MORPHOLOGICAL CHANGES IN PLACENTA OF ANAEMIC MOTHERS AND FOETAL OUTCOME .
Abstract - Anaemia in female during pregnancy is very common , it affect maternal blood leading to hypoxia ,results in Placental changes ;anaemia also exerts profound changes on the maternal circulatory system and has serious effects upon both mother and foetus . Growth of fetus is intricately linked with that of placenta , which is depended on both maternal nutritional status and the transfer of nutrients as well as oxygen . study revealed morphological abnormalities due to hypoxia comprise of some changes in placental structure like increased weight & diameter ,,thickning of placentas . Foetal outcome also affected .Low birth weight baby and premature delivery increase .All these changes occure due to compensatory phenomena for fulfill demand of o2 in fetus .
AIMS &OBJECTIVES
The present study has been carried out with following aim and objectives:
- To study morphology of placenta in non-anaemic mothers.
- Find out morphological l changes in placenta of anaemic mothers.
- Find out effect of anaemia (in mothers) over fetal outcome, gestational age and baby birth.
Benefits-
To know, it is how much important to correct anemia in antenatal period to prevent worst fetal outcome.
INTRODUCTION
Placenta is a fountainhead of human existence because it is a means for provide nutrition and exchange of gases (o2&co2) in foetus. So it is a vital organ which is absolutely essential for survival, growth & development of foetus. Through out the gestation it under go continuously change in weight ,structure, shape and function in order to support prenatal life.
It metabolic functions are complex , included foetal oxygenation, nutrition, excretion endocrinological Function (synthesis of estrogen and progesterone) detoxification of drugs, and act as a barrier by prevent many harmful bacteria and substance from reaching to foetus . So it is most potent organ; but life span is shortest .It is a most interesting but unfourtunately often ignored and misunderstood organ and known to laity as ‘after birth’.
The term placenta was introduced by Realddus Columbus who used this latin word for a ‘circular cake’ (Plakous = Placenta = cake).In the old testament the placenta was considered as external soul . It is most easily available of all human organs but not routinely subjected to detailed and critical scrutiny. The study of placenta is by necessity, retrospective in Nature. Yet it provides reflection of the hazards, the foetus has been subjected during its growth & development. The placenta is the most accurate record of infant prenatal experience.
Placenta is a focus of increasing interest in modern obstetrics because significant pathology afflict the placenta, often before affecting the foetus. Placental abnormalities therefore can be an ‘early warning system’forfoetal problems. The evaluation of planceta thus become essential in high risk pregnancy. With nations commitment for ‘Health for all’the successful outcome of all the pregnancy depended much to the horticulture of placental tree.
Any diseases either associated or aggrevates with pregnancy,likehaematological disorder, diabetes &hypertension affect placenta, which also affected morbidity and mortality statistics of pregnancy and foetal out come.
Anaemia is commonest haematological disorder that occurs in pregnancy. Severity of anaemia among expectant mothers was judged by criteria suggested by WHO and according to which a level of haemoglobin below 11 gm per dl during pregnancy is an indication of anaemia. Its prevalence is about 60% among pregnant women over worlds wide. The commonest cause of anaemia during pregnancy is iron deficiency which may be due to nutritional deficiency, or increased demand. Disproportionate increase in plasma volume during pregnancy causes dilutional or physiological anaemia. The physiological anaemia starting from 6th week onwards but manifest by 8thweek of pregnancy, and progresses till 34th week and is aggravated if undernutrition taken by mother. Anaemia leading to hypoxia ,results in placental changes; anaemia also exerts profound changes on the maternal circulatory system and has serious or even lethal effects upon both mother and foetus.
In present study we find out morphological & histological changes in placenta of anaemic mothers and its effects on foetal out come.
Before advent of ultra sonography its evaluation was only possible after delivery. The evaluation of placenta has thus become essential in high risk pregnancy.
In the whole world, perinatal mortality associated directly due to pregnancy is 18/ 1000 live births. Whereas due to indirect causes is low. In India the rate is high 46/1000 live births .
