On the other hand, the individual prenatal amplification peaks of both CoV and AstV were higher in 2010, which may have enabled better perinatal protection and thus better survival of newborns.
However, our analyses of peak prenatal exposure, which focused only on dose, did not find any adverse impacts on birth weight or gestational duration.
However, it was women born in the 1980s who experienced the highest prenatal exposure and the highest peak concentration at any given age.
For substances such as methylmercury, the peak exposure occurs during prenatal development, when the fetus shares the contaminant from the mother's diet; human milk is not an important exposure pathway for this substance (Grandjean et al. 1995).
We estimated three measures of prenatal PCE exposure: cumulative exposure before pregnancy, peak annual exposure before pregnancy, and average monthly exposure around the time of conception.
We did not detect interactions with average or peak drinking water iAs concentrations and prenatal vitamin use.
As shown by Sakamoto et al. (2002) in their Figure 2, prenatal exposure of rats to MeHg showed a peak brain Hg concentration around PND1 that was four to five times greater than the level on PND10.
The peak of germ cell apoptosis occurs at prenatal, as well as neonatal when germ cells transit to the meiotic diplotene stage from the pachytene stage [17], [20].
The peak incidence during early childhood indicates that prenatal and perinatal factors may play an important role in its pathogenesis, but the evidence is rather limited and inconclusive (Hamrick et al, 2001; Schuz et al, 2001).
However, when temporal trends of childhood exposure reduction were compared with those for prenatal and postnatal exposure reductions, equivalent events (e.g., peak exposure declines) were delayed by the approximate duration of the childhood exposure period (9 years).
