《病源论》云∶阴搏阳别谓之有子者，此是气血和调，阳施阴化也。诊其手少阴脉动甚
者，妊子也。尺中之脉，按之不绝者，妊娠也。
《产经》云∶凡妇人三部脉，浮沉正等者，此谓有子也。（今按∶《八十一难》云∶从掌
后三寸为三部，则寸与关尺各得之寸一。凡诊脉者，先明三部九候。）
《短剧方》云∶凡妇人虚羸，血气不足，肾气少弱；或当风取冷大过，心下有痰水者，
欲有胎，便喜病阻。何谓欲有胎，其人月水尚来，颜色肌肤如常而沉重愦闷。不用饮食，不
知其患所在，脉理顺时平和。则是欲有胎也。如此经二月日后，便觉不通，即结胎也。（《玉
房秘诀》云∶初施泻妇阴 阳有力如吮者，是有子之候也。）
《太素经》云∶玄元皇帝曰∶人受天地之气，变化而生，一月而高（膏），二月而脉，
三月而胞，四月而胎，五月而脉筋，六月而骨，七月而成形，八月而动，九月而臊，十月而
生。
《周书》云∶人感十而生，天五行，地五行，合为十也。天五行为五常，地五行为五脏，
故《易》曰∶在天成象，在地成形者也。
《家语》云∶天一，地二，人三，三三而九，九九八十一，一主日，日数十，故十月生。
《玉房秘诀》云∶阳精多则生男，阴精多则生女，阳精为骨，阴精为肉。
《诸病源候论》说：阴脉搏动有力而与阳脉有所区别，称为怀孕，这是气血调和、阳气施布、阴气化育的结果。诊察手少阴心经的脉象，如果搏动明显剧烈，是怀孕的征象。尺部脉象，重按而不绝止的，是妊娠的表现。
《产经》说：凡是妇女寸、关、尺三部脉象，浮取和沉取的力度相当，这叫做怀孕。（现在考证：《难经·八十一难》说：从掌后高骨向后三寸分为三部，那么寸、关、尺各得一寸长。凡是诊脉的人，必须先明白三部九候的道理。）
《短剧方》说：凡是妇女身体虚弱消瘦，血气不足，肾气少而衰弱；或者因为贪凉受风过度，导致心下有痰饮停聚的人，想要受孕时，就容易发生疾病阻滞。什么叫想要受孕？其人月经尚且正常来潮，面色肌肤如常，但感到身体沉重、心中烦闷。不想饮食，不知道病痛所在，脉象理顺时平和。这就是想要受孕的状态。像这样经过两个月后，月经便停止不通，这就形成了胎孕。（《玉房秘诀》说：初次交合射精时，若妇人阴道收缩有力，如同吮吸一般，是有怀孕的征兆。）
《太素经》记载：玄元皇帝（指老子）说：人禀受天地之气，变化而生。一个月时胚胎初成（膏），二个月时脉络形成，三个月时胞宫确立，四个月时胎儿成形，五个月时筋脉生长，六个月时骨骼生成，七个月时形体完备，八个月时胎动，九个月时毛发长成（臊指体毛），十个月时出生。
《周书》说：人感天地之数而生，天有五行，地有五行，合为十数。天的五行对应五常，地的五行对应五脏，所以《易经》说：在天形成天象，在地形成地形。
《孔子家语》说：天一，地二，人三，三三得九，九九八十一，一主一日，日数十（指十月怀胎约三百日），所以十月分娩。
《玉房秘诀》说：阳精多则生男孩，阴精多则生女孩，阳精构成骨骼，阴精构成肌肉。
The *Zhubing Yuanhou Lun* (Treatise on the Pathogenesis and Manifestations of All Diseases) states: "When the Yin pulse beats vigorously and differs from the Yang pulse, it is called pregnancy. This indicates that Qi and Blood are harmonized, Yang energy is disseminated, and Yin essence is transformed." When palpating the pulse of the Hand-Shaoyin Heart Meridian, if the pulsation is markedly vigorous, it indicates conception. If the Chi (Cun-Kuan-Chi) pulse remains unceasing upon deep pressure, it indicates pregnancy.
The *Chan Jing* (Classic of Childbirth) states: "In women, when the pulses at the three positions (Cun, Guan, Chi) are equal in depth and force during both superficial and deep palpation, this is termed pregnancy." (Current commentary: The *Nan Jing* [Classic of Difficult Issues], Chapter 81, states: 'Three cun distal to the radial styloid process constitute the three positions; thus, each of the Cun, Guan, and Chi positions spans one cun.' Physicians must first understand the principle of the Three Positions and Nine Palpations.)
The *Duan Ju Fang* (Short Formulas) states: "In women who are weak and emaciated, deficient in Qi and Blood, with weak Kidney Qi; or those who have excessively exposed themselves to wind and cold, resulting in phlegm-fluid retention in the epigastrium, when they desire conception, they may easily experience obstruction and illness. What does 'desiring conception' mean? The menstruation still arrives regularly, complexion and skin appear normal, yet the person feels heavy and mentally confused. There is a lack of appetite, the location of the ailment is unknown, and the pulse appears smooth and peaceful when regulated. This indicates a state of desiring conception. After two months from such a state, menstruation ceases, indicating that the fetus has formed." (The *Yufang Mijue* [Secrets of the Jade Chamber] states: "If upon initial ejaculation, the woman's vagina contracts powerfully as if sucking, this is a sign of conception.")
The *Tai Su Jing* (Grand Simplicity Classic) records: "The Xuan Yuan Emperor (Laozi) said: Humans are born through change by receiving the Qi of Heaven and Earth. In the first month, the embryo forms (gao); in the second month, vessels develop; in the third month, the uterus is established; in the fourth month, the fetus takes shape; in the fifth month, sinews grow; in the sixth month, bones form; in the seventh month, the form is complete; in the eighth month, fetal movement occurs; in the ninth month, hair grows (sao refers to body hair); and in the tenth month, birth occurs."
The *Zhou Shu* (Book of Zhou) states: "Humans are generated by the number ten. Heaven has Five Elements, Earth has Five Elements, combining to make ten. The Five Elements of Heaven correspond to the Five Constants, and the Five Elements of Earth correspond to the Five Zang Organs. Thus, the *I Ching* [Book of Changes] says: 'Heaven manifests images, Earth manifests forms.'"
The *Kongzi Jiayu* (Family Sayings of Confucius) states: "One is Heaven, Two is Earth, Three is Humanity. Three times three makes nine; nine times nine makes eighty-one. One governs the day. Since there are roughly thirty days in a lunar month, ten months result in birth."
The *Yufang Mijue* (Secrets of the Jade Chamber) states: "Abundant Yang essence produces a male; abundant Yin essence produces a female. Yang essence constitutes bone, and Yin essence constitutes flesh."