Whether the factors determining the rate were related to the launch of newer antibiotics, better nutrition of mother, ante natal care, more understanding of medical disorders associated with pregnancy, is hard to determine. But in no means, the role of PLACENTA remains central in the very basic outcome of 38-40 weeks of intra uterine foetus.
As most of the perinatalfoetal deaths, were related to the insufficient o2 supply in utero, placenta plays a pivotal role in the transport of o2 to the foetus. Though this is just not the only role attributed to it, it remains major path finder for the ultimate goal of healthy foetal outcome.
It was suggested that a test of placental efficiency is urgently required ( by U.S.G. and colourdoppler) and could be of fundamental importance in progress of foetus. To establish such a test, placental structure and function must be considered together. The study of development and structure of human placenta must be of wide interest.
Though the placenta is a organ of very limited life span, yet our information on the factors limiting the span are imprecise, it performs number of function which in other organs of body involve highly specialized tissues, including
transport of metabolites in two directions both to & from the foetus and synthesis of important hormones and proteins.
High mortality and Morbidity was always associated with low Birth Weight Babies in which the role of placenta become pivotal.
Very few research projects will involve and can offer better prospects of successful co-operation between Anatomists, Physiologists, Clinicians and Obstetricians, Pediatrics and Social Medicine.)
INTRODUCTION
Placenta is a fountainhead of human existence because it is a means for provide nutrition and exchange of gases (o2&co2) in foetus. So it is a vital organ which is absolutely essential for survival, growth & development of foetus. Through out the gestation it under go continuously change in weight ,structure, shape and function in order to support prenatal life.
It metabolic functions are complex , included foetal oxygenation, nutrition, excretion endocrinological Function (synthesis of estrogen and progesterone) detoxification of drugs, and act as a barrier by prevent many harmful bacteria and substance from reaching to foetus . So it is most potent organ; but life span is shortest .It is a most interesting but unfourtunately often ignored and misunderstood organ and known to laity as ‘after birth’.
The term placenta was introduced by Realddus Columbus who used this latin word for a ‘circular cake’ (Plakous = Placenta = cake).In the old testament the placenta was considered as external soul . It is most easily available of all human organs but not routinely subjected to detailed and critical scrutiny. The study of placenta is by necessity, retrospective in Nature. Yet it provides reflection of the hazards, the foetus has been subjected during its growth & development. The placenta is the most accurate record of infant prenatal experience.
Placenta is a focus of increasing interest in modern obstetrics because significant pathology afflict the placenta, often before affecting the foetus. Placental abnormalities therefore can be an ‘early warning system’forfoetal problems. The evaluation of planceta thus become essential in high risk pregnancy. With nations commitment for ‘Health for all’the successful outcome of all the pregnancy depended much to the horticulture of placental tree.
Any diseases either associated or aggrevates with pregnancy,likehaematological disorder, diabetes &hypertension affect placenta, which also affected morbidity and mortality statistics of pregnancy and foetal out come.
Anaemia is commonest haematological disorder that occurs in pregnancy. Severity of anaemia among expectant mothers was judged by criteria suggested by WHO and according to which a level of haemoglobin below 11 gm per dl during pregnancy is an indication of anaemia. Its prevalence is about 60% among pregnant women over worlds wide. The commonest cause of anaemia during pregnancy is iron deficiency which may be due to nutritional deficiency, or increased demand. Disproportionate increase in plasma volume during pregnancy causes dilutional or physiological anaemia. The physiological anaemia starting from 6th week onwards but manifest by 8thweek of pregnancy, and progresses till 34th week and is aggravated if undernutrition taken by mother. Anaemia leading to hypoxia ,results in placental changes; anaemia also exerts profound changes on the maternal circulatory system and has serious or even lethal effects upon both mother and foetus.
In present study we find out morphological & histological changes in placenta of anaemic mothers and its effects on foetal out come.
Before advent of ultra sonography its evaluation was only possible after delivery. The evaluation of placenta has thus become essential in high risk pregnancy.
In the whole world, perinatal mortality associated directly due to pregnancy is 18/ 1000 live births. Whereas due to indirect causes is low. In India the rate is high 46/1000 live births .
