ESPE Abstracts

Background: Although thiamazole (MMI) is the first-line treatment for non-pregnant women with Graves’ disease, the teratogenic effects of this drug have been confirmed. Surgical anomalies known as ‘major MMI-related anomalies’ include omphalomesenteric duct remnants. This is a common difficulty when attempting to clarify whether there is any association between infrequent surgical anomalies and MMI exposure using data derived from women with Graves’ disease. So, it is necessary to investigate whether the incidence of infrequent surgical anomalies is associated with MMI exposure. Since our hospital is a specialized children’s facility, we are able to accumulate a large database of surgical diseases. Consequently, we could review the incidence of infrequent MMI-related surgical anomalies.

Objective and hypotheses: The objective of this study was to elucidate the association between MMI exposure during pregnancy and major MMI-related surgical anomalies.

Method: We reviewed 76 cases that attended our hospital over a 20-year period from 1991 to 2010. These cases received surgical treatment for omphalomesenteric duct remnants, omphalocele, or esophageal atresia. Based on the medical records of these patients, we investigated whether the incidence of these three anomalies was associated with exposure to MMI during pregnancy.

Results: Having excluded patients with chromosomal aberrations, we were left with a total of 68 cases. Of these, 12 had omphalomesenteric duct remnants, 14 had omphalocele, and 46 had esophageal atresia. The following result show the ratio of each anomaly for which MMI exposure caused. For omphalomesenteric duct remnants, five out of 12 were exposed to MMI; for omphalocele, two out of 14 were exposed, and for esophageal atresia, only one out of 46 was exposed. There was a significant difference in the ratio between omphalomesenteric duct remnants and esophageal atresia.

Conclusion: Based on medical records, we investigated whether there had been a history of MMI exposure during pregnancy among those patients presenting with major MMI-related surgical anomalies. From these data, we concluded that omphalomesenteric duct remnants were strongly associated with MMI exposure.