张景岳曰∶以左右分阴阳，则左为阳右为阴。以尺寸分阴阳，则寸为阳尺为阴。以脉体分阴阳，则鼓搏沉
实为阳，虚弱浮涩为阴。诸阳实者为男，诸阴虚者为女，庶为一定之论。
娄全善曰∶按丹溪云∶男受胎在左子宫，女受胎在右子宫。推之于脉，其义亦然。如胎在左，则气血护胎
而盛于左，故脉亦从之而左疾，为男。左大为男也。胎在右，则气血护胎而盛于右，故脉亦从之而右疾，为女。
右大为女也。亦犹经云∶阴搏阳别，谓之有子。言受胎处，脐腹之下，气血护胎，而盛于下。故阴之尺脉，鼓
搏有力，与阳之寸脉殊别也。
慎斋按∶《难经》云，肾有两，左为肾，
右为命门。命门，男子藏精，女子系胞。则知命门即胞门，而子宫属焉。肾有左右之分，而子宫无左右之分。
今丹溪云，男受胎在左子宫。女受胎在右子宫，是妇人胞门有两子宫矣。甚为凿空无据。今全善以丹溪之言为
证，但云气血护胎而盛于左，则为男；气血护胎而盛于右，则为女，乃可。若云盛于左子宫为男，盛于右子宫
为女，犹为附会之谬。假如妇人有品胎骈胎，则子宫亦有累累耶。
潘硕甫曰∶《举要》云∶男女之别，以左右取。左疾为男，右疾为女。沉实在左，浮大在右，左男右女，可
以预剖。盖左脉疾胜于右，是为男孕。以男属阳居左，胎气盅于阳，故左胜。右脉疾胜于左，是为女孕。以
女属阴居右，胎气盅于阴，故右胜也。又更视其腹如箕为女胎，腹如釜为男胎。盖男女孕于胞中，女面母腹，
则足膝抵腹，下大上小，故如箕。男面背母，则背脊抵腹，其形正员，故如釜也。又胎有男女，则成有迟速。
男动在三月，阳性早也。女动在五月，阴性迟也。
Zhang Jingyue stated: To distinguish Yin and Yang by left and right, the left is Yang and the right is Yin. To distinguish Yin and Yang by Cun (Inch) and Chi (Cubit) positions, the Cun position is Yang and the Chi position is Yin. To distinguish Yin and Yang by pulse body/quality, vigorous beating and deep-solid qualities are Yang, while weak and floating-choppy qualities are Yin. Generally, those with abundant Yang Qi are male, and those with deficient Yin Qi are female; this can be considered a fixed principle.
Lou Quanshan stated: According to Zhu Danxi: Male conception occurs in the left uterus, and female conception occurs in the right uterus. Extending this logic to pulse diagnosis, the principle remains the same. If the fetal Qi is on the left, then Blood and Qi protect the fetus and become abundant on the left, so the pulse also follows this trend and beats rapidly on the left, indicating a male. A larger pulse on the left indicates a male. If the fetal Qi is on the right, then Blood and Qi protect the fetus and become abundant on the right, so the pulse also follows this trend and beats rapidly on the right, indicating a female. A larger pulse on the right indicates a female. This is also consistent with the Classic saying: "When the Yin pulse beats vigorously and differs from the Yang pulse, it signifies pregnancy." This means that at the site of conception, below the umbilicus and abdomen, Blood and Qi protect the fetus and become abundant in the lower part. Therefore, the Chi pulse of the Yin position beats vigorously and distinctly differs from the Cun pulse of the Yang position.
Shen Zhai commented: The *Nan Jing* (Classic of Difficult Issues) states that there are two kidneys: the left is the Kidney, and the right is the Mingmen (Gate of Life). The Mingmen stores Essence in men and connects to the Bao Palace (uterus) in women. From this, we know that the Mingmen is the Bao Men (gate of the womb), and the uterus belongs to it. The Kidneys have left and right distinctions, but the uterus does not have left and right distinctions. Now, Zhu Danxi says that male conception occurs in the left uterus and female conception in the right uterus, implying that a woman's Bao Men has two uteruses. This is highly arbitrary and baseless. Now, Lou Quanshan uses Zhu Danxi's words as evidence, stating only that if Blood and Qi protect the fetus and become abundant on the left, it is male; if they become abundant on the right, it is female. This is acceptable. However, to say that abundance in the left uterus indicates a male and abundance in the right uterus indicates a female is still an forced and erroneous interpretation. For instance, if a woman carries multiple fetuses or conjoined twins, would she have numerous uteruses?
Pan Shuofu stated: The *Ju Yao* (Summary of Essentials) says: The distinction between male and female is determined by the left and right pulses. A rapid pulse on the left indicates a male, and a rapid pulse on the right indicates a female. Deep and solid on the left, floating and large on the right; left for male, right for female, allowing for prediction. Generally, if the left pulse is more rapid than the right, it indicates a male pregnancy. Since males belong to Yang and reside on the left, fetal Qi fills the Yang aspect, so the left prevails. If the right pulse is more rapid than the left, it indicates a female pregnancy. Since females belong to Yin and reside on the right, fetal Qi fills the Yin aspect, so the right prevails. Furthermore, observe the shape of the abdomen: if it is like a winnowing basket, it is a female fetus; if it is like a cauldron, it is a male fetus. Generally, when male and female fetuses develop in the Bao Palace, a female fetus faces the mother's abdomen, so its feet and knees press against the abdominal wall, making it wider at the bottom and narrower at the top, thus resembling a winnowing basket. A male fetus faces away from the mother's back, so its spine presses against the abdominal wall, making its shape perfectly round, thus resembling a cauldron. Additionally, regarding the timing of formation: male fetuses move at three months because Yang energy emerges early. Female fetuses move at five months because Yin energy arrives late.