Pregnant dogs are susceptible to chloroform administered shortly before delivery or during labor, and show the same degree of liver injury as normal dogs, or even a somewhat greater one.
Chloroform anesthesia may cause more or less hyaline necrosis in the border zone between the maternal and fetal parts of the placenta that may lead to hemorrhage, placental separation, and premature delivery.
Chloroform anesthesia causes no injury to the liver of the fetus nor to any other fetal organ, in spite of the fact that it can be demonstrated to be present in these tissues.
These experiments raise objections to the use of chloroform in pregnant women where an anesthetic must be continued for half an hour or longer. Chloroform anesthesia may be admissible for the few minutes at the end of the delivery, but when operative measures are necessary, before or after delivery, it is a dangerous anesthetic and surely capable of producing injury to the liver in the manner recognized in the case of normal persons.
Objections may be raised to the application of conclusions derived from experiments on dogs to human cases; but the similarity of the effects of chloroform in man and dog surely affords a sound basis of comparison.
Two fundamental facts would seem to be now established: (1) Normal human adults may be fatally poisoned (late chloroform poisoning) by chloroform anesthesia of one half to one hour's duration. (2) Normal and pregnant dogs are equally susceptible to late chloroform poisoning, and may be fatally poisoned by an anesthesia of two hours' duration.
Hence one may conclude that probably normal and pregnant human beings are equally susceptible to chloroform poisoning, that chloroform anesthesia during any part of the pregnant period is capable of causing liver necrosis, and, consequently, that chloroform is a dangerous anesthetic.