Tohoku J. Exp. Med., 1966, 89

Effect of Maternal Medication during Pregnancy upon Behavioral Development of Offspring


Department of Obstetrics and Gynecology (Prof. K. Kushima), Tohoku University School of Medicine, Sendai

The present study was designed to investigate the effects of four centrally acting drugs (chlorpromazine 6.0 mg/kg, reserpine 0.1 mg/kg, meprobamate 60.0 mg/kg and phenobarbital 8.0 mg/kg) upon the behavioral development, especially development of intelligence, of the offspring of rats, to which these drugs were administered during four days of the early and late periods, from the 5th to 8th and from the 17th to 20th days, of pregnancy.

When the offsprings were 90 days old, the level of their general activity was measured by the revolving drum technique. In both the administration periods the activity level was significantly lower only in the meprobamate-treated group than that in the control group.

Intelligence of 120-day-old animals was tested by Hebb-Williams' enclosed field test. When the administration was done in the early period of gestation, the intelligence of the chlorpromazine-, meprobamate- or phenobarbital-treated groups was each significantly lower than that of the control group. But when the administration was done in the late period of pregnancy, only the meprobamatetreated group showed a significantly lower intelligence than the control group.

These findings were also supported by the results of the brain activity test by a Woodbury's electroshock apparatus.

From these results it is suggested that some of the centrally acting drugs have possibility of causing a retardation of mental development of offspring, and that the prenatal medication in the early period of gestation has a profounder effect than that in the late period.


Tohoku J. Exp. Med., 1966, 89, 265-272