Amniotic Fluid

Question 1

Sources

Answer 1

T1 transudate across fetal mem and mat plasma across decidua
T2 fetal urine at 12-18wks
T3 lung fluid 350ml+ urine

Resorption by swallowing upto 1000ml per day
At term daily cycling of total af

Hypotonic to mat and fetal plasma because of intermembrane ous transport at feto plac surface

10wks 30ml
16wks 200ml
36wks 800ml
After 40 wks declines at 8%/wk

Functions

Excess
Depletion

Question 2

Causes of polyhydramnios

Answer 2

Fetal structure abn 15% anenceph, holoproscen
Dm 20%

Swallowing issue- cl/cp
Tracheal obst or comp- chaos synd
Git tracheal.or duodenal atresia
Mediastinal masses causing shift

Cardiac causes
High op.states- ebstein anomaly, thyrotox

Renal causes - ureteropelvic junction obst
Cong infection toxo, cmv, parvo
Rh incomp
Plac chorangioma

Question 3

Causes of oligo

Answer 3

Bl renal agenesis
Multicysfic dysplastic kidneys
ARPCKD
Exp to ace inhib/arbs causing fetal hypotension-renal hypoperf- renal failure
UPI late 2-3 trim

Question 4

Oligo termination

Answer 4

36-37 completed wks