European Journal of Cardiovascular Medicine

PLACENTA is a vital organ for maintaining normal pregnancy and promotes foetal development. It is a dynamic organ which unique in its development and functions. It is the only organ in the body which is derived from two separate individuals, the mother and the foetus.  Being such a vital organ, it has evoked great interest among the anatomists, pathologists and obstetricians to study this organ in details in normal pregnancies as well as in various pregnancy induced abnormalities. A morphologically normal placenta reflects a healthy foetal status and vice versa. Any structural abnormality of the placenta would adversely affect the foetus resulting in low birth weight like ither pathological conditions. The well being of the foetus is affected by many factors but a healthy placenta is the single most important factor in producing a healthy baby (Van den Broek et al., 2005; Kliman 1997). The placenta begins to form at about the seventh day after fertilization when the first cell layer of  cytotrophoblast is observed. During pregnancy, a range of problems may occur that could lead to foetal abnormalities and death. Although these problems could arise from a variety of sources including chromosome and genetic disorders of the foetus (e.g. Down’s syndrome), maternal  illness  or  behaviour  (e.g.  pre-eclampsia,   smoking),  environmental  factors  (e.g. radiation) the most important of them all is placental abnormalities (Yetter, 1998). Information on placental size, shape, consistency, completeness of the placenta, presence of accessory lobes, placental infarcts, haemorrhage, tumors may be important to the care of both mother and infant (Yetter, 1998).

The placenta is a complex multifunctional organ of mainly foetal origin with pleiotropic roles during foetal growth. It has a portion derived from the developing embryo and a maternal portion formed by the modification of the uterine lining of the mother (Yetter, 1998). During the gestational  period,  it  provides  nutrition,  gas  exchange,  waste  removal,  endocrine,  immune support and a special circulation system (Pijnenborg et al., 1983) to the developing foetus.

It separates  the  maternal  and  foetal circulation,  with  which  it  is  in  contact  through  different surfaces, i.e., the syncytiotrophoblast exposes the placenta to the maternal circulation and the foetal vascular endothelium is in contact with foetal blood (Desoye and Haugel-de, 2007).  The placenta comprises a large number of functional units called villi which contains branched  terminals of the foetal circulation allowing transfer of metabolic products. The placenta is blue- red in colour and  discoid in shape, 15- 22 cm in diameter, 2- 4 cm thick, weighs 400- 600g. (Yetter, 1998).  It is classified as chorio- allantoic since it is vascularized by vessels homologous with allantoic vessels of lower mammals; haemo-chorial because of the nature of the placenta membranes; villous because of their villi (Foidart et al., 1992) It has a maternal surface that is divided into lobules or cotyledons with irregular grooves or clefts; the  foetal surface is smooth, shiny, translucent and covered in amniotic membrane (Borton, 2006).  The foetal surface of a full term placenta is shiny, grey and consists of large opaque blood vessels distributed on the dense opalescent surface of the thickened chorion. The maternal surface has the dark red colour of venous blood.  The placenta uses about 1/3 of all the oxygen and glucose supplied to the maternal blood and the rate of protein synthesis is higher in the placenta than the liver (Kaplan, 1995).

AIMS AND OBJECTIVES

1. To explore the relationship between weight of the baby and central thickness of placenta.
2. To explore the relationship between weight of the baby and number of material cotyledons of placenta

SPECIMEN COLLECTION AND PREPARATION

The number of cotyledons on the maternal surface of placenta were observed and recorded against its specific number. Central thickness of placenta was measured by indirect method because of destructive nature of direct method. A tooth prick was used to pierce the placenta from chorionic plate to the basal plate and each thickness was measured against steel scale in centimeters and recorded.

      The birth weight obtained from the centers and categorized them into two as those with birth weight less than 2.5 kgs ( low birth weight) and those with greatee than or equal to 2.5 kgs ( normal birth weight).

MATERIALS USED: The following instruments were used to take above mentioned measurements.

1. weighing machine
2. Spreading  caliper
3. Measuring scale.
4. Tooth prick

INCLUSION CRITERIA:  Women with normal and uncomplicated pregnancy.-consecutive singleton normal deliveries, cesarean sections and mothers of age group 20-35 years

EXCLUSION CRITERIA:  Women with complicated and abnormal pregnancy congenital anomaliesencies.-maternal diseases like diabetes mellitus, hypertension, anemia, multiple pregnancies 

TYPE OF STUDY:   Cross sectional study.

