A STUDY OF MORPHOLOGY AND GROSS ANOMALIES IN FULL-TERM PLACENTAE

Background: Placenta is an important connecting organ between the mother and fetus. It provides nutrition, gas exchange, waste removal, immune support, and endocrine functions. Since variations of the placenta result in effects on fetal development and neonatal survival it is the area of interest to be studied by anatomists, pathologists, and obstetricians. We in the current studied the placental morphology, variations, and abnormalities of the human placenta. 
Methods: The samples comprised of a collection of placentae in the Department of Anatomy of Prathima Institute of Medical Sciences, Karimnagar. Samples were collected after delivery, placentae were mopped to remove any clotted blood, and then weighed with 10 cm of the umbilical cord. The specimen is fixed in 10% formalin immediately over 24-48 hours and then subjected to thorough gross examination. 
Results: Out of n=60 placentae studied the mean weight of the placenta was found to be highest at 38 weeks of gestation with a mean surface area of 964.46 cm2 and mean weight of 463.75 Kgs. N=49(81.67%) were normal maternal conditions and history of abortions and pre-eclampsia was in n=2 cases each and oligohydramnios in n=3 cases. Among the fetal abnormalities Anencephaly, Macrostomia, MS/TS/Cerebellar hypoplasia, and holoprosencephaly with single nostril was found in n=1(1.67%) cases each. 
Conclusion: Examination of the placenta performed in the delivery room provides information that may be important to the care of both mother and infant. The findings of this assessment should be documented in the delivery records. The placenta should be submitted for pathologic evaluation if an abnormality is detected. 
Keywords: Placenta, Morphological Variations, Anencephaly, oligohydramnios, Macrostomia.


Introduction
The placenta is coined from a Latin word that means "cake", and in Greek, it is called "Plakon" which means "flat, slablike". [1] In pre-Roman languages of tribal cultures, the placenta is often referred to as the "little mother" or "grandmother". The placenta is the connecting channel formed by both maternal and fetal contributions. It is an essential biological event that shows fetal graft acceptance by the maternal immune system perfectly. Placentae are characteristic of placental mammals but are also found in some non-mammals with varying levels of development. [2] The placenta plays a crucial role during pregnancy. It is a structure where maternal and fetal tissues come in direct contact without rejection, suggesting immunological acceptance of the fetal graft by the mother. This may be due to the production of immune-suppressive cytotoxins and proteins, HLA genes which block the recognition of the conceptus as a foreign body. [3] The placenta is responsible for working as a trading post between the mother's and the baby's blood supply. Small blood vessels carrying the fetal blood run through the placenta, which is full of maternal blood. [4] Placental Medicine during postpartum time helps the mother to recover faster from childbirth. The human placenta allows the passage of IgG antibodies, thereby protecting the fetus in utero. [5] In humans, cell proliferation, differentiation, and death are the driving forces behind the process of placentation, determining the fate of trophoblast cells. Abnormality at any stage of this development may lead to improper placental function and subsequent pregnancyrelated complications. [6] The maternal surface of the placenta is divided into cotyledons with irregular grooves and the fetal surface is smooth shiny and translucent which is covered with an amniotic membrane. [7] A full-term human expelled placenta appears to be a flattened discoid mass with a circular or oval outline. The average volume is 500 ml (range 200-950 ml) the average thickness is about 23 mm and range is 10 -40 mm and the average surface area is about 30000 mm 2 . [7] The placenta also provides a reservoir of blood for the fetus, delivering blood to it in case of hypotension and vice versa, comparable to a capacitor. [8] Many scientists studied the placenta in many angles macroscopically and microscopically, as it has an influence on the growing fetus and pregnant mother and used it in therapeutics like treating post-natal, chronic infections, and supplementation of hormones in infertility and other conditions. This study is taken up to compare the morphological features of the placenta with the gestational age and weight of the fetus.

Material and Methods
This cross-sectional study was done with the samples comprised of a collection of placentae in the Department of Anatomy, from the Department of Obstetrics and Gynaecology of, Prathima Institute of Medical Sciences, Karimnagar. District Civil Hospital, Karimnagar. Institutional Ethical committee permission was obtained for the study.

Method of Collection of Specimens:
The placental specimens are studied in the Department of Anatomy. After delivery, the placenta is mopped to remove any clotted blood and then weighed with 10 cm of the umbilical cord. The specimen was fixed in 10% formalin immediately over 24-48 hours and then subjected to thorough gross examination. The shape, size, and diameter of the placenta, site of attachment of umbilical cord, and gross variations are noted in all specimens. The gestational age and fetal weight were obtained from clinical case sheets. All the available data was uploaded on an MS Excel spreadsheet and analyzed by SPSS version 21 on windows format for descriptive statistics.

