Objective The gut hormone peptide YY3-36 (PYY3-36), present in placental and fetal intestinal tissues, inhibits gastric and pancreatic secretion, reduces intestinal motility and mesenteric blood flow and is involved in the regulation of food intake and energy balance. We aimed to study cord blood PYY3-36 concentrations in intrauterine growth-restricted (IUGR; usually associated with decreased intestinal growth, feeding intolerance and increased incidence of necrotising enterocolitis) and appropriate-for-gestational age (AGA) pregnancies and investigate possible correlations of PYY3-36 concentrations with several demographic parameters of infants at birth.
Methods PYY3-36 concentrations were determined by radioimmunoassay in 50 mixed arteriovenous cord blood samples from IUGR (n = 14) and AGA (n = 36) singleton full-term infants.
Results No significant differences in PYY3-36 concentrations were found between groups. In both groups, PYY3-36 concentrations decreased for every gram increase in birthweight (b = −0.077, 95% CI −0.134 to −0.02, p = 0.009). PYY3-36 concentrations were significantly lower in females (b = 45.38, 95% CI −88.89 to −1.86, p = 0.041). Finally, PYY3-36 concentrations did not depend on parity or delivery mode.
Conclusions Lack of difference in PYY3-36 concentrations between IUGR and AGA groups possibly suggests that PYY3-36 may not be directly involved in the disturbances of intestinal growth and function associated with IUGR. However, the documented negative association with birth weight may imply the effect of this peptide on adiposity and energy homeostasis. Lower PYY3-36 concentrations in females may be due to stimulation of PYY3-36 receptors by oestradiol. However, as this is a pilot study, further reports are required to elucidate the role of PYY3-36 in the perinatal period.