STATISTICAL ANALYSIS:  All the collected data was tabulated in excel spreadsheet, processed and analysed. cotyledons and thickness were expressed in mean standard deviation and  correlated with fetal weight using  correlation coefficient r value, student t test and pearsons correlation. p value less than 0.05 will be considered as statistically significant. All statistical variables were examined to compare the means of continuous difference between infants with low birth weight and infants with normal birth weight.

Table-1

Table.1 –Mean+\sd of placental parameters

Table-2

Table.2 -Range of Placental parameters   

1. The mean placental thickness was 2.78 +/- 0.79 (SD) in fetal weight < 2.5 kgs with range of1cm to 4.5 and 2.94 +/- 0.75  (SD) in fetal weight in >2.5 kgs with range of 1 c m to 4.9 cm.

2. The mean placental cotyledons was 18+/- 3.06 (SD) in fetal weight < 2.5 kgs with range of 12 to 24 and 19.64 +/- 2.89 (SD) in fetal weight > 2.5 kgs with arrange of 14 to 26

Table-3

Table.3 –Correlation between placenta variables and fetal weight            

Table-4

Student‘t’ test was used to compare means of two groups

Table.4 ­– Student Test

Correlation between placental cotyledons and fetal weight:

There was significant positive correlation between placenta cotyledons and fetal weight.(r= 0.264, p=0.000).

Correlation between central thickness of placenta and fetal weight:

There was no significant correlation between placenta thicknesst and fetal weight.(r= 1.0, p=0.11).

1. IV. Figures

                                    Figure-1                                                                        Figure-2

                                   Figure-3                                                                           Figure-4

THICKNESS OF THE PLACENTA

The thickness of the placenta may give indirect information on the foetal-placental ratio. It may give an indication of the amount of substances (nutrients, gases) that is exchanged between the foetus and the mother.   In this study, the mean placental thickness was 2.78+\-0.79 cm (SD) with a range of 1.0cm to 4.5.0 cm in birth weight <2.5 kg and 2.94+\-0.75(SD) with range of1cm to 4.9cm(Table.1&2). About  25.15% of the individual placentae fell outside the mean range of 2.65± 0.55 cm.  Thickness of the placenta correlated significantly with  the  weight  of the foetus(r=1.0 p =0.11)(Table.3).. Borton (2006) reported a range for the term placenta to be 2 cm to 4 cm whilst (Yetter, 1998) gave the term placenta a thickness range of 2.0 cm to 2.5 cm.  Results of the present study are in the agreement with the reports of Yetter, (1998) and Borton (2006).   However, the minimum placental thickness is lower than the minimum value of Yetter (1998) and Borton (2006), Borton (2006), while the maximum thickness value is also above those of Yetter (1998) and Borton (2006).

The positive correlation between the placental thickness and the weight of the baby indicate that the factors which directly affect the weight of the baby will indirectly affect the placental thickness. These factors include nutrition, maternal genetics, maternal hemoglobin concentration gain, altitude...

NUMBER OF COTYLEDONS

The present study shows mean number of cotyledons 18+/- 3.06(SD) in birth weight < 2.5 kgs and     

19.64+/- 2.899SD) in birth  weight > 2.5 kgs(Table.1&2). The difference were statistically significant (r=0.264 p value <0.01(Table.3)

The present study compared with the study done by Sapna Shavade et al 2015 , the values of present study  were comparatively higher.  they examined 100 placentae out of which 50 in birth weight < 2.5kg groupand 50  in normal birth weight group and found that the mean number of cotyledons were 18.8+/-1.98in normal birth weight group and 16+/-2.29 in birth weight < 2.5 kgs group.   The difference were statistically significant (p value <0.05).  the placental  cotyledon number was reduced in birth weight < 2.5 kgs  group compared to normal birth weight group in this study also

The present study compared with the study done by V Kowsalya et al 2013, the values of present study were comparatively higher.  they examined 200 placentae out of which 44 in birth weight < 2.5kg group and 156  in normal birth weight group and found that the mean number of cotyledons were 15+/- 4in normal birth weight group and12+/- 3 in birth weight < 2.5 kgs group.   The difference were statistically significant (p value <0.05).  the placental  cotyledon number was reduced in birth weight < 2.5 kgs  group compared to normal birth weight group in this study also

