Oligohydramnios and Cortisone-induced Cleft Palate in the Mouse

Abstract

A HIGH frequency of congenital cleft palate has been demonstrated in mouse embryos after puncture of the amniotic sac shortly before the normal time of palate closure^1,2. The treated embryos were obviously constricted, and it was postulated that the cleft palates resulted from flexion of the neck pressing the lower jaw against the chest and thus jamming the tongue between the palatal shelves and preventing their closure. Kreshover³ confirmed these observations in rats. Further experiments demonstrated that cleft palate occurred if the embryos were freed from the uterus after withdrawal of amniotic fluid, but did not occur in such embryos if no fluid was removed⁴. Embryos observed at the normal time of palate closure after puncture of the amniotic sac do indeed have their lower jaws compressed and their tongues placed unduly high in the space between the shelves (unpublished work of Humphreys, Rosenbaum and Fraser), and it seems clear that in these circumstances cleft palate does result from the oligohydramnios.