PLACENTAL TRANSPORT PROTEINS AND FETAL GROWTH RESTRICTION: A BIOCHEMISTRY–PHYSIOLOGY INTERFACE

To investigate the relationship between placental transport protein expression and fetal growth restriction, highlighting the biochemical physiological mechanisms linking placental function to neonatal outcomes. Methods A prospective observational study was conducted at Khyber Girls Medical College, Peshawar, from January 2023 to January 2024. Seventy-three women were enrolled and categorized into FGR (n=35) and appropriate-for-gestational-age (AGA) groups (n=38). Maternal demographics, neonatal outcomes, and placental morphology were recorded. Placental samples were analyzed for the expression of glucose transporters (GLUT1, GLUT3), amino acid transporters (SNAT2, LAT1), fatty acid transport proteins (FATP, CD36), and ABC transporters (P-gp, BCRP) using qRT-PCR and Western blotting. Results Mothers of FGR neonates showed a higher frequency of hypertensive disorders (p=0.02). Neonates in the FGR group had significantly lower birth weight, length, and head circumference compared to controls (p<0.001). Placental weight and thickness were reduced, with infarcts and calcifications more common in FGR cases. Expression of GLUT1, GLUT3, SNAT2, LAT1, FATP, and CD36 was significantly downregulated in the FGR group (p<0.001), while P-gp and BCRP were upregulated (p<0.001). Conclusion Altered expression of placental transport proteins is strongly associated with fetal growth restriction. Reduced nutrient transporter activity coupled with increased efflux transporter expression may impair fetal supply, contributing to restricted growth. These findings underscore the importance of placental biochemistry in fetal outcomes and suggest potential avenues for therapeutic intervention.