Histomorphometric Study of Maternal Side of Placenta in Preeclampsia

Abstract

Background: Preeclampsia is a syndrome peculiar to pregnancy. It affects 5 – 7% pregnancies throughout the world. Altho-ugh the cause of preeclampsia is unknown, compelling evidence implicates the placenta and the only known cure is removing the placenta i.e. birth of the baby.
Objectives: To determine the effects of preeclampsia on the morphology of maternal side of placenta.
Materials and Methods: 25 normal placentae and 50 placentae from preeclamptic women were obtained from Lady Aitchi-son hospital Lahore. The basis of selection and distribution of preeclamptic placentae into groups was based on diastolic blo-od pressure ranging from 90 – 130 mm Hg. Placental weight and volume was measured. On histological examination, the lumen of spiral arteriole and changes in its tunica intima and media were observed.
Results: The study demonstrated that the weight and volume of placentae progressively decreased with mounting blood pressure. On histological examination significant reduction of luminal diameter of spiral arterioles and increased disruption of basement membrane at multiple sites was a feature (33 and 80% respectively) of preeclamptic placentae in groups C and D with diastolic BP 101 – 115 and 116 – 130 mm Hg respectively. Thrombosis was also present in 29 and 40% placentae in severe preeclamptic groups C and D respectively. However, hypertrophy and fibrinoid necrosis was observed even in milder cases.
Conclusions: from the study we concluded that the increase in diastolic blood pressure adversely affected the maternal side of the placentae.
Key words: Placenta, preeclampsia, diastolic blood pressure, spiral arteriole.