Meng D1, Sheng YH1, Lu LY2, Wu SM3
1 International Peace Maternity and Child Health Hospital, Shanghai, China
2 Dept. of Molecular Pathology, 85 Hospital of PLA, Shanghai, China

3 Shanghai Institute for Pediatric Research, Shanghai, China


Objective: Our purpose was to investigate a possible role for apoptosis in the pathophysiologic mechanisms of intrauterine growth restriction.
Methods: Placental samples were obtained from 4 uncomplicated third-trimester pregnancies and from 5 pregnancies complicated by intrauterine growth restriction, very placental sample formed into 4 blocks and paraffin embedded. The definition used to identify cases of intrauterine growth restriction depended on three criteria: clinical evidence of suboptimal growth, ultrasonographic evidence of deviation from an appropriate growth percentile, and individualized birth weight ratios <10th percentile. Light microscopy was used to quantify the evidence of apoptosis and syncytial cell. Electron microscope and TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling) staining were used to confirm the occurrence of apoptosis.
Results: For each block 10 fields of view were examined. Quantification of apoptosis and syncytial cell resulted in the following values: normal third trimester (n=200 fields of view) 4.31.8/field of view in apoptosis, 20.46.3/field of view in syncytial cell and intrauterine growth restriction third trimester (n=160 fields of view ) 4.81.8/field of view in apoptosis, 10.53.4/field of view in syncytial cell. The incidence of apoptosis was significantly higher and the incidence of syncytial cell was significantly lower in placentas from pregnancies with intrauterine growth restriction compared with normal third-trimester placentas (P<0.05, T test; and P<0.001, T test).
Conclusions: These results suggest that increased apoptosis and decreased syncytial cell may play a role in the pathophysiologic mechanisms of intrauterine growth restriction.