Tehran University of Medical Sciences Journal of Biostatistics and Epidemiology 2383-4196 7 1 2021 05 18 60 69 Adem Doganer Department of Biostatistics and Medical Informatics, Faculty of Medicine, Kahramanmaras Sutcu Imam University, Kahramanmaras, Turkey Abdullah Tok Deparment of Obstetric and Gynecology, Faculty of Medicine, Kahramanmaras Sutcu Imam University, Kahramanmaras, Turkey Gulbahtiyar Demirel Department of Midwifery, Faculty of Health Sciences, Sivas Cumhuriyet University, Turkey. 2021 02 12 2021 03 14 Introduction: This study compared the outcomes of cognitive function assessments between pregnant and non-pregnant women groups to demonstrate alterations occurring during pregnancy. Furthermore, we aimed to determine the factors acting on cognitive functions in pregnant women.  Material and Methods: 42 pregnant and 42 non-pregnant women were included in the study. In order to compare cognitive performances, Montreal Cognitive Assessment test was applied to women.  Results: The assessed scores of cognitive functioning were significantly different between pregnant and non-pregnant women (p <0.001). The test value was obtained as 22.29±4.57 with pregnants and as 26.02±2.19 with non-pregnant womens. The cognitive measurements yielded lower scores in the pregnant women. A negative correlation was found between the progesterone hormone levels and cognitive scores (p = 0.025). Progesterone hormone, TSH hormone and age of the pregnant were found to be important among the factors affecting the cognitive performances in pregnants (p=0.04; p=0.001; p=0.033, respectively).  Conclusion: Significant reductions in cognitive functions are observed in women during pregnancy. During pregnancy, in order to increase the cognitive level of women, hormonal values of pregnant women should be followed https://jbe.tums.ac.ir/index.php/jbe/article/view/446