IL4 and fetal growth restriction: This study examined the association of maternal serum IL-2, IL-4, and IL-13 levels with intrauterine growth restriction (IUGR) and umbilical artery Doppler indices.<h4>Methods</h4>This case-control study was conducted at Alavi Teaching and Referral Hospital, Ardabil, Iran, from August 2024 to June 2025.