No difference in structure between omental small arteries isolated from women with preeclampsia, intrauterine growth restriction, and normal pregnancies

OBJECTIVE: Our purpose was to investigate whether there were structural differences between omental small arteries isolated from women with preeclampsia and intrauterine growth restriction and those isolated from women with normal pregnancy. STUDY DESIGN: A pressure myograph was used to study omental small arteries isolated from women with normal pregnancy and women with preeclampsia and intrauterine growth restriction (n = 16, 13, and 8, respectively). With the use of a transilluminating system, lumen diameter, wall thickness, wall/lumen ratio, distensibility, and the stress-strain relationship were studied through pressure ranges of 5 to 100 mm Hg. Arteries were then fixed with glutaraldehyde at the predelivery mean arterial pressure and embedded in epoxy resin. One-micrometer transverse sections were cut for more detailed morphologic examination. RESULTS: Wall thickness, lumen diameter, wall/lumen ratio, distensibility, and the stress-strain relationship of omental small arteries did not differ between patient groups (P > .05; repeated-measures analysis of variance). Detailed histologic examination confirmed these findings. CONCLUSIONS: Alterations in systemic vascular resistance associated with compromised pregnancies are unlikely to result from or produce an alteration in the structure of omental small arteries.