许学士曰∶妇人妊娠，唯在抑阳助阴。然胎前药，最恶群队。若阴阳交错，别生他病。唯南山道士枳壳散，
所以抑阳。四物汤，所以助阴。但枳壳散少寒，单服之，恐有胎寒腹痛之患。以内补丸佐之，则阳不至强，阴
不至弱，阴阳调而胎孕安。此前人未尝论及也。
娄全善曰∶观许学士论枳壳、四物、内补三方，人皆用之，何如？大率妊妇唯在抑阳助阴。经云∶阴搏阳
别，谓之有子。盖关前为阳，关后为阴，尺中之脉，按之搏手不绝者，妊也。妇人平居，阳气微盛，无他病。
及妊子，则经闭以养胎。若阳气盛搏之，则经脉妄行，胎始不固，故贵抑阳助阴。但枳壳散少寒，内补丸佐之，
则阴阳调和，而胎气自安矣。
朱丹溪曰∶世之难产者，往往见于郁闷安佚之人，富贵豢养之家。若贫贱辛苦者，无有也。方书止有瘦胎
饮一论，其方为湖阳公主设也，实非极至之言。彼湖阳公主，奉养太过，其气必实，耗其气，使之和平，故易
产。此南山道士进瘦胎、枳壳散，抑阳降气，为众方之冠，温隐居加木香、当归佐之。若形肥人，知其气必虚，
久坐知其气不运，而气愈弱，儿在胞胎，因母气不能自运，故难
产。当补其母之气，则儿健易产矣。遂于《大全方》紫苏饮，加参、术补气药，随母形色禀性，参时加减，名曰
达生散，人参、白术、白芍、当归、腹皮、紫苏、陈皮、甘草，加枳壳、砂仁。
慎斋按∶以上五条，序胎前用方之大略也。胎前用药，清热养血为主。而清热养血之后，唯以补脾为要，
此培后天元气之本也。若养葵则不用芩、术，而以地黄饮加杜、续以补肾。夫胎系于肾，肾固则胎自安，此补
脾不如补肾之要妙也。许学士内补丸已启其端，赵氏从而发明之，可谓扶安胎之秘旨矣。
Xu Xueshi stated: In women during pregnancy, the key lies in suppressing Yang and assisting Yin. However, for medications used during pregnancy, it is most undesirable to have a chaotic mixture of herbs. If Yin and Yang energies become intermixed and disordered, other diseases may arise. The Zhiqiao San (Bitter Orange Powder) by the Daoist of Nanshan Mountain is used to suppress Yang; the Siwu Tang (Four Substances Decoction) is used to assist Yin. However, Zhiqiao San has a slightly cold nature, and taking it alone may cause the risk of fetal coldness and abdominal pain. By using Neibu Wan (Internal Supplement Pill) as an adjuvant, Yang will not become excessive, and Yin will not become deficient; when Yin and Yang are harmonized, the pregnancy will be secure. This is a point not previously discussed by earlier scholars.
Lou Quanshan said: Regarding Xu Xueshi’s discussion on the three formulas—Zhiqiao San, Siwu Tang, and Neibu Wan—and their widespread use, what is your opinion? Generally, for pregnant women, the principle is to suppress Yang and assist Yin. The Classics state: "When the Yin pulse beats distinctly separate from the Yang, it indicates pregnancy." Roughly speaking, the area before the cun position belongs to Yang, and the area after belongs to Yin. If the pulse at the chi position feels vigorous and unceasing upon pressure, it indicates pregnancy. When a woman is not pregnant, her Yang energy is slightly abundant, and she suffers no other illness. Once pregnant, menstruation ceases to nourish the fetus. If Yang energy becomes excessively strong and clashes with the meridians, it causes erratic flow in the vessels, making the fetus unstable. Therefore, it is crucial to suppress Yang and assist Yin. Since Zhiqiao San is slightly cold, using Neibu Wan as an adjuvant harmonizes Yin and Yang, thereby stabilizing the fetal qi naturally.
Zhu Danxi stated: Difficult labor often occurs in individuals who are prone to depression and live in ease, typically those raised in wealthy families. It rarely happens among the poor and hardworking. Medical texts only contain one discussion on Shoutai Yin (Fetus-Thinning Drink), which was formulated for Princess Huyang. It is not, however, the ultimate truth. Princess Huyang received excessive nourishment, so her constitution was likely excess and robust; consuming her Qi to restore balance made childbirth easier. The Daoist of Nanshan Mountain presented Shoutai Yin and Zhiqiao San to suppress Yang and descend Qi, ranking them among the best formulas. Wuyin Jushi added Muxiang (Aucklandiae Radix) and Danggui (Angelicae Sinensis Radix) to assist them. For obese individuals, we know their Qi is likely deficient; prolonged sitting indicates stagnant Qi movement, leading to further weakness. The fetus, residing in the womb, relies on the mother's Qi for movement; if the mother's Qi cannot function autonomously, difficult labor ensues. One should tonify the mother's Qi so that the fetus becomes strong and delivery is facilitated. Thus, I modified the Zisu Yin (Perilla Leaf Decoction) from *Daquan Fang* by adding Qibi (Qi-tonifying) herbs such as Renshen (Ginseng Radix et Rhizoma) and Baizhu (Atractylodis Macrocephalae Rhizoma). Adjusted according to the mother's physique and constitutional type, it was named Dasheng San (Reaching Life Powder). Its ingredients include Renshen, Baizhu, Baishao (Paeoniae Radix Alba), Danggui, Fupi (Citri Reticulatae Pericarpium), Zisu (Perillae Folium), Chenpi (Tangerine Peel), Gancao (Licorice Root), along with Zhiqiao and Sharen (Amomi Fructus Rotundus).
Shenzhai commented: The above five points outline the general principles of prescribing during pregnancy. Medications for pregnancy primarily focus on clearing heat and nourishing blood. After clearing heat and nourishing blood, the most critical step is tonifying the Spleen, which is the foundation of cultivating postnatal Yuan Qi (Original Energy). In cases like Yangkui, Huangqin (Scutellariae Radix) and Baizhu are not used; instead, Dihuang Yin (Rehmannia Decoction) is combined with Duzhong (Eucommiae Cortex) and Xuduan (Dipsaci Radix) to tonify the Kidney. The fetus is anchored by the Kidney; if the Kidney is solid, the fetus remains secure. This reveals the subtle superiority of tonifying the Kidney over tonifying the Spleen in certain contexts. Xu Xueshi’s Neibu Wan initiated this line of thought, which Zhao Shi further elucidated, truly uncovering the secret principles of supporting fetal security.