Histological study of human placenta in ultrasonically determined cases of intrauterine growth retardation

ABSTRACT

To study the light microscopic structure of human placenta in ultrasonically determined cases of intrauterine growth retardation [IUGR]. A cross sectional comparative study. This study was carried out at military hospital Rawalpindi from Jan 2002 to June 2002. Ten placenta of normal and 30 placentae of known intrauterine growth retardation cases were used in this cross sectional comparative study. Placentae were weighed and cut along their maximum diameter into two halves after trimming the membranes. Three specimens were taken one from the center [A], one from the peripheral margin [C] and one from midway between the two [B]. Specimens were further processed for paraffin sections, 5micro m thick sections were made on rotary microtome. Haematoxylin and eosin [H and E], periodic acid schiff [PAS] and Masson's trichrome stains were used. The morphology of villi was observed and syncytial knots and capillaries were counted. In comprehensive study of the gross observations of the 30 placentae of IUGR cases, it was noted that all [100%] had meconium staining with presence of marginal or retroplacental hemorrhages. Calcification was noted in 24 cases. In the control group mean number of capillaries in A, B and C regions were 114 +/- 14.56, 89 +/- 8.61 and 92 +/- 11.63 respectively. In the IUGR group mean number of capillaries in A, B and C regions were 127 +/- 6.12, 125 +/- 5.53, 122 +/- 7.16 respectively. The difference between mean number of capillaries per field in A, B and C region of control and IUGR group was significant [P<0.05]. Mean birth weight, placental weight, placental diameter and placental thickness in IUGR group was 2.7 +/- 0.200, 163 +/- 18.26, 12.8 +/- 1.18 and 1.46 +/- 0.104 respectively. Difference between placental weight diameter and thickness of normal and IUGR group was statistically significant [p<0.05]. In control group mean number of syncytial knots in A, B and C regions was 114 +/- 7.13, 93 +/- 8.44 and 93 +/- 6.80 respectively. IN IUGR group, the mean number of syncytial knots in A, B and C regions was 169 +/- 7.09, 169 +/- 8.93 and 165 +/- 44.36 respectively. These differences were statistically significant [P<0.05] In terminal villi, syncytial knots and capillaries of the IUGR cases were more in the central region as compared to in the peripheral region. The quantitative difference between syncytial knots and capillaries in IUGR and control group were statistically significant [p<0.05]