Amnion, amniotic fluid and cavity.enc

This is for Nursing students.

1. MM COLLEGE OF NURSING C LINICAL TEACHING ON AMNION, AMNIOTIC CAVITY AND AMNIOTIC FLUID SUBJECT: MIDWIFERY AND OBSTETRICIAL NURSING SUBMITTED TO : SUBMITTED BY: MRS. SIMARJEET KAUR A B I D ISMAIL ASSISTANT PROFESSOR 191 7 003 B.S C NSG 4 TH YEAR

2. INTRODUCTION OF AMNION Fetal membranes consists of two layers:- The outer covering of fetal membranes is the chorion The inner covering of the fetal membranes is the amnion

3. AMNION Amnion is the inner layer of the fetal membranes that encloses amniotic cavity. It consists of two layers:- INTERNAL SURFACE :- it is smooth, shiny and is in contact with the liquor amnii ( amniotic fluid). OUTER SURFACE :- it consists of layer of connective tissues and is apposed to similar tissue on inner aspect of chorion from which it can be peeled off.

4. AMNIOTIC CAVITY It is the closed sac between the embryo and the amnion, containing the amniotic fluid.

5. FORMATION OF AMNION AND AMNIOTIC CAVITY 8 TH DAY :- Amnion is formed as a small cavity in epiblast cells with the formation of amnioblasts . Floor of the cavity is epiblast while the roof is formed from amnioblasts . 12 th DAY :- It becomes separated from cytotrophoblasts . 4 th WEEK :- Expansion of amniotic cavity l ead to folding of the embryoic disic .

6. FORMATION OF AMNION AND AMNIOTIC CAVITY 3 rd MONTH : - Amnion comes in contact with chorion to form amnio – chorioic membrane with obliteration of chorionic cavity. By the end of the 3 rd month, uterine cavity is obliterated due to expansion of the amniotic cavity . FINALLY :- The amniotic cavity surrounds the fetus and form a tubular sheath around the umbilical cord.

7. STRUCTURE OF THE AMNION Fully formed amnion is 0.02-0.5mm in thickness From within to outwards the layers are: - single layer of cuboidal epithelium b asement of membrane compact layer of reticular structure f ibroblastic layer spongy layer The amnion has got neither blood nor nerve supply nor any lymphatic system

8. FUNCTION OF AMNION AND AMNIOTIC CAVITY Contribute to formation of amni liquor( amniotic fluid) Intact membrane prevents ascending uterine infections Facilitate dilatation of cervix during labour Has got enzymatic activities for steroid hormonal metabolism. Rich source of glycerophospholipids containing arachidonic acid precursor of prostaglandin E2 and F2.

9. AMNIOTIC FLUID Amniotic fluid is a clear, yellow fluid which is found within the first 12 days following conception within the amniotic sac. It surrounds the growing baby in the uterus.

10. COMPOSITION : ( 1) water 98–99% and (2) solid (1–2%). The following are the solid constituents: (a) Organic: Protein–0.3 mg% Total lipids–50 mg% Glucose–20 mg% Uric acid–4 mg% Hormones (prolactin, insulin and renin) Urea–30 mg% Creatinine–2 mg%

11. (b) Inorganic : - S o d i um , P o t a s s ium , C h l o r ide . (c) Suspended particles include—Lanugo, exfoliated s quamous epithelial cells from the fetal skin, vernix caseosa .

12. CIRCULATION OF AMNIOTIC FLUID The water in the amniotic fluid is completely changed and replaced in every 3 hours as shown by the clearance of radioactive sodium injected directly into the amniotic sa c .

13. VOLUME OF AMNIOTIC FLUID Amniotic fluid volume is related to the gestational age : At 12 weeks - 50ml At 20 weeks - 400ml At 36- 38 weeks - 1000ml At term - 600 – 800 ml As the pregnancy continues post term, further reduction occurs to the extends of about 200ml at 43 weeks.

14. ABNORMAL AMNIOTIC FLUID VOLUME Deviation in the normal volume has clinical significance : OLIGOHYDRAMNIOS :- It is condition where the liquor amni is deficient in amount to the extend of less than 200ml at term POLYHYDRAMNIOS :- It is the condition where the liquor amni exceeds 2 m l .

15. PHYSICAL FEATURES OF AMNIOTIC FLUID The fluid is faintly alkaline with low specific gravity of 1.010. It becomes highly hypotonic to maternal serum at term pregnancy. I n the early pregnancy it is colourless , but near term it becomes pale straw coloured due to presence of lanugo and epidermal cells from the fetal skin. It may look turbid due to presence of vernix caseosa .

16. ABNORMAL AMNIOTIC FLUID COLOUR Duration of normal colour of liquor has go clinical significance:- COLOUR REASON GREEN Meconium stained due to fetal distress GOLDEN Rh incompatibility due to excessive hemolysis of the fetal RBC GREENISH YELLOW Post maturity DARK COLOURED Concealed accidental hemorrhage is due to contamination of blood DARK BROWN Amniotic fluid found in intra uterine death, due to frequent presence of old Hb .

17. FUNCTION OF AMNIOTIC FLUID Its main is to protect the fetus :- DURING PREGNANCY Act as shock absorber Maintains an even temperature Allow for growth and free movement Prevents adhesion between the fetal part and amniotic sac

18. DURING LABOUR Helps in dilatation of cervix. Guards against umbilical cord compression. P r o t e c t s a g a inst u t e r i n e c o n tractions . S t e r i l e a m n i o tic fluid washes v a g i n a b e f o re p a s s a ge of b a b y .

19. CLINICAL IMPORTANCE Study of amniotic fluid provides information about maturity of fetus. Volume of amniotic fluid is assessed by amniotic fluid index. Rupture of membranes with drainage of liquor is a helpful method in induction of labour .

20. SUMMARY

21. CONCLUSION

22. BIBLIOGRAPHY Dutta D C “ textbook of obstetrics in nursing” published by Jaypee publisher, edition 9 th , page no. 33- 35.