Abbasi,S , , Moazami,M , , Bijeh,N , and Mirmajidi,S R . "Investigation of the Relationship between Physical Activity Levels, Maternal Weight (before delivery) and Serum Cortisol Level (during labor) in Nulliparous Women", The Iranian Journal of Obstetrics, Gynecology and Infertility, 18, 151, 2015, 12-19. doi: 10.22038/ijogi.2015.4625