Changes in Lipid Profiles with the Progression of Pregnancy in Black Women

Abstract

Background/Objectives: Lipid metabolism plays an important role in maternal health and fetal development. There is a gap in the knowledge of how lipid metabolism changes during pregnancy for Black women who are at a higher risk of adverse outcomes. We hypothesized that the comprehensive lipidome profiles would show variation across pregnancy indicative of requirements during gestation and fetal development. Methods: Black women were recruited at prenatal clinics. Plasma samples were collected at 8-18 weeks (T₁), 22-29 weeks (T₂), and 30-36 weeks (T₃) of pregnancy. Samples from 64 women who had term births (≥37 weeks gestation) were subjected to "shotgun" Orbitrap mass spectrometry. Mixed-effects models were used to quantify systematic changes and dimensionality reduction models were used to visualize patterns and identify reliable lipid signatures. Results: Total lipids and major lipid classes showed significant increases with the progression of pregnancy. Phospholipids and glycerolipids exhibited a gradual increase from T₁ to T₂ to T₃, while sphingolipids and total sterol lipids displayed a more pronounced increase from T₂ to T₃. Acylcarnitines, hydroxy acylcarnitines, and Lyso phospholipid levels significantly decreased from T₁ to T₃. A deviation was that non-esterified fatty acids decreased from T₁ to T₂ and increased again from T₂ to T₃, suggestive of a potential role for these lipids during the later stages of pregnancy. The fatty acids showing this trend included key fatty acids-non-esterified Linoleic acid, Arachidonic acid, Alpha-linolenic acid, Eicosapentaenoic acid, Docosapentaenoic acid, and Docosahexaenoic acid. Conclusions: Mapping lipid patterns and identifying lipid signatures would help develop intervention strategies to reduce perinatal health disparities among pregnant Black women.

Keywords: African American women; lipid biomarkers; lipid profiles; metabolism; pregnancy.

Figure 1

(A) The 3D dimensionality reduction models showing overall differences in lipidome profiles with the progression of pregnancy. (A1)—unsupervised principal component score plot. (A2)—partial least square discriminant analysis score plot. One score represents one sample. Timepoints T₁ (red), T₂ (green), and T₃ (blue). (B)—Bar graphs showing significant differences in the levels of lipids at three timepoints using mixed-effects models: (B1)—An overall increase in total lipid levels was observed with the progression of pregnancy (FDR-adj p = 8.05 × 10⁻⁹. (B2)—Total phospholipid levels increased (FDR-adj p = 4.53 × 10⁻⁹). (B3)—Total Sphingolipids also increased with the progression of pregnancy (FDR-adj p = 0.000714). (B4)—Total glycerolipids increased with the progression of pregnancy (FDR-adj p = 4.38 × 10⁻¹⁰). (B5)—Total sterol lipid levels increased at timepoint 3 (FDR-adj p = 0.0326). (B6)—Total non-esterified fatty acids showed a trend of decrease at T2 and increase at T3 timepoints with the progression of pregnancy (FDR-adj p = 0.0742) (* p < 0.05, ** p < 0.01, # p < 0.1).

Figure 2

(A)—(A1) The 3D OPLS DA score plot (OPLS DA) on left showing differences in lipidome profiles at timepoints T₁ (red) and T₂(green). (A2) OPLS DA S-plot showing reliable lipid markers with high magnitude and significance; red represents higher at T₁ and green represents higher at T₂. (B)—(B1) The 3D OPLS DA score plot (OPLS DA) on left showing differences in lipidome profiles at timepoints T₁ (red) and T₃ (blue). (B2) OPLS DA S-plot showing reliable lipid markers with high magnitude and significance; red represents higher at T₁ and blue represents higher at T₃.