Birth anomalies not linked to common cause, investigation concludes
An investigation by the Colorado Department of Public Health and Environment of 22 reported anomalies in unborn children in Garfield County found no common underlying cause.
Dr. Larry Wolk, department executive director and chief medical officer, said, “Our investigation looked at each reported case and concluded they are not linked to any common risk factors.”
Department epidemiologists looked at more than a dozen factors including each mother’s place of conception and current address; drinking water source (municipal and well); proximity to active oil and gas wells; proximity to each other; the age, health, and family history of the mothers; the mother’s use of medications, supplements, tobacco, alcohol, caffeine and other substances; each mother’s prior pregnancies and deliveries; and ethnicity. While there were different risk factors identified for individual cases, no pattern emerged to suggest a common risk factor for the reported anomalies.
The cases, reported by Women’s Health and A Woman’s Place – two clinics located in Glenwood Springs, were from mothers with residences spread over a wide geographic area, not isolated in any single community. The department was asked to investigate due to the number of prenatal ultrasounds showing very rare congenital anomalies reported in late 2013.
The department’s birth defects registry mainly tracks birth defects after children are born. The study was unique in that it looked at unborn children with birth defects detected by ultrasound early in pregnancy. Therefore, a number of additional factors should be considered, including the limitations of the ultrasound as a diagnostic tool, observer variability, and the timing of the ultrasound. It is possible one of these variables may have accounted for an impression that there is a higher number of anomalies. In addition, because prenatal ultrasounds are not typically monitored by the state, there is no way to know if these cases represent a higher number than normal.
In addition, there was no single or common type of birth anomaly reported. Types of anomalies varied and included cardiac anomalies, commonly diagnosed autosomal trisomies, other suspected chromosomal anomalies and molar pregnancies.
Dr. Wolk said, “There is no state or federal registry of pre-birth anomalies that would show whether the cases referred to the department are greater or less than the number of cases occurring in the general population. While some may have expected the investigation would identify one or two risk factors that link these cases, no such link was found. It is natural to look at even a single birth anomaly and ask why. But sadly, birth anomalies do occur.”
The full report can be found under the Hot Topics section of the department’s webpage, click on Glenwood Springs Prenatal Report.