Dead implants

Oral doses of 0.3 g/kg acetamide administered on days 6 through 18 of gestation produced no toxicity or terata in rabbits. No maternal toxicity was seen at 1 g/kg, although one rabbit aborted fetal numbers and body weights were lowered, with no terata. At 3 g/kg, maternal toxicity was encountered, fetal numbers and weights were reduced, the number of dead implants was elevated, and cleft palate was seen. No reproductive, embry-otoxic, or teratogenic effects were observed in... 

Uteri with implantations are opened using round-ended scissors, and the number of implantation sites counted. Sites are classified as live or dead implants dead implants are usually categorized further, and the UK IRDG (11) recommends the following ... 

The C-section ( litter ) values, i.e., gravid uterus weight, corpora lutea, total number of implants, and numbers of live and dead implants (including separate categories of dead implants) are presented as means, together with an indicator of variation, typically standard deviation. Additionally, pre- and postimplantation losses are calculated for each female ... 

Effects on the number of live implants, other than those secondary to effects on total number implants previously described, are shown by increases in the number of dead implants (also presented as postimplantation loss). 

Dominant lethal Rats 40 males Dead implants (embryos)... 

Alternatively, one may ignore preimplantation DL and confine one s attention to implants, whether dead or alive. DL mutations would then be expressed as the proportion of dead implants among the total implants or per pregnant female, and the dissection may be made at any time after 10 days. If one dissects after 1 days, however, one will miss all pregnancies with no live fetuses, which are terminated at 2 days. 

The second group of female mice is subjected to the dominant lethal mutation test. This test is necessary not only to analyze effects of chemicals on early litters but also because a small effect on fertility which might be detectable by an increase in dead implantation, for example, may not show up in the average size of first litters of females being tested for total reproductive performance. Females in the dominant lethal study are caged individually with untreated males on the day of treatment and are... 

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