Quantitative Analysis of Gross Morphology of Placenta in Normal and Hypertensive Patients

Background: Placenta is an important organ and the growth and development of fetus is dependent on it. The different pregnancy complications as antepartum haemorrhage, postpartum haemorrhage, coagulopathy etc. in mothers and IUGR (intrauterine growth retardation), prematurity etc. in foetus are reflected in the placenta & are associated with pregnancy induced hypertension (PIH) . They form the major causes of maternal and fetal mortality & morbidity. Objectives: Quantitative analysis of the changes in gross morphology of placenta in normal and hypertensive pregnancies. To study the resultant effect on the foetal outcome. Material & Methods: We had taken 100 placentas of normal & hypertensive group patients each for study .We collected them from the labour room & operation theatre of Dept. of Obstetrics & Gynaecology of our medical college. Gross morphological features of placentas like size, weight, no. of cotyledons , areas of infarction, retroplacental clot, calcification and insertion of umbilical cord etc. were noted and simultaneously the histological study was also done. Observations & Results: The gross morphological parameters like diameter, size, surface area, Original Research Article Yadgire et al.; JPRI, 33(63B): 224-235, 2021; Article no.JPRI.80826 225 number of cotyledons and weight were reduced in hypertensive placentas than normal placentas while areas of infarction, retroplacental clot, calcification were more in hypertensive placentas than normal placentas. (p<0.005) The observed differences were statistically significant.


INTRODUCTION
Each and every organism exhibits reproduction as a feature. We all know that 'mother and foetus' are the two important ends of this process . The exhistence of foetus in the intrauterine life is dependent on the important organ i.e. 'Placenta'.
The hypertensive disorder in pregnancy also known as preeclampsia is a multisystem disorder having symptom complex of raised blood pressure, oedema and / or proteinuria [1] and affects 5-7% of all pregnancies worldwide.
Generally we study the hypertensive disorders in pregnancy as five types :  Gestational hypertension  Preeclampsia  Eclampsia  Preeclampsia superimposed on chronic hypertension 5.Chronic hypertension The development of placenta as well as the development of foetus is affected by the PIH .The size and weight of placenta decreases as pregnancy induced hypertension severity increases [2].
There is also a significant rise in the incidence of intrauterine growth retardation and still birth when the placental weight is on lower side. With low placental weight, low birth weight is observed [3]. Preeclampsia begins to abate with the delivery of the placenta because the root cause of preeclampsia is the placenta i.e. presence of trophoblast tissue [4].
It is generally believed that in preeclampsia there is impairment of trophoblast invasion . So ''preeclampsia'' is associated with abnormally shallow placentation [5]. That means the hypoinvasive placental phenotype is the characteristic of preeclampsia [6].
This reduced invasion of the trophoblasts is supposed to be the main important factor in the development of intrauterine growth retardation of the foetus and preeclampsia in mother.
This ultimately results into unfavorable outcome of the pregnancy increasing the maternal and perinatal morbidity and mortality. In this study, we observed gross changes in hypertensive placentas so as to compare them with the placentas of normal pregnancies both quantitatively and qualitatively and also study their effect on foetal outcome.

MATERIALS AND METHODS
The placentas were collected from the labour room and operation theatre of Department of Obstetrics and Gynaecology of our medical college. The gross features of the placentas such as weight, size, infarction, calcification or any retro placental clot were noted. Foetal gross observation done and findings noted like APGAR score, weight ,reflexes, maturity etc. APGAR score is calibrated by colour, cry, activity, heart rate and muscle tone of the baby. Low APGAR generally denotes birth asphyxia of the baby.
Also, for the histological study, biopsies of 5mm. size were taken from the centre as well as from the peripheral part of each placenta.
The following steps were followed:

OBSERVATIONS AND RESULTS
The present study entitled was carried out in the department of Anatomy .The placentas were collected from the labour room and operation theatre immediately after parturition and stored in 10% formal saline and subjected to gross morphological study and subsequently tissues were collected for histological study. Two sets having 100 placentas each were taken for the study.
The Placentas were studied in the following Groups: Group I -Normal Pregnancy Group II -Pregnancy with history of PIH (Pregnancy Induced Hypertension).
In our study, in hypertensive pregnancy 62 % of patients were below 36 (32)(33)(34)(35)(36) weeks of gestation i.e. preterm and In normal group , 63 % were between 37-41 wks i.e. full term. This shows that the proportion of preterm gestation and prematurity is more in patients of hypertension in pregnancy. So, when we studied the morphology of placenta, we recorded the weight (gm) and the size i.e. diameter (cm) of placenta and observed that in both the parameters, the values were lower in the hypertensive group as compared with the normal.
In normal group 63% placentas had above 20 cotyledons and 37% had below 20 of cotyledons . According to our study ,we observed that in hypertensive group there were less no of cotyledons i.e. only16% placentas had above 20 cotyledons while 84% of the placentas had below 20 cotyledons. (some even had less than 15 cotyledons.) So the mean no. of cotyledons in normal group was 21. 45 and in hypertensive group was 18. 28.  In normal patients 91% patients had central insertion of cord and 8% patients had eccentric insertion of cord and 1% only with marginal insertion .While in hypertensive patients there were 80% placenta with central insertion of cord, 2% with eccentric and 18% with marginal insertion. We noted that marginal insertion was a characteristic feature of hypertensive placentas .

