The authors of a research paper describing associations between atrazine exposure and fetal gastroschisis (Waller SA, Paul K, Peterson SE, Hitti J. Agricultural-related chemical exposures, season of conception, and risk of gastroschisis in Washington State. Am J Obstet Gynecol 2010;202:241.e1-6) wish to correct 2 errors.

First, before 2003, cases of gastroschisis were identified only by the ICD-9 code 756.7, “congenital anomalies of the abdominal wall including gastroschisis, omphalocele and prune belly.” No chart review was performed to confirm the diagnosis. Therefore, the following 2 sentences in the online version of the Materials and Methods section should be removed. The article summary in the print edition did not include these sentences and is unaffected:

Taking this into account, once cases were identified, we increased the accuracy of the diagnosis by performing a brief review of the patients’ hospitalization charts and outpatient records. We made study inclusion decisions based on the combination of ICD-9 codes and clinical evidence, including the results of amniocentesis, fetal echocardiograms, and the descriptive findings at the time of delivery.

The authors report that this error resulted from “a misunderstanding about the construction of the Washington State Birth Record database. Although a chart review to confirm the diagnosis of fetal gastroschisis would be highly desirable, it is not practically achievable given the time frame and geographic dispersal for this study population. If any bias were to have been introduced by inadvertent inclusion of non-gastroschisis cases, this would likely have lead to a bias toward negative results. For this reason, we do not believe that the lack of chart review confirmation for fetal gastroschisis in any way alters the results or conclusions of this manuscript.”

Second, the manuscript contained a typographical error. The confidence interval for seasonal variation in the prevalence of gastroschisis (Results section, third paragraph, first sentence) should have read 1.0-1.5, not 1.1-1.5. This confidence interval is given correctly in Table 3, “Odds of gastroschisis by season of conception (n=3828),” which also appears in the print edition, labeled “Table.”