Results
During the study, a total of n=60 placenta samples were obtained and included in the study. The thickness of placenta was < 2 cms in n=6(10%) and between 2 -3 cms in n=50 (83.33%) cases, and > 3 cms in n=4 (6.67%) cases. The description of the shape of the placenta and the distribution is depicted in table 1.   The attachment of the umbilical cord was studied, and it was found the cord was attached in the center in n=37(61.67%) of cases, Battledore attachment was found in n=15(25%) cases, the velamentous attachment was found in n=7(11.67%) cases, and double umbilical cords were found in n=1(1.67%) case. The measurement of the weight of the placenta in grams revealed n=13(21.67%) cases were weighted below 400 gms. N=40(66.67%) cases were having weights between 401 to 500 gms. N=5(8.33%) cases were with weight 501 -600 gms and more than 600 gms weight was found in n=2(3.33%) cases. The maternal conditions associated with placentae have been shown in table 4.  The various abnormalities of fetuses were studied we found n=56(93.33%) cases were without any abnormalities. Anencephaly, Macrostomia, MS/TS/Cerebellar hypoplasia, and holoprosencephaly with single nostril were found in n=1(1.67%) cases each. The weight of the fetus was less than Gestational Age distribution 3 Kgs in n=9(15%) cases and between 3-4 Kgs in (81.67%) cases and more than 4 Kgs in n=2(3.33%) cases.

Discussion
The placenta is the only specialized organ that belongs to two people at the same time. Although the placenta has a tremendous ability to adapt itself to disturbed conditions sometimes these compensatory changes are not sufficient for the nutrition of the fetus and will result in fetal abnormalities such as fetal growth retardation. Small fetuses have smaller placentae with substantial changes in placental morphology.
In this study we found out of n=60 placentae studied the placental thick was 2 -3 cms in 83.33% cases and 68.33% of placentae were discoid shaped. The mean circumference was between 31 -50 cms in 81.67% of cases. The mean weight of the placenta was found to be highest at 38 weeks of gestation with a mean surface area of 964.46 cm 2 and a mean weight of 463.75 Kgs. Out of n=60 cases, n=49(81.67%) were normal maternal conditions, and history of abortions and pre=eclampsia was in n=2 cases each, and oligohydramnios in n=3 cases (table 4) were found. Among the fetal abnormalities Anencephaly, Macrostomia, MS/TS/Cerebellar hypoplasia, and holoprosencephaly with single nostril was found in n=1(1.67%) cases each. The mean placental weight was found to be between 400 -600 gms in other similar studies in this field. [9][10][11][12][13] The mean placental diameter was between 16 -20 cms in n=37(61.67%) cases of this study. The importance of mean diameter is because it affects the number of nutrients, oxygen, and carbon dioxide that can be exchanged between the mother and fetus. Ohagwu et al., [14] in their study reported the mean placental diameter at term ranged from 15 cms to 25 cms, and Yetter [15] reported a higher mean diameter of 22 cms. M Gediminas [16] in his study of the relationship between insufficient fetal growth and placental thickness, cord insertion, and placental gross abnormalities concluded that placental weight and thickness are associated with intrauterine growth retardation. In most of the cases of the present study n=41(68.33%) discoid-shaped placenta, oval in 18% cases, and bilobed in 1.7%. Nobis et al., [17] in their study of placental morphology found discoid-shaped in 46% oval-shaped in 17%, and bilobed in 5%. Salafi et al., [18] found abnormal shapes are usually associated with reduced placental efficiency. An abnormal placental shape is a marker of maternal uteroplacental and/or fetoplacental vascular pathology which can affect the development of the fetus. Most of the placental weight in the current study was between 401 -500 gms in 66.67% of cases. There appears to be a significant correlation between placental weight and placental thickness and the birth weight of neonates. The thickness of the placenta has an indirect effect on the weight of the fetus and the fetoplacental ratio. The other factors that impact placental thickness include nutrition, maternal genetics, maternal hemoglobin, and altitude. Placentae with thickness lesser than 2.5 cms are found to be associated with intrauterine growth retardation and those with more thickness of 4 cms may be associated with maternal diabetes, fetal hydrops, and intrauterine fetal infections. [19] Elchalal et al., [20] determined that placental thickness during pregnancy above the 90th percentile was associated with a twofold risk of birth weight less than 2500 g. The thick placenta was also associated with birth weight above 4000 g. The risk for macrosomia in the thick placenta group was higher than in the control group.

Conclusion
Examination of the placenta performed in the delivery room provides information that may be important to the care of both mother and infant. The findings of this assessment should be documented in the delivery records. Numerous common and uncommon findings of the placenta, umbilical cord, and membranes are associated with abnormal fetal development and perinatal morbidity. The placenta should be submitted for pathologic evaluation if an abnormality is detected, or certain indications are present. The presence of abnormal creases in the placenta helps the physician to diagnose autism shortly after birth. Such early examination of the placenta can yield information that may be important in the immediate and later management of the infant and mother. This information may also be essential for the attending physician in the event of an adverse maternal or fetal outcome.