Study Of Placental Histopathology In Hypertensive Disorders Of Pregnancy And Its Correlation With Maternal And Fetal Outcome

Abstract

BACKGROUND: Placenta, being the filter bed and gateway for the exchange of nutrients and metabolic waste products between mother and foetus is a vascular organ. As the hypertensive changes affect the cardiovascular system in adults, it also has its effect on the foetus through various changes predominantly in the vasculature of placenta. These changes have a significant impact in terms of growth and development of the embryo during gestation and gets extended to postpartum in both mother and the new-born complications. OBJECTIVE: To study placental histopathology in patients with hypertensive disorders of pregnancy and correlate with maternal and fetal outcome. MATERIALS AND METHODS: The placenta with attached membranes and umbilical cord received in histopathology section of Department of Pathology from clinically diagnosed Hypertensive disorders of pregnancy would be considered for this study. Clinical details were obtained, and the cases were categorized as: Gestational Hypertension (GHTN), Mild Preeclampsia, Severe Preeclampsia, Eclampsia. The shape, size and weight of the specimen was noted. All relevant gross findings were documented. The specimens were processed according to routine histopathology protocols, 3-4m thick sections were obtained which were subjected to Haematoxylin & Eosin staining procedure. These slides were evaluated under bright field microscopy. Presence of increased syncytial knots, villous stromal fibrosis, fibrinoid necrosis, intervillous haemorrhages and calcification were analysed in 100x and 400x magnification.APGAR score and birth weight of the infant was noted. Fetoplacental weight ratio was calculated in all the cases. Maternal outcome was documented by observing for the complications. RESULTS: A total of 128 cases were included in the study, majority (n=100) of the cases were in 18 - 25 years of age group and rest 28 cases were in 26 – 30 and >30years. Among the hypertensive disorders 41.4% (n=53) were GHTN, 13.3%(n=17) were mild preeclampsia, 22.7%(n=29) were severe preeclampsia and another 22.7% (n=29) were of eclampsia. The shape of the placentae was irregular in majority of severe preeclampsia and eclampsia cases. The average placental weight was 422 gm. The average diameter was 15.1cm and mean thickness was 2.8cm. Microscopic findings like fibrinoid necrosis, intervillous haemorrhages, villous stromal fibrosis, syncytial knots and calcification were seen in 54.7 %, 43%, 41.4 %, 35.2 % and 39.1 % of cases respectively. Eight cases had IUDs and a single case of still birth which were seen predominantly in severe preeclampsia and eclampsia group. Among live births i.e. 93%, lower APGAR score (<7) was seen in 38.7% of cases. A reduced fetoplacental weight ratio (mean - 5.8) was noted. Maternal complications like DIC, HELLP syndrome and ARF was seen in 10.2% of cases. CONCLUSION: Histomorphological features of placenta like weight and diameter were considerably reduced in preeclampsia / eclampsia. Microscopic features like increased syncytial knots, fibrinoid necrosis, intervillous hemorrhages, villous stromal fibrosis and calcification were found more in severe preeclampsia / eclampsia as against GHTN/ mild preeclampsia placenta. Fetal outcome observed as low birth weight and IUDs in cases of eclampsia and preeclampsia group had a statistically significant p-value. New-born babies with APGAR score <7 were more in cases of eclampsia and severe preeclampsia groups