Similarly, in adjusted analyses of 233 individual chemicals restricted to those for which more than four cases or controls were exposed, only two – oxyfluorfen (OR, 1.6) and petroleum distillates (OR, 2.5) – showed an association with this risk; in these cases, the confidence intervals did not include unity.
"We basically got a general lack of association in a discovery, hypothesis-generating study. We have a detailed exposure assessment. ... We conducted many comparisons, and we’ve got modest sample sizes," Dr. Shaw concluded. "And the kicker is that none of the associations we looked at seemed to stand up for young maternal age."
"This is a useful negative study, and it is noteworthy that, even without correcting for multiple comparisons, there were no impressive positive findings," commented session cochair Dr. James Mills, an investigator with the Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Md.
In additional study results, analyses of exposure to those chemicals classified as reproductive toxicants, ones listed in California’s Proposition 65 (which aims to eliminate carcinogenic and teratogenic agents from drinking water and consumer products), and known endocrine disruptors, either alone or in combinations, did not alter the findings, according to Dr. Shaw.
Furthermore, there was no significant association of the combination of pesticide exposure and air pollution exposure (any of either vs. none) and the risk of gastroschisis.
Dr. Shaw had no relevant conflicts of interest.