Decreased umbilical artery compliance and igf-I plasma levels in infants with intrauterine growth restriction - implications for fetal programming of hypertension.

Epidemiological studies link intrauterine growth restriction (IUGR) to arterial hypertension in adulthood. We compared umbilical arteries from IUGR (n=12, <5th weight percentile) vs. appropriate for gestational age (AGA) infants (n=12) using structural and functional analyses. The vessel wall area of umbilical arteries in the IUGR group was significantly smaller than in the AGA group (2.8 vs. 3.8mm(2), P<0.05). Myographic measurements showed that maximal tension [mN/mm] as well as maximal force [mN] were both significantly increased in IUGR arteries compared with AGA arteries (P<0.05). Serum levels of IGF-I, a regulator of elastin synthesis, were significantly lower in IUGR cord blood (P<0.01) than in AGA cord blood. These IGF-I serum levels correlated significantly with maximum tension in umbilical arteries (P<0.01). Low intrauterine IGF-I serum levels may account for thinner and stiffer umbilical arteries in IUGR infants in comparison to AGA infants thereby providing a potential link to arterial hypertension in adulthood.