According to Takeo MATSUMURA (1884 - 1969), it was taboo to see a woman give birth in the form of her original province, because it reflected the folkways in which the period of monoimi (avoiding something regarding as ominous) when the woman worshiped a god from a different tribe from the god of the husband was jugon (purifying misfortune with charms) for the husband, and social sanction was imposed when this was violated.
松村武雄（1884-1969）によれば、女が本国人の姿で出産し、これを見ることが禁忌であるのは女が夫の神と異なる部族の神を祀る物忌みの期間が夫にとって呪禁であり、これを犯せば社会的制裁を受けるという習俗の反映である。