(Art by Shinichi Maruyama)
In the fourth month of pregnancy, the fetus opens to the essence of the element of water. This element constitutes the pool of genetic inheritance, including the "unconsious reservoir of intuitive intelligence, will, and life-force energy". It relates to the "divine love, power, and spirit" that is ancestrally available to the fetus.
In the fourth month of pregnancy, the connective tissue develops, the matrix by which everything is connected in this new being. It is the matrix of "intercellular communication," and can be thought of as the scaffold of the astral body.
Acupuncture during this stage of development can be particularly beneficial to the pregnant woman.
(Primary source:
Sui Dynasty Imperial Physician Chao Yuan Fang as written in Energetic Anatomy and Physiology (Chinese Medical Qigong Therapy, Volume 1) by Jerry Alan Johnson)