Placenta Examination PDF

Clinical Procedures Examination of the placenta Outlines:- 1- Definition 2- Mature placenta 3- The objectives 4- The clinical characteristics of normal placenta 5- Structure of the placenta 6- Surface of the placenta: 7- Functions of Placenta 8- The steps of plac...

Clinical Procedures Examination of the placenta Outlines:- 1- Definition 2- Mature placenta 3- The objectives 4- The clinical characteristics of normal placenta 5- Structure of the placenta 6- Surface of the placenta: 7- Functions of Placenta 8- The steps of placental examination: 56  Clinical Procedures Definition: Is a flat organ measuring about 17.5- 20 cm in diameter, and 2.5 cm thickness, it weight about one-six of the body birth weight at full term and formed by the 12th weeks of pregnancy. OR: Is a complex organ that originate from trophoblastic layer of the fertilized ovum. Mature placenta:  Placenta is completely formed and functioning 10-12 wks after fertilization  12-20 weeks, it weight more than the fetus because fetal organs are insufficiently developed to cope with metabolic process of nutrition.  Later in pregnancy: organs begin to function as liver, so (cytotrophoblast and syncytiotrophoblast) placenta gradually degenerate The objectives:  Identify the size, shape, consistency and completeness of the placenta.  Determine the presence of accessory lobes, placental infarcts, haemorrhage and tumors.  Assess the umbilical cord for length, insertion, number of vessels, thrombosis, knots and the presence of wharton's jelly.  Evaluate the colour and the odour of the fetal membranes The clinical characteristics of normal placenta: Diameter: 22cm at term. 57  Clinical Procedures Thickness: 2 to 2.5 cm. Weight: 470 g The umbilical cord: length: 55 to 60 cm at term Diameter: 2 to 2.5 cm. The structure: should have 2 arteries and one vein. Normal cord contains Wharton's Jelly. Surface of the placenta:  The maternal surface: dark red in colour, it should be divided in cotyledons. The structure should be complete, with no missing cotyledons.  The fetal surface: of the placenta should be shiny, gray and translucent enough to see the colour of the underlying villous tissues. Functions of Placenta 1- Respiration: No pulmonary exchange of gases can take place, so fetus must obtain oxygen and excrete carbon dioxide through placenta. Oxygen from the mother's hemoglobin passes into fetal blood by simple diffusion, for co2 also 2- Nutrition : Fetus needs nutrition for growth and development. Such as protein, carbohydrates, calcium and phosphorus, iron and minerals, these nutrients are actively transferred from the maternal to the fetal blood through wall of villi. 58  Clinical Procedures 3- Storage: The placenta metabolizes glucose, store it in the form of glycogen and reconvert it into glucose as required. It also stores iron and fat-soluble vitamins. 4- Excretion: The main substances excreted from the fetus is co2 , bilirubin excreted as red blood cells and very amount of urea and uric acid. 5- Protection: Placenta provide limited barriers to infection, some substances as alcohol, chemical of smoking cigarettes , Some virus as cytomegalovirus, and rubella are not filtered out causing congenital anomalies. 6- Endocrine : Secretes hormones such as:  Human chorionic gonadotrphin (HCG(  Oestrogen  Progestrone.  Human placental lactogen (HPL) The steps of placental examination: 1- Delivery of the placenta  As the placenta delivers, hold it in both hands and gently turn it until the membranes are twisted.  Slowly pull to complete the delivery. move membranes up and down until they deliver 59  Clinical Procedures  If the membranes tear, gently examine the upper vagina and cervix wearing sterile gloves and use a sponge forceps to remove any remaining pieces of membrane.  Place the placenta in the receptacle provided (for later examination). 2- Examination the placenta: Step 1:- Wash hands; wear an apron and gloves. Step 2: - Explain the procedure to the parents and ask if they want to observe. Step 3: - Ensure that there is adequate lighting to check the placenta. Step 4: - Prepare a flat surface with protection to avoid blood spillage. Step 5:- Prepare syringe and needle if cord samples are required. Step 6:- Lay out the placenta with the fetal surface uppermost - noting shape, size, colour and smell. Step 7: - Examine the cord, noting the length, insertion point and presence of true knots or thrombi. Step 8: - Inspect the umbilical cord vessels at the cut end at the furthest point from the placenta as the arteries can be fused around the insertion site making it difficult to differentiate them. Step 9: - Count the vessels in the cut end of the cord; the absence of one of the arteries can be associated with renal agenesis. 60  Clinical Procedures Step 10 -Observe the fetal side for irregularities such as succenturate lobes, missing cotyledons, fatty deposits or infarctions Step 11 -observe the membranes and inspect for completeness. There should be a single hole present where the baby has passed through the membranes. Step 12 -Separate the amnion from the chorion by pulling the amnion back over the base of the umbilical cord to ensure both are present. Step 13 -Turn the placenta over to inspect the maternal side. Step 14 -Examine the cotyledons, ensuring all are present, noting the size and any areas of infarction, blood clots or calcification. Retain the clots to make an accurate assessment of blood loss. The lobes of a complete placenta fit neatly together without any gaps with the edges forming a uniform circle. Broken fragments of cotyledon should be carefully replaced before making an accurate assessment, e.g. succenturate lobes, missing cotyledons, fatty deposits or infarctions. Step 15 -Take cord blood samples if required. Step 16 -Weigh, swab or take samples if indicated. Step 17 -Where there is suspicion that the placenta and/or membranes are incomplete, they should kbe kept for further inspection and referred to the duty obstetrician. Step 18 -Clean away equipment. 61  Clinical Procedures Step 19 -Wash hands. -Referral of placenta for examination may be DESIRABLE for: Prematurity (30-36 weeks) Placental abruption Fetal congenital malformation Rhesus (and other) isoimmunisation Morbidly adherent placenta Twins or other multiple pregnancy (uncomplicated) Abnormal placental shape (if clinically relevant) Two vessel cord, etc. Prolonged rupture of the membranes (more than 36 hours) Gestational diabetes Maternal group B streptococcus Pre-eclampsia/maternal hypertension Maternal coagulopathy Maternal substance abuse. Disposal of Placenta -The placenta should be placed in a yellow placenta bag then into a yellow placenta pot. -If the woman wishes to take her placenta home to bury or Encapsulate 62