Frequency of sex chromatin in the buccal smear of newborn females and their mothers during first six days after delivery.

The frequencies of sex chromatin in the buccal smear of the newborn females and their mothers were low on the first post-partum day and it increased gradually during the second and third day. By the fourth and fifth day it stabilized and the incidence of sex chromatin both in the mothers and the children became similar, although the frequency on the first day was significantly lower in the newborn. The incidences of pyknotic cells in the buccal smears of the newborns and their mothers were highest on day one and these declined rapidly in the following days. The significance of these findings have been discussed.