Incidence spontaneous abortion

Lead is known to cause reproductive and developmental toxicity. Decreased sperm counts and abnormal sperm development have been reported in male workers heavily exposed to lead. Increased incidences of spontaneous abortion have been reported in female lead workers as well as in the wives of male lead workers (13). Lead crosses the placenta and has been found to cause irreversible neurologic impairment to the fetus at maternal blood levels as... 

In these 500 cases, there were 26 culture failures, an Incidence of about 5% Nine women of this group underwent a second aminocentesls, and successful cultures were obtained The other 17, or 3 4% of the total, did not obtain any results, either because of spontaneous abortions prior to the time a second amniocentesis could be performed (In four) or because the family elected not to proceed There were no Instances of severe or significant fetal Injury, although small linear "scars" were noted on four fetuses Three fetuses had abnormalities which were not related to the procedure Itself, Including spina bifida, osteogenesis Imperfecta, and congenital heart disease ... 

Reproductive Effects. Operating room nurses exposed to trichloroethylene have been reported to have an increased incidence of miscarriages, but they were exposed to many other anesthetics as well (Corbett et al. 1974). Survey results of 1,926 women who had spontaneous abortions revealed a greater risk of abortion associated with trichloroethylene exposure (Windham et al. 1991). This study is limited by multiple chemical exposure. Humans exposed to trichloroethylene in the drinking water in certain areas of the country have not shown adverse reproductive effects (Byers et al. 1988 Freni and Bloomer 1988 Lagakos et al. 1986a). 

NS (general population Reproductive No association between blood lead levels and the incidence of spontaneous abortion in exposed women 2 Murphy et al. 1990... 

Reproductive Effects. There is sufficient qualitative evidence to support the conclusion that at high occupational exposure levels lead has significant adverse effects on human reproduction, including increased incidences of spontaneous abortion, miscarriages, and stillbirths. The mechanisms responsible for these effects are unknown at this time, but many factors may contribute to these results. These factors include indirect effects of lead on maternal nutrition or hormonal status before and during pregnancy to... 

Reproductive effects from lead exposure have been documented in animals and human beings of both sexes. High occupational exposure levels in pregnant women have been associated with increased incidences of spontaneous abortions, miscarriages, and stillbirths. Some studies also seem to indicate that prenatal exposure to lower levels of lead may increase the risk of preterm delivery and reduced birth weight. Lead penetrates the placental barrier and has caused congenital abnormalities in animals. There is no conclusive evidence, however, that low-level lead exposure leads to an increased incidence of... 

In several epidemiological studies, no increased risk for congenital abnormalities, stillbirths, or spontaneous abortions was observed with occupational exposure to mercury. Exposure of pregnant rats on gestational days 10-15 at 0.5mg/m resulted in an increased incidence of resorptions gross cranial defects occurred at this dose when it was administered throughout the entire gestational period. "... 

A number of studies have examined pregnancy outcomes following paternal exposure or paternal and maternal exposure to 2,3,7,8-TCDD. No significant alterations in the incidence of spontaneous abortions were found in several studies of Vietnam veterans. In a case-control study conducted by Aschengrau and Monson (1989), no association was observed between paternal military service in Vietnam and the risk of spontaneous abortion (odds ratio [OR] of 0.88, 95% confidence interval [Cl] of 0.42-1.86). A limitation of this study is that service in Vietnam is not an adequate exposure surrogate for 2,3,7,8-TCDD exposure ... 

Changes in the number or structure of chromosomes account for nearly half the spontaneous abortions and for many of the congenital defects in livebom children. One in 200 newborn persons has a detectable chromosomal abnormality.188 188 An increase in this incidence could be detected in a moderate sample if it were carefully chosen. A drawback is the very long time—40 yr or more--that could elapse between parental e qposure and the birth of affected offspring. 

In 1971/ Herbst et al. (93) reported the unusual occurrence of vaginal clear cell adenocarcinoma in eight young women. The precipitating factor appeared to be the fact that their mothers had been treated with diethylstilbestrol (DES) in order to prevent spontaneous abortion and premature delivery in what were deemed to be high-risk pregnancies. Estimates place the incidence of clear cell adenocarcinoma of the vagina at 1.5 per 1000 women who were exposed in utero to DES (94). 

Several epidemiological studies have been completed to evaluate the effect of long-term exposure to hydrogen sulfide in humans. In general, these studies did not have good information on the levels and duration of exposure. There is some evidence that exposure in the workplace was associated with increased incidence of spontaneous abortion. There are limited data and information that can be used to determine whether children are more susceptible that adults to the effects of hydrogen sulfide. Most data are anecdotal. 

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