1. FETAL MEMBRANES

2. UMBILICAL CORD Initially connecting stalk Blood vessels develop
Normally 2 arteries, 1 vein
Doppler Velocimetry
With folding shifts ventrally
LENGTH: 30-90cm (average 55cm)
Abnormally long- prolapse
Abnormally short- premature separation

4. Covered by Amnion Knots
False- length of blood vessels more than umbilical cord
True- head passes through loop of cord, dangerous

8. Amnion Initially located cranially Oval attachment
Cavity expands, obliterates chorionic cavity, lining of umbilical cord

11. AMNIOTIC FLUID Plays major role in fetal growth and development
SOURCES
Initially secreted by amniotic cells
Maternal tissue, diffusion across amniochorionic membrane
Diffusion through chorionic plate, from intervillous space

12. FETAL
Before keratinization, fetal interstitial tissue
After that; fetal respiratory tract ( ml/ day)
GIT
By 11th week: fetal excretory system (500ml/day)
Volume normally increases slowly
30ml- 10 weeks
350ml- 20 weeks
ml– 37 weeks

14. COMPOSITION Aqueous solution with suspended materials Epithelial cells
Organic: proteins, enzymes, hormones, pigments, carbohydrates
Inorganic:salts

15. AMNIOCENTESIS AMNIOTIC FLUID EXAMINATION
Fetal proteins, hormones, enzymes can be studied
Fetal cells; chromosomal abnormalities
Alpha fetoproteins:
High- NTD
Low- Trisomy etc

16. SIGNIFICANCE Embryo floats, moves freely Cushioning effect
Barrier to infections
Symmetrical growth of fetus
Muscular development
Normal fetal lung development
Prevents adherence of amnion to embryo
Controls body temperature
Maintains homeostasis

17. ABNORMALITIES OLIGOHYDROAMNIOS Causes Complications Renal agenesis
Obstructive uropathy
Complications
Pulmonary hypoplasia
Facial defects
Limb defects

19. POLYHYDROAMNIOS Causes Complications Idiopathic Anencephaly
Esophagial atresia
Complications
Premature onset of labour

20. YOLK SAC (UMBILICAL VESICLE)

21. SIGNIFICANCE Transfer of neutrients Blood vessels development
Endoderm- epithelium of gut, trachea, lungs
PGCs

22. Allontois

23. MULTIPLE GESTATION DIZYGOTIC: 2/3rd 7-11/10,000 births
Simultaneous shedding of two ova, fertilization by two sperms
Different genetic make up
Resemblance like other siblings

24. Implant individually
Each develop own placenta, amnion, chorionic sacs

25. If placents lie closely, may fuse
ERYTHEROCYTE MOSAICISM

27. MONOZYGOTIC TWINS Single ovum is fertilized 3-4/10,000 births
From splitting of ovum at different stages of development
Earliest at two cell stage
Implant separately, separate placentae etc
Resemble dizygotic but same genetic constitution

29. At early Blastocyst stage
Inner cell mass splits into two within same blastocyst cavity
Common placenta, chorionic cavity
Separate amniotic cavity
At bilaminar germ disc
Before the appearance of primittive streak
Common placentae, amnion, chorionic cavity
Usually blood supply is well balanced
May be unbalanced
Risks are more (one fetus may die)

31. TWIN TWIN TRANSFUSION SYNDROME
Shunting of arterial blood from one fetus to venous circulation of other. Donor is small, pale, anemic while recipient is large and polycythemic
FETUS PAPYRACEUS
VANISHING TWIN

34. INCOMPLETE SEPARATION
CONJOINED TWINS
(Siamese)
Craniopagus
Thoracopagus
pyopagus