妊妇有儿到产门，竟不能下，此危急存亡之时也，人以为胞胎先破，水干不能滑利也，谁知是交骨不开之故乎！盖
产门之上，原有骨二块，两相斗合，名曰交骨。未产之前，其骨自合，若天衣之无缝；临产之际，其骨自开，如开门之
见山。妇人儿门之肉，原自斜生，皮亦横长，实可宽可窄可大可小者也。苟非交骨联系，则儿门必然大开，可以手入探
取胞胎矣。此交骨为儿门之下关，实妇人锁钥之键。此骨不闭，则肠可直下；此骨不开，则儿难降生。然而交骨之能开
能合者，气血主之也。血旺而气衰，则儿虽向下而儿门不开；气旺而血衰，则儿门可开而儿难向下，是气所以开交骨，
血所以转儿身也。欲生产之顺利，非大补气血不可。然交骨之闭甚易，而交骨之开甚难。临产交骨不开者，多由于产前
贪欲，泄精太甚，精泄则气血失生化之本，而大亏矣。气血亏则无以运润于儿门，而交骨粘滞不开矣。故欲交骨之开，
必须于补气补血之中，而加开骨之品，两相合治，自无不开之患，不必催生，而儿自迅下，母子俱无恙矣。
方用降子汤。
当归（一两） 人参（五钱） 川芎（五钱） 红花（一钱） 川牛膝（三钱） 柞木枝（一两）
水煎服。一剂儿门必响亮一声，交骨开解，而儿乃降生矣。此方用人参以补气，芎、归以补血，红花以活血，牛
膝以降下，柞木枝以开关解骨，四味同心协力所以取效如神，在用开于补之中也。然单用柞木枝亦能开骨，但不
补气与血，恐开而难合，未免有下部中风之患，不若此方之能开能合之为神妙也。至于儿未临门之时万不可先用柞
木以开其门；然用降子汤亦正无妨，以其能补气血耳。若欲单用柞木，必须候到门然后可。
眉批∶方为子已临门救急而设，若子未临门，血虚难产，宜服前送子丹，不可遽服此方。
歌括∶妊妇临产胞浆开，儿到产门不下来。
原因气血太亏甚，交骨粘带不得开。
降子须将气血培，人参川芎一两归。
红花活血牛膝降，柞木开关响如雷。
Pregnant women may have the fetus reach the birth canal but fail to deliver, which is a critical moment of life and death. People often assume that the fetal membranes rupture first, causing dryness due to depleted amniotic fluid, failing to realize that this is actually caused by the failure of the Jiaogu (pubic symphysis/pelvic bones) to open!
Above the birth canal, there are originally two pieces of bone that interlock with each other, named Jiaogu. Before childbirth, these bones naturally close together, seamless as heavenly garments; at the time of labor, these bones naturally open, like opening a door to see the mountain. The flesh of the woman's birth canal originally grows obliquely, and the skin extends horizontally, possessing the actual property of being able to widen, narrow, enlarge, or shrink. If not for the connection and constraint of the Jiaogu, the birth canal would necessarily be wide open, allowing one to insert a hand to retrieve the fetal sac. This Jiaogu serves as the lower gate of the birth canal and is essentially the key to the woman's body lock. If this bone does not close, the intestines could prolapse directly; if this bone does not open, the fetus cannot descend. However, the ability of the Jiaogu to open and close is governed by Qi and Blood. When Blood is abundant but Qi is deficient, the fetus moves downward but the birth canal does not open; when Qi is abundant but Blood is deficient, the birth canal can open but the fetus has difficulty turning downward. Thus, Qi is used to open the Jiaogu, and Blood is used to rotate the fetus's position. For smooth delivery, it is imperative to greatly tonify Qi and Blood.
However, the closing of the Jiaogu is very easy, while its opening is very difficult. Cases of Jiaogu failing to open during labor are mostly due to excessive indulgence in desires before childbirth, leading to excessive loss of essence. Loss of essence destroys the root of Qi and Blood generation, resulting in severe deficiency. Deficiency of Qi and Blood means there is insufficient energy to moisten and nourish the birth canal, causing the Jiaogu to become sticky and stuck, unable to open. Therefore, to open the Jiaogu, one must add herbs that open bones within the context of tonifying Qi and Blood. Treating both aspects together ensures no risk of failure to open; without needing催产 (induction) herbs, the fetus will descend rapidly, leaving both mother and child safe.
The prescription is Jiangzi Tang (Descend the Child Decoction).
Danggui (Radix Angelicae Sinensis, 1 liang), Renshen (Radix Ginseng, 5 qian), Chuanxiong (Rhizoma Chuanxiong, 5 qian), Honghua (Flos Carthami, 1 qian), Chuan Niuxi (Radix Achyranthis Bidentatae, 3 qian), Zuomuzhi (Ramulus Quercus variabilis, 1 liang).
Decoct in water and take orally. After one dose, the birth canal will likely make a loud sound, the Jiaogu will separate, and the child will be born. This prescription uses Renshen to tonify Qi, Chuanxiong and Danggui to tonify Blood, Honghua to invigorate Blood, Niuxi to guide blood downward, and Zuomuzhi to open the joints and separate the bones. These ingredients work in concert to achieve miraculous effects, relying on the principle of incorporating opening methods within tonification. Although using only Zuomuzhi can also open the bones, without tonifying Qi and Blood, there is a fear that the bones might open but fail to close properly, potentially leading to wind-stroke in the lower part. This is inferior to the ingenuity of this prescription, which can both open and close. Regarding the timing: when the fetus has not yet reached the birth canal, one must absolutely not use Zuomuzhi first to force the opening; however, using Jiangzi Tang is perfectly fine because it tonifies Qi and Blood. If one wishes to use only Zuomuzhi, it must be waited until the fetus reaches the birth canal before doing so.
Marginal Note: This prescription is designed for emergency rescue when the fetus has already reached the birth canal. If the fetus has not yet arrived and difficult labor is due to Blood deficiency, one should take Songzi Dan (Send Child Pill) mentioned earlier, and not rashly take this prescription.
Verse:
When pregnant women go into labor and the amniotic sac breaks,
The fetus reaches the birth canal but fails to come down.
The cause is severe deficiency of Qi and Blood,
Causing the Jiaogu to stick and preventing it from opening.
To descend the child, one must cultivate Qi and Blood,
Using Renshen, Chuanxiong, and one liang of Danggui.
Honghua invigorates Blood, Niuxi guides descent,
Zuomuzhi opens the joint with a sound like thunder.