Sphingolipids and acylcarnitines are altered in placentas from women with gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is the most common medical complication of pregnancy and a severe threat to pregnant people and offspring health. The molecular origins of GDM, and in particular the placental responses, are not fully known. The present study aimed to perform a comprehensive characterisation of the lipid species in placentas from pregnancies complicated with GDM using high-resolution MS lipidomics, with a particular focus on sphingolipids and acylcarnitines in a semi-targeted approach. The results indicated that despite no major disruption in lipid metabolism, placentas from GDM pregnancies showed significant alterations in sphingolipids, mostly lower abundance of total ceramides. Additionally, very long-chain ceramides and sphingomyelins with twenty-four carbons were lower, and glucosylceramides with sixteen carbons were higher in placentas from GDM pregnancies. Semi-targeted lipidomics revealed the strong impact of GDM on the placental acylcarnitine profile, particularly lower contents of medium and long-chain fatty-acyl carnitine species. The lower contents of sphingolipids may affect the secretory function of the placenta, and lower contents of long-chain fatty acylcarnitines is suggestive of mitochondrial dysfunction. These alterations in placental lipid metabolism may have consequences for fetal growth and development.