A Colorado state health investigation into an unusual increase in fetal birth defects detected by ultrasounds at two Glenwood Springs prenatal clinics during early pregnancy late last year has found no common underlying cause.
“Our investigation looked at each reported case and concluded they are not linked to any common risk factors,” Dr. Larry Wolk, chief medical officer for the Colorado Department of Public Health and Environment, said Friday.
The investigation involved 22 separate cases of rare fetal defects, or anomalies, reported by the medical staff at Women’s Health and A Woman’s Place, according to an 11-page report that is posted on the CDPHE website, at www.colorado.gov/cs/Satellite/CDPHE-Main/CBON/1251583470000.
The information was passed along to state health officials, who began an investigation into possible links. The mothers involved were from a large geographic area stretching from Carbondale to Rifle in Garfield County, as well as from Meeker and Snowmass Village.
A dozen potential factors were studied, including proximity to active oil and gas wells, which had been the subject of much speculation as a possible cause in the weeks after the investigation became public in late March.
“Obviously there was a lot of interest in the community as it relates to oil and gas,” Wolk said in followup interview. “But this was never designed, despite what some folks were asking, as a study of oil and gas effects on newborns.
“We do investigate that to the best of our ability, though,” he said.
“And in this particular case, there isn’t anything we could find to tie the two together,” Wolk said, adding the report shouldn’t be taken as either “an exoneration or implication” of industry impacts.
According to the health department report, just 40 percent of the mothers involved responded to questions about where they lived at the time of conception.
Of those, the majority (70 percent) lived farther than 15 miles from an active gas well, while the remainder lived between five and eight miles from the nearest active well, according to the report.
The cases “were not isolated in any single community,” according to the report.
David Ludlam, director of the West Slope Colorado Oil and Gas Association, said the health department report should put people at ease who had concerns about a possible industry link.
“Our industry takes health very seriously,” Ludlam said. “These anomalies are painful for the families who incur them and our hearts go out to anyone who has to face such challenges no matter the cause.”
Industry critic Peggy Tibbetts of Silt, who writes about oil and gas impacts on her blog, From The Styx, said the state health study seemed rushed.
“They just started looking at this, what, five or six weeks ago? And they’ve already wrapped it up?,” Tibbetts said. “It just feels like it was hurried, and designed to maybe come to a pre-ordained conclusion.
“It’s just puzzling to me that they wouldn’t want to do a longer, more in-depth study,” she said, pointing to a recent University of Colorado Denver School of Public Health study that found a possible link between drilling chemicals and fetal problems.
“As someone who lives here, I would just like to see a longer study done,” Tibbetts said.
Other factors studied in relation to the recent cases were drinking water source, both municipal and well; proximity of the mothers to each other; their 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.
The mothers ranged in age from 20 to 37, with only 9 percent in the “higher risk” range of 35 and older. Thirty-two percent of the mothers are Hispanic.
Since the cases were reported, 36 percent of the pregnancies, or eight, resulted in miscarriage, voluntary abortion or were stillborn, Wolk said.
Two cases ended up being molar pregnancies, involving embryos that are malformed to the point that they can’t survive, he said.
Three of the babies have been delivered and are receiving medical care, he added, while six are progressing toward full term and three of the mothers have left the area and were not tracked.
“While there were different risk factors identified for individual cases, no pattern emerged to suggest a common risk factor for the reported anomalies,” Wolk said in a prepared statement.
The state health department mainly tracks birth defects after children are born, so this particular study of defects detected by ultrasound in unborn children was unique, he said.
For that reason, the report indicated that 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,” according to the report.
“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.”
There was also no single or common type of birth anomaly reported, the report clarified. Types of anomalies varied and included cardiac anomalies, commonly diagnosed autosomal trisomies, other suspected chromosomal anomalies and molar pregnancies, the report 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,” Wolk said.
“While some may have expected the investigation would identify one or two risk factors that link these cases, no such link was found,” he said. “It is natural to look at even a single birth anomaly and ask, why?,” he said. “But sadly, birth anomalies do occur.”
The full CDPHE report can be found under the “Hot Topics” section of the department webpage, then click on Glenwood Springs Prenatal Report.
“While there were different risk factors identified for individual cases, no pattern emerged to suggest a common risk factor for the reported anomalies.”
Dr. Larry Wolk
Chief medical officer for the Colorado Department of Public Health and Environment