Proportionality of Clinical Outcome and Placental Changes to the Increasing Severity of Maternal Hypertension- An Observational Study

Abstract

Objective: Preeclampsia and eclampsia remain the major causes of maternal and perinatal mortality and morbidity worldwide, causing 12-15% of direct maternal deaths. Although preeclampsia and related hypertensive disorders of pregnancy continue to affect 8% of all pregnancies, the incidence of preeclampsia has increased 40% in recent years. This study was carried out to analyse the different placental lesions and fetal outcome in different grades of maternal hypertension and to see if there is a linear relationship of the same.

Material and method: A total of 539 placenta specimens received at the department of Pathology from October 2017 to March 2019 were collected after obtaining informed consent. Of the 539 placentas, 87 hypertensive cases were graded and grouped according to the severity as gestational hypertension, mild preeclampsia, severe preeclampsia, eclampsia, and chronic hypertension and compared with 88 normotensive cases. The gross and microscopic findings were tabulated and analysed using the Statistical Package for the Social Sciences (SPSS) software.

Results: Incidence of fetal death and growth restriction increased with increasing grade of maternal hypertension (p= 0.001). Abnormal shape of placenta (p= 0.034) and abnormal umbilical cord insertion (p= 0.028) were seen significantly more in the hypertensive group than in the normotensive group. Infarct and abnormal vasculo-syncytial membrane (p < 0.05) and abnormal villous maturation (p= 0. 039) were significantly increased in the hypertensive group than the normotensive group.

Conclusion: The incidence of adverse fetal outcome and placental changes suggestive of feto-maternal malperfusions shows a proportional trend with the increasing grade of maternal hypertension.

Figure 1

Increased percentage of fetal death with increasing grade of maternal hypertension.

Figure 2

Trend of growth restriction with increasing grade of hypertension.

Figure 3

Showing placenta of 37-week-old intrauterine dead (IUD) fetus, with maternal history of severe preeclampsia, showing large areas of chronic infarct and an area of acute parenchymal thrombus, probably because of abruption. The umbilical cord was marginally inserted and microscopy revealed the thrombus with increased syncytial knots and chorioamnionitis.

Figure 4

Showing placenta of 39-week IUD fetus with maternal history of gestational hypertension, showing multiple infarcts.

Figure 5

Showing placenta of a 29-week IUD fetus, with maternal history of eclampsia and Hemolysis, Elevated Liver enzymes, and Low Platelet count (HELLP) Syndrome, showing various stages of infarct- Acute and Remote. The fetus showed features of gross intra-uterine growth restriction. The umbilical cord was hypocoiled. Microscopy revealed infarct, increased syncytial knots and poor vasculo-syncytial membrane.

Figure 6

Showing cut section of placenta and en bloc 32-week dead fetus, with maternal history of eclampsia and severe anaemia. Placenta shows a parenchymal thrombus progressing to chronic infarct. Microscopy confirmed the gross placental changes. The en bloc fetus shows an absent left lung, cardiomegaly, splenomegaly, and hypoplastic liver. The cause of death here is multiple congenital anomalies and not the placental changes due to hypertension.

Figure 7

Infarct (%) in different grades of maternal hypertension.

Figure 8

Syncytial knots and vasculo-syncytial membrane status in increasing grades of maternal hypertension.

Figure 9

Showing microscopic images of a case of antepartum eclampsia, A) Obliterated and spasmodic blood vessels in a stem villus (100x magnification), B) Acute atherosis of blood vessels with infiltration by foamy cells (300x), C) Congested blood vessels and haemorrhage with increased syncytial knots (400x), D) Crowded and congested villi with increased syncytial knots (10x).

Figure 10

Showing microscopic images of a case of severe preeclampsia diagnosed at 26 week of gestation. A) Crowded villi with increased syncytial knots and perivillous fibrin (40x), B) Increased syncytial knots (400x), C) Area of infarct showing ghost villi as compared with the surrounding normal villi (10x), D) Ghost villi (100x), E) Obliterated vessels (40x), F) Acute atherosis with infiltration by foamy cells (400x).