The present study compared with the study done by Pradeep S Londhe et al 2012 , the values of present study  were comparatively higher.  they examined 374 placentae out of which 94 in birth weight < 2.5kg groupand 280  in normal birth weight group and found that the mean number of cotyledons were 16.5+/- 1.4in normal birth weight group and 14.03+/- 2.0 in birth weight < 2.5 kgs group.   The difference were statistically significant (p value <0.05).  the placental  cotyledon number was reduced in birth weight < 2.5 kgs  group compared to normal birth weight group in this study also.

The present study compared with the study done by Susmita Senapati  et al 2015 , the values of present study  were comparatively higher.  they examined 103 placentae out of which 38in birth weight < 2.5kg groupand 65 in normal birth weight group and found that the mean number of cotyledons were 14.63+/-2.6 normal birth weight group and 11.32+/-2.3 in birth weight < 2.5 kgs group.   The difference were statistically significant (p value <0.05).  the placental  cotyledon number was reduced in birth weight < 2.5 kgs  group compared to normal birth weight group in this study also.

The present study compared with the study done by Archana.M.Hatti et al 2013 , the values of present study  were comparatively higher.  they examined 100placentae out of which 50 in normal  groupand 50in study group and found that the mean number of cotyledons were 15.24+/- 3.63in normal  group and 12.60+/-2.46 in study group.   The difference were statistically significant (p value <0.05).  the placental  cotyledon number was reduced in study  group compared to normal group in this study also.

The present study compared with the study done by Pradeep S Londhe et al 2011 , the values of present study  were comparatively higher.  they examined 300 placentae out of which 150 in study groupand 150 in normal  group and found that the mean number of cotyledons were 16.09+/- 1.90in normal  group and 14.37+/- 2.56 in study group.   The difference were statistically significant (p value <0.05).  the placental  cotyledon number was reduced in study  group compared to normal  group in this study also.

Konyali et al stated that there was positive correlation between fetal weight and number of cotyledons.  Abdul Rahman  MA et al 2013 studied 240 placentae , the mean cotyledon number was 18.8 +/- 1.73 with a range of 12-22 .  Majumdar et al found that the mean of cotyledon number 17+/-2 .

According to present study, number of cotyledons were 12-26.According to crowford 1959 total number of cotyledons same through out gestation. According to various authors the maternal cotyledons number variable. according to Arey 1956, William et al 1969, Bhatnagar et al 1983 the cotyledon number is 15-20. According to Boyd and Hamilton 1970 the cotyledon number is 10 -38, according to Grays anatomy the cotyledon number is 15 -30.According to Gunapriya Raghunadh et al 2011, Nordenvall et al 2013 the paucityof  cotyledon number was observed in birth weight < 2.5 kgs . according to Majumdar et al 2005 , Zia – Ur-rahman et al 2013, Rahim yar kahn 2014 found decrease in number of cotyledons in placenta of hypertensive subjects.

Rath et al reported that intercotyledenous vasculature is altered in hypertensive placentae and leads to low birth weight. The positive correlation between the placental cotyledons and the weight of the baby indicate that the factors which directly affect the weight of the baby will indirectly affect the placental cotyledons. These factors include nutrition, maternal genetics, maternal haemoglobin concentration gain, altitude..

The study on placenta is of great importance because this is the key point from where information about the fetus can be gained. From this study it can be concluded that, in low birth weight baby the placental parameter like no of cotyledons, Placental thickness etc are comparatively lower than the placenta of normal baby. So this theorem can be applied in detection of low birth weight before delivery through advanced diagnostic procedures like ultrasound, color Doppler imaging. Also measures can be taken to reduce low birth weight child delivery, associated with its complications and thereby reducing infant mortality rate.

There was a strong relationship between the placenta and the foetus suggesting that the well being of the fetus is highly dependent on the placenta since it serves as a link between the mother and the developing foetus for nutritional support, excretory functions as well as immunological and hormonal support.

Even though the best indicator of foetal weight is placental weight, the Critical examination of the No of Cotyledons and Placental thickness immediately after delivery should be used to determine the well being of the baby.

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