Whether the factors determining the rate were related to the launch of newer antibiotics, better nutrition of mother, ante natal care, more understanding of medical disorders associated with pregnancy, is hard to determine. But in no means, the role of PLACENTA remains central in the very basic outcome of 38-40 weeks of intra uterine foetus.
As most of the perinatalfoetal deaths, were related to the insufficient o2 supply in utero, placenta plays a pivotal role in the transport of o2 to the foetus. Though this is just not the only role attributed to it, it remains major path finder for the ultimate goal of healthy foetal outcome.
It was suggested that a test of placental efficiency is urgently required ( by U.S.G. and colourdoppler) and could be of fundamental importance in progress of foetus. To establish such a test, placental structure and function must be considered together. The study of development and structure of human placenta must be of wide interest.
Though the placenta is a organ of very limited life span, yet our information on the factors limiting the span are imprecise, it performs number of function which in other organs of body involve highly specialized tissues, including
transport of metabolites in two directions both to & from the foetus and synthesis of important hormones and proteins.
High mortality and Morbidity was always associated with low Birth Weight Babies in which the role of placenta become pivotal.
Very few research projects will involve and can offer better prospects of successful co-operation between Anatomists, Physiologists, Clinicians and Obstetricians, Pediatrics and Social Medicine.)
FULL TERM PLACENTA -
The human placenta is a flattened discoidal mass with an approximately circular or oval outline with an average weight about 500 gms. (range 200-800 gms.), average diameter 18 cms. (range15-20cms) It is thickest at centre (The original embryonic pole) and it rapidly diminishes in thickness towards its periphery. Average surface area of placenta is about 30,000 mm. The human placenta is chorio-allantoic since it is vascularzed by vessels homologous with allantoic vessels of lower mammals, Haemo-chorial because of nature of its membrane, villous because of its villi, deciduate because maternal decidua is shed at birth along with it. It has got two surfaces and a margin-the surface which was in contact with deciduabasalis is designated as the maternal surface and it appear rough, shaggey, raddish, and is subdivided by depressions of varying depth into a number of irregularly shaped areas, the so called cotyledons, which vary considerably in number, average about corresponding to major maternal vascular units (Major branches of distribution of the umbilical vessels) and this is particularly well seen in specimens which have been x-rayed after intravascular injection of radio-opaque media. The grooves correspond to the bases of incomplete placental septa.
That surface of placenta which is directed towards the cavity of the ovum is designated as the foetal surface. This surface is covered by smooth glistening amnion with an umbilical cord attached near its centre. Mottled asppearence of the subjecentChorion, to which it is closely applied, can be seen through it. Beneath the amnion and close to the attachment of the cord, the remains of the yolk sac can sometimes be identified as a minute vesicle, up to 5 mm in diameter, with a fine thread – a vestige of the yolk stalk- attached to it. The branches of umbilical vessel radiate peripherally from the cord. The margin is limited by the fused basal and chorionic plates, and is continuous with chorionlaeve. The foetal membranes extend from the margins of placenta and consist of the amnion, chorion and a thin layer of decidua.
villous placenta with associated fibrinoid matrix and the chorioamnison together with a superficial layer of the deciduacapsularis and parietalis. The chorio-amion is continous with the placenta at its margin and constitutes the membranes.
FUNCTION OF PLACENTA
Main functions of the placenta are (a) exchange of metabolic and gaseous products between maternal and fetal blood streams and (b) production of hormones.
1- Exchange of Gases
Exchange of gases, such as oxygen, carbon dioxide, and carbon monoxide, is accomplished by simple diffusion. At term the fetus extracts 20 to 30 ml of oxygen per minute from the maternal circulation, and even a short-term interruption of the oxygen supply is fatal to the fetus. Placental blood flow is critical to oxygen supply. Since the amount of oxygen reaching the fetus primarily depends on delivery not diffusion .
2- Exchange of Nutrients and Electrolytes
Exchange of nutrients and electrolytes, such as amino acids, free fatty acids, carbohydrates, and vitamins is rapid and increases as pregnancy advances.