Fig. 3. Observed difference was statistically significant
When we inspected the maternal surface of the placentas we found, there was only one% patient with retroplacental clot in the normal group and there were 14 % patients with retroplacental clot in hypertensive group.
In our study, 33 out of 100 patients were having calcification in normal group, while in hypertensive group, there were 47 patients with calcification of the placenta.
The mean birth weight in newborns of normal group was 2830 gm and in hypertensive gp was 2350 gm.     In above table, we observed that no. of babies with asphyxia in normal patients was only 5% and in hypertensive patients was 44%. So the proportion of asphyxia in newborn in hypertensive patients was more as compared with normal patients.
In our study, there were only 2% stillbirth babies in normal patients & in hypertensive patients no. of stillbirth babies were 15% .So the proportion of stillbirths was higher in hypertensive patients as compared with normal.

DISCUSSION
Various authors have studied the gross morphological features of placentas. In our study, the gestational age at the time of delivery ranged from 32-41 weeks in both groups. It was observed that 62% of PIH cases had preterm delivery (below 36 wks). This suggests that, maximum patients of the hypertensive group were of preterm gestational age. Our findings were similar to maham aklaq [7] and vasslliki krivelessi [8].
Figen Barut And Aikut Barut [9] in their study mentioned that average placental weight in normal patients was 508 gm and in hypertensive patients was 404 gm. S. kotgiwar and N.Ambiye [10] and K. Devishankaran [11] found that in hypertensive patients the average placental weight was 291gm and in normal patients it was 573 gm .The placental weight was 427 gm in mild PIH and 374 gm in severe PIH as was found by Vissiellekki kressie [8].
According to Thomson et al. [12] in1969 ,birth weight of foetus and weight of placenta both were below average in preeclampsia but their ratios were slightly increased . Udania Jain in 2001 [13] and Pradeep Londhe [14] in 2011, in their study found similar finding of reduced placental weight in hypertensive group than normal group. In our study, average placental weight was 388 gm for hypertensive patients and 469 gm for normal patients.
Davies et al. [15] and Murthy et al. [16] both were of the opinion that the placental sizes assessed by area, weight or volume were significantly correlated with the weight of the neonates in case of normal delivery. The growth of the foetus is dependent upon its nutrition coming from maternal blood. The size and the surface area of the placenta available for diffusion of nutrients from mother to foetus also has effect on the foetal weight.
There were 3.5% mean areas of infarction in placentas in normal patients while 17.4% were the mean areas of infarction in hypertensive patients as studied by Dr. Pradeep Londhe [14].
There were 3.77% &16. 5% areas of infarction in normal patients and hypertensive patients respectively according to the study done by Mujumdar S. and H. Dasgupta [17].
In our study, the areas of infarction were 4% in normal patients and 44% in hypertensive patients.
The deposits of calcification were found as white or pale fine granules or clumps on the placenta .Our findings were nearly similar to Fox [18] in 1964 who found 24.6% calcification in normal group. Pushpa Goswami et al. [19] in 2012, found that mean number of calcified areas of placentas in PIH were more than those found in normal patients. Majumdar S .and Dasgupta H [17] found that mean calcified areas in placenta 4.13 + 1.15 in normal as compared to 33.3 + 3.15 number in hypertensive patients which were significant. Our findings were nearly similar with the above findings with 33 out of 100 patients were having calcification in normal group, while in hypertensive group, there were 47 patients with calcification of the placenta and we had significant ''p value".
S. Kotgirwar, M. Ambiye [10] in 2011, found out of 30 cases, incidence of eccentric insertion of cord was 18 in hypertensive group & in normal group, it was 14. However, *Deeplaxmi Salmani [20] in 2012 ,found that the eccentric insertion was more i.e. 82% in hypertensive patients while central insertion was less i.e. 18%. Pradeep Londhe [14] in 2011 found that, 11.3% of marginal insertion of cord was in hypertensive and 2.7% was in normal patients. In our study , in hypertensive group maximum no. of patients had central insertion while next common type was marginal 18% and in control group, maximum no. was central insertion followed by next common type eccentric 2%.
Our study also . shows hypertensive disorders in pregnancy affect the perinatal outcome in the form of IUGR, increased no. of asphyxiated and stillborn infants. So ,the perinatal mortality and morbidity was increased in hypertensive pregnancies in our study also.

CONCLUSION
Our study was aimed to correlate the morphological changes of the PIH(hypertensive) placentas with the outcome of pregnancy and also comparison with those of the normal group.
The birth weight of foetuses in hypertensive group were on lower side than the foetuses in the normal group and the APGAR score was also lower than normal. Low APGAR generally denotes birth asphyxia of the baby.
These all studies were statistically significant . The gross changes in placentas with history of PIH were retroplacental haematoma, areas of infarction and calcification, scanty no of cotyledons. reduced size, weight and surface area of the placenta and these all changes were noted in more no. in hypertensive group than in normal group. Definitely all the above observations lead to the conclusion that there was unfavorable outcome of pregnancy in hypertensive patients. The intranatal and perinatal asphyxia was increased in hypertensive pregnancies. We know that the placenta is the mirror image of antenatal period and provides information about it. So, it is very important that we should perform the examination of placenta adequately after every delivery as a routine procedure.

CONSENT
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ETHICAL APPROVAL
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COMPETING INTERESTS
Authors have declared that no competing interests exist.