Maternal weight gain

HCDD. Administration of 0.1-100 / g HCDD/kg/day was associated with a dose-related decrease in maternal weight-gain during gestation. Gross necropsy examination at the time of cesarean section revealed evidence of maternal toxicity only among dams receiving 100 /xg/kg/day (pale, friable liver 3/20 dams serous atrophy of fat, 1/20 dams). 

Hexachloroethane resulted in tremors at 260 ppm, with no neurological effects at 48 ppm. Transient mucopurulent nasal exudate in 85% of the animals and an unspecified decrease in maternal weight gain were noted in animals at 48 ppm. This effect was considered a result of an endemic mycoplasma infection and was not observed at 48 ppm in the 6-week study (Weeks et al. 1979). The 260-ppm concentration is a serious LOAEL for neurological effects and the 48-ppm concentration is aNOAEL. 

Female mice and rats exposed 6 hours/day at concentrations of 10, 68, or 152 ppm during gestation had reduced maternal weight gain at the higher doses embryotoxic effects and increased resorptions occurred in the mice exposed at 68 and 152 ppm. ... 

Dose-dependent decreases in maternal weight gain and food consumption were observed... 

Sprague-Dawley rats and Swiss CD-I mice were exposed by inhalation to 0, 280, 1400 or 7000 ppm [800-19 530 mg/m ] isoprene for 6 h per day on seven days per week on gestational days 6-19 (rats) or 6-17 (mice) (lARC, 1994). There was no adverse effect on rat dams or other reproductive index at any dose level. The only fetal malformation observed in rats was reduced ossification of the vertebral centra, which occurred at 7000 ppm isoprene. In mice, there was reduced fetal body weight at all dose levels and decreased maternal weight gain in the 7000-ppm group. Also in the 7000-ppm group, there was an increased incidence of supernumerary ribs but no increase in fetal malformations. 

There were slight decreases in maternal weight gain during the treatment period and in the birth weights of the pups bom to rats given chloroacetonitrile orally at a dose of 55 mg/kg bw daily on gestation days 7-21 (lARC, 1991). 

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