Gross morphological changes of placentas associated with intrauterine growth restriction of fetuses: a case control study.

The present study aimed to throw light to any gross morphological changes of placenta that might contribute to the development of idiopathic IUGR. Gross examination of placentas from full-term uncomplicated pregnancies delivering singleton live IUGR babies, and live normal-weight babies (controls) were performed; then the results were compared. Fifty full-term freshly delivered placentas were collected both from normal deliveries and C.S. Twenty-eight (28) placentas were associated with IUGR and twenty-two (22) were from controls. The positions of insertion of the umbilical cords, placental weights, volumes and diameters were noted. These gross examinations revealed that the control placentas were bigger in diameters, had usual positions of insertion of umbilical cords, mean placental weight was 416.77 gm and mean placental volume was 343.86 ml. In cases of IUGR placentas, there were some abnormal positions of insertion of umbilical cords in 11% placentas (marginal in 7.14% and velamentous in 3.57%), and placental weight and volume was significantly lower (p value<0.001). The placentas associated with IUGR were smaller in diameters than those of control group of placentas. The mean placental co-efficient of IUGR group in the present study was 0.156 (range 0.11-0.22) and that of the control group was 0.138 (range 0.12-0.18). The greater placental co-efficient in IUGR indicates that although both placentas and babies in IUGR had less weight, placental sizes were not relatively less. In fact, these placentas were functional, and even tried to compensate the abnormal morphology. Therefore, though IUGR fetuses were more frequently associated with morphologically abnormal placentas, it could not be conclusively decided whether this abnormal gross morphology actually contributed to the intrauterine growth restriction.