Plasma copeptin may not be a sensitive marker of perinatal stress in healthy full-term growth-restricted fetuses.

OBJECTIVE

Intrauterine-growth-restriction-(IUGR) is associated with chronic fetal stress, as well as a phase of enhanced fetal/early postnatal insulin sensitivity, followed by a later emergence of insulin resistance. We aimed to prospectively investigate concentrations of copeptin, a sensitive marker of stress and insulin resistance, in IUGR versus appropriate-for-gestational-age-(AGA) fetuses.

METHODS

Cord blood copeptin concentrations were determined by ELISA in well-defined, non-distressed at birth, asymmetric IUGR (n = 30) and AGA (n = 20) full-term pregnancies. Doppler studies were indicative of placental insufficiency.

RESULTS

Cord blood copeptin concentrations were similar in IUGR cases and AGA controls, after controlling for delivery mode. Copeptin concentrations were markedly elevated in vaginally delivered fetuses (p = 0.001). No association was recorded between fetal copeptin concentrations and maternal age, parity, gestational age, or fetal gender.

CONCLUSIONS

Cord blood copeptin concentrations are probably not affected by IUGR at term, in the absence of fetal distress, possibly due to a balance between copeptin up-regulation by chronic fetal stress, on one hand, and copeptin down-regulation in the presence of increased insulin sensitivity, on the other hand; thus, copeptin may not be a sensitive marker of chronic perinatal stress in healthy asymmetric IUGR infants. Cord blood copeptin seems to primarily reflect perinatal stress associated with delivery mode.