Resorption, fetal

The biological activity of various vitamin E forms was estabUshed by the fetal resorption assay ia tats and is assumed to be appHcable to humans. The results of some human studies may iadicate that the ratio of 1.36 underestimates the biological activity of the RRR form relative to the all-rac form of a-tocopheryl acetate (10—12). 

Teratogenicity. The effects of chlorodibenzodioxins on maternal and fetal body measurements, incidence of fetal resorptions, and anomalies are given in Tables III and IV. 

Dibenzo-/F-dioxins on Maternal and Fetal Body Incidence of Fetal Resorptions... 

OCDD. Signs of maternal toxicity were not observed in rats given 100 or 500 mg/kg/day OCDD. Examination of the fetuses did not reveal changes in fetal body measurements, incidence of fetal resorptions, or incidence of any fetal anomaly among litters or the fetal population. At 500 mg/kg/day, the incidence of subcutaneous edema was significantly increased among the fetal population (23/100 compared with 8/156 in controls) but not among litters (9/18 compared with 6/28 in controls). 

PCB diets were associated with reproductive impairment including anovulation, fetal resorption, delayed ovulation, increased gestation, and decreased litter size. Hepatic estrogen binding site concentrations decreased with increasing dietary PCB concentrations but not uterine estrogen receptor sites... 

Reproductive Rat Gd 7-17 (Wistar) (GO) 167 500 (increased late-stage fetal resorptions) Shimizu et al. 1992... 

Rat (Sprague- Dawiey) 11d Gd6-16 (GO) 100 F 500 F (increased fetal resorptions reduced gestation indices, quantitative data not provided) Weeks etal. 1979... 

Another fat-soluble vitamin, E, was found by Evans and Bishop in 1923. Pregnant rats on a defined diet (alcohol-extracted casein, cornstarch, and lard) supplemented with butter (vitamins A and D) and yeast extract (vitamin B group) produced few young because of fetal resorption. Male rats on the same diet were sterile. The disorders, which have not been identified in man, were corrected by wheat-germ oil, from which tocopherol, the active ingredient, was isolated in 1936. In spite of intensive investigations and a recognition that the vitamin is an antioxidant and destroyer of free radicals, the function of vitamin E remains obscure. 

Several studies indicate that inhalation exposure to chloroform may cause reproductive effects in animals. Rats exposed to chloroform during gestation had decreased conception rates after exposure to 300 ppm, but not after exposure to 100 ppm (Schwetz et al. 1974). Studies by Baeder and Hoftnann (1988) indicated that exposure to as little as 30 ppm chloroform resulted in increased fetal resorptions. Similarly, a decreased ability to maintain pregnancy, characterized by an increased number of fetal resorptions and decreased conception rates, was observed in mice exposed to 100 ppm chloroform (Murray et al. 1979). In addition to the reproductive effects described above, a signiftcant increase in the percentage of abnormal sperm was observed in mice exposed to 400 ppm chloroform for 5 days (Land et al. 1979). 

Adverse reproductive effects have been observed in animals fed PCB in the diet. Fetal resorptions were common, and dose-related incidences of terata were found in pups and piglets when females were fed Arochlor 1254 at Img/kg/day or more. Long-term low-level maternal exposure of rats before breeding and throughout gestation and lactation caused permanent hearing deficits, decreased serum thyroid hormones, and reproductive effects. PCBs have been observed in human cord blood and in tissues of newborn humans and animals. ... 

Increased fetal resorptions, but no teratogenic effects, were seen in rats exposed at 100 mg/%/day from day 3 of gestation. A weak genotoxic response was observed in mice treated in vivo as evidenced by an increase in sister chromatid exchanges in bone marrow and spermatogonial cells. ... 

In another experiment, exposure of rats to 600 ppm on days 7-15 of gestation caused 100% fetal resorptions, 390ppm caused skeletal and cardiovascular defects, and one cardiac malformation occurred at 130ppm. ... 

Indications of embryo or fetal toxicity include increased incidence of embryonic or fetal resorptions, reduced or increased weight or size of the fetuses, and delayed fetal development and dysmorphogenesis. Any of these findings in the absence of maternal toxicity constitute evidence of selective developmental toxicity. Abortion in rabbits is a frequent consequence of maternal toxicity, but may also occur as the result of a compound-induced embryo-fetal mortality. 

Reproduction Retinol and retinal are essential for normal repno duction, supporting spermatogenesis in the male and preventing fetal resorption in the female. Retinoic acid is inactive in maintain ing reproduction and in the visual cycle, but promotes growth and differentiation of epithelial cells thus, animals given vitamin A only as retinoic acid from birth are blind and sterile. 

Vitamin A, as retinal, has a clearly established role in vision (Chapter 23) and apparently has a specialized function in reproduction. In vitamin A deficiency no sperm cells are formed in males, and fetal resorption occurs in females. Rats deprived of vitamin Abut fed retinoic acid become blind and sterile but otherwise appear healthy.e bb Evidently either the alcohol or the aldehyde has an essential function in reproduction, whereas bone growth and maintenance of mucous secretions requires only retinoic acid. Indeed, retinoic acid is 100 to 1000 times more active than other forms of vitamin A in these differentiation functions.1 ... 

Bioassay methods include measurements of quantity required to prevent fetal resorption and for red blood cell hemolysis (in rat). Measurements also are made of liver storage in the chick. Physicochemical methods used include colorimetric two-dimensional paper chromatography,... 

Hepatonephritis and pulmonary edema were reported as causes of fetal death. The presence of PCE in breast milk was the cited reason for obstructive jaundice in a 6-week old infant (ref. 35. P 303). A study by Schwetz et al. (ref. 68) indicates that PCE may be teratogenic. Delayed skull-bone ossification and split stembrae were observed in mice, as well as increased fetal resorption, decreased fetal body weight and fetal subcutaneous edema. 

The wealth of information in animals administered DEHP for periods ranging from a few days to lifetime studies indicate that DEHP is a developmental and reproductive toxicant by mechanisms not yet completely understood. As discussed below, the mechanisms do not appear to involve binding of DEHP to the estrogen or androgen receptors. DEHP administered perinatally to females is embryotoxic and teratogenic (reduced fetal body weight, increased rates of abortion and fetal resorptions, skeletal... 

Mouse (albino) Gd 1-19 19 d (W) 46 F (increase in fetal resorption and post implantation loss) Trivedi et al. 1989 K2Cr207 (VI)... 

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