Delta‐Cell Area is Unchanged in Human Pregnancy: Evidence From Immunohistochemistry

ABSTRACT Aim Pancreatic islet δ ‐cells produce somatostatin, a paracrine regulator of insulin and glucagon secretion within islets. Although adaptive changes in α ‐ and β ‐cell populations during pregnancy have been described in both animals and humans, data on δ ‐cell plasticity are sparse and entirely lacking in human pregnancy. We aimed to determine whether pancreatic islet δ ‐cell mass undergoes morphological adaptation during human pregnancy. Methods and results Formalin‐fixed paraffin‐embedded pancreatic tissue from pregnant ( n = 7) and non‐pregnant ( n = 7) donors was analysed. Sections were immunolabelled for somatostatin to identify δ cells, and whole‐slide quantitative analysis was performed using an unbiased automated imaging pipeline. δ ‐cell area was measured across the entire pancreatic sections and compared between groups. In contrast to previously reported expansion of α ‐ and β ‐cell populations in pregnancy, δ ‐cell area was not significantly different between pregnant and non‐pregnant donors. No quantitative architectural alterations in δ ‐cell distribution within islets were observed. Conclusion Pancreatic δ ‐cell area does not increase during human pregnancy. These findings demonstrate that endocrine cell plasticity within the maternal pancreas is selective and does not uniformly involve all islet cell subtypes.