The following abstract is reprinted from the October 1968 issue of Braces Today, the newsletter of the Pope Foundation, Inc.

Congenital Defects And Fat Solvents

Congenital absence or defective development (agenesis) of the sacrum in human babies may be related to close maternal contact with some organic solvent during pregnancy (xylene, trichloroacetylene, methylchloride acetone, and eptrol). Reporting in the Journal of Pediatrics (72:857, 1968) a Czech doctor describes results of his investigations of 9 cases of sacral agenesis occurring in Czechoslovakia between 1959 and 1966.

He found that in 5 of these 9 cases, the mother had been exposed to fat solvents of one kind or another. He also found that results of experiments with chick embryos tended to support the hypothesis of fetal injury, resulting in faulty development of the sacrum in human beings. The author, Jiri Kucera, M.D., submits his preliminary report in hopes of stimulating interest in the problem, especially in those countries where many women work in industries using organic solvents.

The affected offspring in this series consisted of 6 males and 3 females. Only 2 of the children lived; 4 died shortly after birth; 2 were still born; and 1 died three weeks after birth. All, in addition to various other defects, showed agenesis of the sacrum.

Of the 5 women exposed to organic solvent chemicals, one was constantly in contact with acetone and trichlor-ethylene; one had been in contact with tanning agents and organic solvents; one had been exposed to vapors of methylchloride and ammonia; one had been heavily exposed to xylene daily between the third and sixteenth weeks of pregnancy; and a fifth was in constant contact with acetone and petrol. This fifth woman also had a history of diabetes since she was thirteen years old. The author mentions the diabetes, since a higher incidence of sacral agenesis is reported in the offspring of diabetic women than in the general population.

Of the other 4 mothers, one had contact with German measles (rubella) after the organogenetic period only; one had had diabetes since she was ten years old; and one had been in contact with aniline dyes. In only one of the mothers, so far as could be determined, there was no complicating factor during pregnancy.

In the experimental work, 317 chick embryos were used. These were divided into 3 groups to approximate the stages of human embryonic development from the sixteenth to the twenty-fourth day of development. The embryos were exposed to a xylene atmosphere for periods of one, two, three, and four hours. The frequency of abnormalities was positively correlated with the duration of exposure but negatively correlated with the age of the embryo. Nearly half of the malformed chick specimens were rumpless. This apparently was induced by an abnormal developmental mechanism similar to the syndrome of caudal regression in human beings.