[ozmidwifery] Fetal Lung Fluid

[Anne Clarke]

Dear All,   Here is a piece of news that will (may) knock your socks off.   Fetal lung fluid in utero is completely different than amniotic fluid.  That is, its Ph is similar to the very acidic stomach fluid.  There is no mix of amniotic fluid and lung fluid even during fetal respirations in utero.   Fetal respiration reduces and even stops prior to and during labour.  Absorpiton of the fetal lung fluid then starts to begin.   The lung fluid is not 'squeezed' out at birth, and you can tell mum's that during caesarean this is not necessary - are you all still with me! and the squeesing effect from a vaginal birth is not a necessary process for the expansion of the lungs.  This is one of the factors that babies don't drown during a waterbirth.   Absorption of the fetal lung fluid into the capillaries is vital as this process is an important part of the expansion of the capillaries of the lung so blood can flow into the blood vessels of the lung so gas exchange can occur.   The fluid is usually reabsorbed within a few hours after birth and it is the malabsorption or slow absorption of the lung fluid that is responsible for transient TTN not that lung fluid is expelled from the lung. This is why TTN is transient and babies recover after a few hours.   Regards, Anne Clarke   Johnson, P (1996) Birth under water - to breathe or not to breathe, British Journal of Obstetrics and Gynaecology, Vo. 103, pp 202-208.   Karlber, P et al (1962) alteration of the infant's thorax during vaginal delivery'. Acta Obstetrca Gynecol Scandavia. Vol.41, p 223.