Trophoblast apoptosis in human term placentas from pregnancies complicated with idiopathic intrauterine growth retardation.

OBJECTIVE: To investigate proliferative, apoptotic, and antiapoptotic activity of placental trophoblast in pregnancies complicated with idiopathic intrauterine growth retardation (IUGR).
METHODS: Study group included data and placentas from 52 normal singleton term pregnancies with idiopathic IUGR. Records and placentas from 69 singleton pregnancies with normal fetal growth served as a control group. IUGR was defined by birth weight less than 10th percentile of standard values. Children with congenital malformations and those born with the signs of hypoxia, laboratory or clinical signs of preeclampsia or infection, children born to anemic mothers and those born from pregnancies with an increased coagulation system activity were excluded.
RESULTS: There was no statistically significant difference in the cytotrophoblast proliferation index value (Z = 0.24; P = 0.553), trophoblast expression of the Bcl-2 antiapoptotic factor (Z = 0.47; P = 0.634), and trophoblast apoptotic index (Z = 0.51; P = 0.613) between the idiopathic IUGR and control group.
CONCLUSION: The proliferative and apoptotic events in the trophoblast of placentas with idiopathic IUGR did not differ from physiologic ones. Study results suggest the IUGR syndrome to have no uniform etiology or even underlying pathophysiology that would determine the possible fetal risk and subsequent long-term consequences for fetal health and life. This imposes the need of a more precise definition and unambiguous distinction between the idiopathic and other forms of IUGR.