3- Transmission of Maternal Antibodies
Maternal antibodies are taken up by pinocytosis by the syncytiotrophoblast and transported to fetal capillaries. In this manner the fetus acquires maternal antibodies of the immunoglobulin G(IgG) class against various infectious diseases and obtains passive immunity against diphtheria, smallpox, measles, and others, but not against chickenpox and whooping cough. Passive immunity is important because the fetus has little capacity to produce its own antibodies until after birth.
4- Hormone Production
By the end of fourth month of the placenta produces progesterone in sufficient amounts to maintain pregnancy if the corpus luteum is removed or fails to function properly. In all probability all hormones are synthesized in the syncytialtrophoblast. In addition to progesterone, the placenta produces increasing amounts of estrogenic hormones, predominantly estriol, until just before the end of pregnancy, when a maximum level is reached. These high levels of estrogens stimulate uterine growth and development of the mammary glands.
During the first two months of pregnancy the syncytiotrophoblast also produces human chorionic gonadotropin (hCG), which maintains the corpus luteum. This hormone is excreted by the mother in the urine, and in the early stages of gestation. Its presence is used as an indicator of pregnancy. Another hormone produced by the placenta is somatomammotropin (formerly placental lactogen) it is a growth hormone-like substance that gives the fetus priority on maternal blood glucose and makes the mother somewhat diabetogenic. It also promote breast development for milk production.
5- Detoxification of drugs.
ANAEMIA AND PREGNANCY -
Healthy pregnancy is associated with marked changes in the circulating blood that show wide variations. These physiologic adjustments include increase in the blood volume and alternations in the interacting factors involved in hemostasis.
An understanding of haematologic problems in obstetric patients require familiarity with the dramatic changes in the blood during normal gestation. Further more these changes have special relevance to the most important and potentially hazardous heamatologic problems of pregnancy namely anaemia.
Iron deficiency anaemia is the most common anaemia of pregnancy having a high incidence of 30-70% of all pregnant women. The etiology of iron deficiency anaemia in pregnancy and puerperium is related to several factor including iron loss incurred through menstrual cycle of women of child bearing age, dietary deficiency in women of lower socio ecomomic level, increase in blood volume in pregnancy, foetal demands and blood loss at delivery .
Most body iron is contained in the haemoglobin of circulating and developing red blood cells. During pregnancy the average requirement is 4 mg /day, rising from 2.5 mg in early pregnancy to 6.6 mg/day in the last trimester. By far the greatest single demand for iron is the need to expand the red cell mass. Iron is also required for the development of foetus and placenta. Total extra
requirement being of the order of 700 - 1400 mg. Absorption of iron is enhanced in the later half of pregnancy
During pregnancy the foetus requires about 400 mg of iron, an additional 150 mg being needed for the developing placenta and growing uterus, about 270 mg of iron is conserved in the absence of menstruation; making the total deficit small. It is important to distinguish between iron deficiency anaemia and the reduction in erythrocytes and haemoglobin caused by a physiologic increase in blood volume. Heamodilution alone, therefore accounts for a reduction in haemoglobin concentration of 2 gms/ 100 ml .
The decrease in haemoglobin concentration is characterized as nutritional anaemia, specially iron and folate deficiencies which are the most frequent anaemias found in the first and second trimester
There are certain biochemical and physiologic mechanism by which the placenta is able to support the growth and the development of the foetus in pregnancy anaemia .
Maternal anaemia evokes considerable placental hypertrophy which is significant because it indicates an improvement of placental function and foetal well being.
The severity of anaemia among expectant mothers was judged by the criteria suggested by WHO.
HAEMOGLOBIN LEVEL
10 gm/dl and above but below 11 gm/dl - Mild Anaemia
7 gm/dl and above but below 10 gm/dl - Moderate Anaemia
Below 7 gm/dl - Severe Anaemia
The placenta is considered to be the most important foetal organ as it is absolutely essential to foetallife .Foetus gets its nutrients from mother, so mother is put to stress on her nutrients in pregnancy. With malanourished mother foetus is also affected and the integrity of the placenta suffers.