In Neidan internal alchemy prenatal Jing is called Yuan Jing
When the spark of Yang gives birth to the original consciousness of Yuan Shen, it is establishing the deepest and most formative aspect of your inner self. This is the basis for the development of sentient life and the core of your inner Xing or ‘nature’. This is the blueprint for existence and the last aspect of our inner energetic substance that we must contact in order to move into union with the divine entity of Dao. As Yuan Shen begins to move through the realm of spirit, it transforms into the life-bringing Yuan Xi – original breath. This is the congenital manifestation of Qi when it is too high a frequency to be considered a form of energy. This is the breath that animates every aspect of your being and the breath that we seek to temporarily still in order to enter into the profound state of Wuji, the doorway of the mysterious pass. As Yuan Xi grows still once more, it forms Yuan Jing, which is the congenital aspect of original physicality. Yuan Jing sits on the threshold between the congenital and the acquired realms; from here it condenses more until it forms acquired Jing. This is the essence that enters the realm of our body via the Ming Men area between our Kidneys.
The role of the congenital three treasures is to ensure that the potential for life is there, whereas the acquired treasures function to ensure that life moves through the various developmental processes that take us from birth to death. When understanding why we must build a foundation in the acquired stages, first we should understand this key difference in the congenital and acquired treasures roles. Building a foundation in control of the acquired treasures enables us to slow the process of decline by regulating their functions. This helps to establish the foundation of good health, which we then build upon with Nei Dan training.
From the field description it seems to work on both pre-natal and post-natal?
and when I click on it, it says delivered 
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