Baby's inhaling and exhaling small amounts of amniotic fluid, which is essential for the development of his lungs. These so-called breathing movements are also good practice for when he's born and takes that first gulp of air. Thumb sucking calms the baby and strengthens the cheek and jaw muscles. Baby is probably very active in the womb, as the most active weeks are typically between weeks 24 and 28.
Information provided by 4DScan. Visit them at www.4dscan.co.za.
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