2. Learning Objectives
• Character of A.F
• Functions of A.F
• Oligo-Poly-Hydramnios
Definition
Etiology
Diagnosis
Treatment

3. The Fetal Membranes
Definition:
Fetal membranes are all the structures that develop from the
zygote and do not share in the formation of the embryo
(extraembryonic structures from the primitive blastomeres).
Fetal membranes are:
a. Chorion.
b. Amnion.
c. Yolk sac.
d. The umbilical cord including allantois and body stalk.

4. Amnion & Amniotic cavity
- It is a membrane which bounds the amniotic
cavity.
- It is continuous with the ectoderm of the embryo.
- It contains about 800-1000 ml of watery and clear
fluid at full term.

5. Amniotic Fluid
The amniotic fluid is that fluid surrounding the developing fetus
that is found within the amniotic sac contained in the mother's
womb.
• Physical characteristics ;
- It
is clear pale yellow fluid.
- pH of is around 7.2.
- Specific gravity of 1.0069 – 1.008.
-
-

6. Composition of amniotic fluid
- 98% water, 2% solid substances like inorganic &
organic salts, fetal epithelium, protein & enzymes.
Origin: The following forms the amniotic fluid:
1- Amniotic membrane
2- Maternal tissue (interstitial) fluid by diffusion across the
amnio-chorionic membrane from the deciduas parietalis.
3- Filtrated from maternal blood.
4- Fluid is also secreted by the fetal respiratory tract (300 – 400
ml daily) and enters the amniotic cavity.
5-Fetal urine.

7. Circulation
- The amniotic fluid, formed by amniotic
membrane & filtrated from maternal blood
accumulates in the amniotic cavity,
- Then, it is swallowed by the embryo.
- Lastly, it passes as fetal urine to accumulate
again in the amniotic cavity.
Volume of the amniotic fluid:
The volume of amniotic fluid increases slowly
from 30 ml at 10 weeks gestation to 350 ml at
20 weeks to 700 – 1000 ml by 37 weeks.

8. NORMAL AMNIOTIC FLUID VOLUME
Weeks Fetus Amniotic Fluid Placenta
Gestation (g) (ml) (g)
16 100 200 100
28 1000 1000 200
36 2500 900 400
40 3300 800 500

9. Function
Before labour:
1-It forms an isolating bag around the embryo protecting him
from external trauma, shock & temperature.
2-It prevents adhesion of the embryo to its membranes.
3-It allows homogenous media needed for the growth of the
embryo.
4-It permits the free movement of the embryo needed for
muscular exercise.

10. Function
During labor:
1- It forms the bags of fore water and hind water.
2-The bag of fore water allows regular dilatation of the
cervix.
3-After rupture of membrane the amniotic fluid serves
as a lubricant for fetus descent.
4-Also the amniotic fluid is bacteriostatic.

11. Clinical importance of AF:
• Screening for fetal malformation (serum α-fetoprotien).
• Assessment of fetal well-being (amniotic fluid index).
• Assessment of fetal lung maturity (L/S ratio).
• Diagnosis and follow up of labor.
• Diagnosis of PROM (ferning test).
• Diagnosis of fetal chromosomal abnormalities ( Down
syndrome, Edward syndrome, and others), and for DNA studies for
diagnosis of some single gene disorders.

12. Summary of the routine chemical tests performed on
amniotic fluid
• Tests for the Well-being and Maturity
• __________________________________________________________
• Test Normal values at term Significance
• __________________________________________________________
• Bilirubin scan 0.025 mg/dl Hemolytic disease
of the newborn
• L/S ratio 2.0 Fetal lung maturity
• Phosphatidyl- Present Fetal lung maturity
Glycerol
• Creatinine 1.3 – 4.0 mg/dl Fetal age
• Alpha fetal protein 4.0 mg/dl Neural tube disorders
• __________________________________________________________ 12

13. Amniotic fluid volume assessment
• Clinical assessment is unreliable.
• Objective assessment depends on U/S to measure:
- Deepest vertical pool (DVP).
- Amniotic fluid index (AFI). It is a total of the DVPs in each
four quadrants of the uterus. it is a more sensitive
indicator of AFV throughout pregnancy.

14. AFI

15. Amniotic fluid abnormalities
 Oligohydramnios:
Defined as reduced amniotic fluid i.e. amniotic fluid
index of 5 cm or less
or the deepest vertical pool < 2 cm.
 Polyhydramnios:
Defined as excessive amount of amniotic fluid of 2000 ml or
more
AFI of > 25 cm
or the deepest vertical pool of > 8 cm) .

17. ETIOLOGY OF POLYHYDRAMNIOS
• Idiopathic
• Fetal Anomalies
• Diabetes
• Multifetal gestation
• Immune/Non-immune hydrops
• Fetal infection
• Placental haemangiomas

18. Etiology of Polyhydramnios:
Fetal Anomalies
• Problems with swallowing and GI
absorption
• Increased transudation of fluid:
anencephaly, spina bifida
• Increased urination: anencephaly (lack of
ADH, stimulation of urination centers)
• Decreased inspiration

19. SYMPTOMS
• Dyspnea
• Abdominal pain
• Contractions  preterm labor
• Decreased Perception of Fetal
Movements

20. diagnosis of polyhydramnios
• Symptoms:
- dyspnea. • Ultrasound:
- edema. - excessive amniotic fluid.
- abdominal distention
- fetal abnormalities.
- preterm labour.
• Abdominal examination:
- ↑uterus than expected.
- difficult to palpate fetal
parts.
- difficult to hear fetal heart
sound.
- ballotable fetus.

