IUGR (
intrauterine growth restriction) increases the incidence of perinatal complications and, although several placental transport functions have been shown to be altered in pregnancies complicated by IUGR, the mechanism behind it is not well understood. The aim of the present study was to investigate factors in maternal and cord blood plasma from normal and IUGR-complicated pregnancies associated with the
body weight of newborns. At the time of
Caesarean section, 24 women with IUGR pregnancies were compared with a group of 30 normal controls with AGA (appropriate gestational age) fetuses who were studied at
Caesarean section, which took place 5 weeks later than IUGR pregnancies, and also to a group of 25 non-delivered gestational age-matched control pregnant women (AGA-35wk). Maternal plasma
retinol, gamma- and
alpha-tocopherol, NEFAs (non-
esterified fatty acids), and palmitic, palmitoleic, gamma-linolenic and
arachidonic acids were higher in women with IUGR pregnancies than in AGA-35wk controls, whereas stearic and alpha-
linolenic acids were lower. Smaller differences were found when comparing these variables for IUGR and AGA women. However, umbilical vein plasma
gamma-tocopherol,
cholesterol,
triacylglycerols and NEFAs were higher in the IUGR group than in the AGA group, whereas
arachidonic acid was lower. Maternal plasma
retinol and NEFAs were the only variables negatively correlated with
birthweight when multiple linear regressions were analysed. In conclusion, the increased levels of circulating
retinol and NEFAs in maternal plasma are negatively associated with birth and placental weights, which may reflect an impaired placental transfer in IUGR pregnancies. As
retinoids are involved in the control of gene transcription, it is proposed that a decrease in placental transfer of
retinol could underlie the metabolic dysfunction of IUGR pregnancies.