After 20 weeks of gestation main contribution of amniotic fluid is by:

Ans: a (Fetal urine) Ref: Dutta, 6th ed, p. 37After 20 weeks of gestation the main contribution of amniotic fluid is by fetal urine. The fetal daily urine output at term is about 400-1200 ml.Theories on origin of amniotic fliud1. Asa transudate from maternal serum2. As a transudate across umbilical cord or from the fetal circulation in the placenta or secretion from amniotic epithelium3. Transudate of fetal plasma through fetal skin4. Fetal urineVolume50 ml at 12 wks400 ml at 20 wks1000 ml at 36-38 wks800 ml at termAbnormal colors of amniotic fluid1. Green- meconium stained, seen in fetal distress2. Golden colour- Rh incompatibility3. Saffron- post maturity4. Dark colour- concealed accidental hemorrhage5. Dark brown (tobacco j uice)-IUD