21. (fetus)?
• Fetal prognosis worsens with more severe
hydramnios and congenital anomalies
• 15-20% fetal malformations
• Preterm delivery
• Suspect diabetes
• Prolapse of cord
• Abruption

22. (Mother)?
• Placental abruption
• Uterine dysfunction
• Post-partum hemorrhage
• Abnormal presentation -- C/S

23. TREATMENT
• Mild to Moderate hydramnios: rarely requires
treatment
• Hospitalization, bed rest
• Amniocentesis: to relieve maternal distress and to test for
fetal lung maturity. Complications: ruptured membrane,
chorioamnionitis, placental abruption, preterm labour
• Non-steroidal anti-inflammatory analgesia
• Blood sugar control

24. management
• Indomethacin therapy: .
- impairs lung liquid production/enhances absorption.
- ↓fluid movement across fetal membranes.
* complications: premature closure of ductus arteriosus,
impairment of renal function, and cerebral
vasoconstriction. So not used after 34 weeks

25. OLIGOHYDRAMNIOS

27. AETIOLOGY
FETAL
• PROM (50%)
MATERNAL
• PREECLAMPSIA
• CHROMOSOMAL ANOMALIES
• CHRONIC HT
• CONGENITAL ANOMALIES
• IUGR
• IUFD
• POSTTERM PREGNANCY DRUGS
• PG SYNTHETASE
INHIBITORS
PLACENTAL
• ACE INHIBITORS
• CHRONIC ABRUPTION
• TTTS
• CVS IDIOPATHIC
27

28. ETIOLOGY
• Postdate
• Fetal Anomalies: obstruction of fetal
urinary tract/renal agenesis
• IUGR
• ROM
• Twin/Twin transfusion
• Exposure to ACE inhibitors, and
• Non-steroidal anti-inflammatory

29. DIAGNOSIS
SYMPTOMS SIGNS
NO SPECIFIC Uterus – small for
SYMPTOMS date
Malpresentations
H/O leaking p/v
IUGR
Postterm
s/o preeclampsia
Drugs
Less fetal movements
29

30. USG
METHODS
DVP <2 cms
(<1 severe)
AFI <5 cms
(5-8 borderline)
2D pocket <15 sq cms
30

31. COMPLICATIONS
FETAL MATERNAL
Abortion
Prematurity Increased morbidity
IUFD
Prolonged labour:
Deformities –contractures
uterine inertia
Potters syndrome
pulmonary hypoplasia Increased operative
Malpresentations intervention
(malformations,
Fetal distress
distres)
Low APGAR
31

32. MANAGEMENT
DEPENDS UPON
• AETIOLOGY
• GESTATIONAL AGE
• SEVERITY
• FETAL STATUS & WELL BEING
32

33. DETERMINE AETIOLOGY
• R/O PROM
• TARGETED USG FOR ANOMALIES
• R/O IUGR ,IUFD when suspected
• Amniocentesis if chromosomal anomalies
suspected – early symmetric IUGR
33

34. TREATMENT
• ADEQUATE REST – decreases dehydration
• HYDRATION – Oral/IV Hypotonic fluids(2 Lit/d)
temperory increase
helpful during labour,prior
to ECV, USG
• SERIAL USG – Monitor growth,AFI,BPP
• INDUCTION OF LABOUR/ LSCS
Lung maturity attained
Lethal malformation
Fetal jeopardy
Sev IUGR
Severe oligo
34

35. • AMNIOINFUSION
Decreases cord
compression
Dilutes meconium
35

36. TREATMENT ACC. TO CAUSE
• Drug induced – OMIT DRUG
• PROM – INDUCTION
• PPROM – Antibiotics,steroid – Induction
• FETAL SURGERY
VESICO AMNIOTIC SHUNT-PUV
Laser photocoagulation for TTTS
36

38. Amniocentesis
• Amniocentesis is the
removal of a small
amount of amniotic fluid
from the sac around the
baby.
• This is usually performed
at 16 weeks in
pregnancy.
• A fine needle is inserted
under ultrasound
guidance through the
mothers' abdomen into a
pool of amniotic fluid.

39. Amniocentesis

40. Amniocentesis
Studies of the cells obtained from the amniotic fluid permit:
1- Chromosomal analysis of the cells which can be performed to investigate the
following;
 Diagnosis of sex of the fetus
 Detection of chromosomal abnormalities e.g. trisomy 21 (Down’s syndrome)
 DNA studies
2- The cells may indicate genetically transmitted diseases( Inherited disorders e.g
Cystic Fibrosis).
3-To check for developmental problems e.g. Spina Bifida .
4- Other studies can be done directly on the amniotic fluid including measurement of
alpha-fetoprotein where high levels of alpha-fetoproteins in the amniotic fluid
indicate the presence of a severe neural tube defect whereas low levels of alpha-
fetoproteins may indicate chromosomal abnormalities .

41. Amniocentesis
Who is the proper candidate for an Amniocentesis
investigation?
1-Those whom are suspected to have possible problems indicated
by certain tests conducted previously,(e.g If pregnancy is
complicated by a condition such as Rh-incombatibility,the
doctor can use amniocentesis to find out if the baby's lungs are
developed enough to endure an early delivery).
2- Family history of genetic abnormalities (in this case would be
advisable to seek genetic counseling before becoming
pregnant)
3-Those that have been exposed to certain risk enviromental
factors that might lead to fetal abnormalities .

43. Amniocentesis
What are the risks of amniocentesis?
• - Abortion: about 1 in 200 to 400 women aborted (higher risk if
done in the first quarter)
• - Uterine infection: 1 in 1000