linear regression for dynamic lung function parameters were applied, by considering Hb% as an independent variable and adjusting the effect of age, body mass index, and trimester, there was a significant positive association in all the parameters (P < 0.001), except FEV1/FVC with significant negative association with one unit change in Hb% (P < 0.001).

Conclusion: Moderate-to-severe anemia adversely affects pulmonary functions in pregnant women. Proper interventional strategies and anesthesia should be carried out to prevent adverse outcomes in anemic pregnant women.

Key words: Anemia; Dynamic Lung Functions; Pregnancy; Dyspnea