The effect of intrauterine growth retardation on the expression of developmental factors in porcine placenta subsequent to the initiation of placentation.

Intrauterine growth retardation (IUGR) hinders fetal growth and postnatal development in swine; however the etiology of IUGR is essentially unknown. Expression of fourteen candidate genes associated with placental development or IUGR was examined in gestational day 50 (gd50) control and IUGR fetus whole placental tissue or areolae by real-time PCR. Endothelial nitric oxide synthase (ENOS) mRNA expression was elevated in gd50 IUGR placenta and areola compared to gd50 control. Since ENOS could modulate vascular tone and angiogenesis via nitric oxide production, data suggest that the increase in IUGR may be an adaptive response to poor perfusion to maintain pregnancy.