Serial levels of serum organochlorines during pregnancy and postpartum

In utero exposure to dichlorodiphenyldichloroethene and polychlorinated bip henyls, within the range found in the general U.S. population, may produce detectable effects in offspring. To design studies of the effects of in ute ro organochlorine exposure, we obtained data on the relationship between ge stational and perinatal maternal levels in females on several occasions. We studied 67 pregnant women in the United States who agreed to have their bl ood drawn once during each trimester and once postpartum. We examined the P earson correlation coefficient between the natural logarithm of levels (mu g/g serum lipid). The correlation, r, among revels in the first and third t rimester was .86 and .77 for dichlorodiphenyldichloroethene and for polychl orinated biphenyls. Correlations among levels determined at other times (i. e., second trimester and postpartum) were similar. On the basis of these re sults, we suggest that in studies of the effects of in utero or perinatal e xposure to the aforementioned compounds, the time when specimens are collec ted is not critical.