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。
孕妇胎儿已到达产门，却无法娩出，这是生死攸关的危急时刻。人们以为是胎膜先破裂，羊水枯竭导致产道干涩不滑利，却不知这是因为交骨（骨盆耻骨联合）未能打开的缘故！
原来在产门之上，原本有两块骨头，左右相互扣合，称为交骨。在未分娩之前，这两块骨头自然闭合，如同天衣无缝一般；到了临产之际，这两块骨头自然张开，就像开门见到山景一样。妇人产道的肌肉原本就是斜向生长的，皮肤也是横向延展的，实际上具有可宽可窄、可大可小的弹性。如果不是因为交骨的连接约束，那么产门必然已经大开，甚至可以用手进去探取胎胞了。这交骨是产门的下关隘，实际上是妇人身体的锁钥关键。如果这骨头不闭合，肠子就会直接脱出；如果这骨头不打开，胎儿就难以降生。然而，交骨之所以能够开合，是由气血来主导的。血旺而气衰时，胎儿虽然向下移动但产门打不开；气旺而血衰时，产门可以打开但胎儿难以向下转动，这就是气用来打开交骨，血用来转动胎儿身位的道理。想要生产顺利，非大补气血不可。
然而，交骨闭合很容易，而交骨打开却很困难。临产时交骨不开的，大多是因为产前贪恋欲望，泄精太过，精气泄漏则失去了气血化生的根本，导致气血大亏。气血亏损就无法运化滋润于产门，导致交骨粘连滞涩无法打开。所以想要交骨打开，必须在补气补血之中，加入开骨的药物，两者结合治疗，自然没有打不开的隐患，不必使用催产药，胎儿自然会迅速降生，母子都平安无恙。
方剂用降子汤。
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。服用一剂后，产门必定会响亮地发出一声，交骨解开，胎儿于是降生。此方用人参来补气，川芎、当归来补血，红花来活血，牛膝来引血下行，柞木枝来开关解骨，这几味药同心协力，所以取得神效，关键在于在补益之中运用开通之法。然而单用柞木枝也能开骨，但不补气与血，恐怕打开后难以闭合，未免有下部中风的风险，不如此方能开能合的神妙之处。至于胎儿尚未到达产门之时，万万不可先用柞木枝来打开产门；然而使用降子汤也没有妨碍，因为它能补益气血。如果想要单用柞木枝，必须等到胎儿到达产门之后才可以。
眉批：此方是为胎儿已经到达产门时的急救而设，如果胎儿尚未到达产门，因血虚导致的难产，适宜服用前文的送子丹，不可仓促服用此方。
歌诀：
孕妇临产胎膜破裂羊水流出，胎儿已到产门却不下来。
原因是气血亏损过于严重，交骨粘连牵制无法打开。
降生胎儿须要培补气血，人参川芎配合一两当归。
红花活血牛膝引血下行，柞木枝开关响声如雷。
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.