Most congenital anomalies (birth defects) go unexplained, according to a new study from genetic researchers at the University of Utah School of Medicine. In their exhaustive review of birth defect reports, the analysts have found that only around 20% of cases are assigned definite causes. The rest remain inexplicable.
Utah Researchers Investigate Congenital Anomaly Causes
To perform their study, the group of obstetricians and pediatric geneticists at the University of Utah’s School of Medicine analyzed medical records from every birth logged in the State between 2005 and 2009.
Out of 270,878 total deliveries, only around 2% of children were born with birth defects, although this estimate is limited to cases of serious congenital anomalies. The research team excluded children who had been born with mild isolated birth defects, like distal hypospadias (in which the opening of the urethra is located on the underside of a male infant’s penis but remains functional) and certain non-severe forms of ventricular septal defect.
Vast Majority Of Birth Defects Never Explained
After identifying 5,504 medical records that described infants born with birth defects, the team asked a seemingly-simple question: why did these children develop abnormalities? The scientists reported their results in the prestigious British Medical Journal on May 30, 2017, but answers, they found, were few and far between.
Only 20.2% of cases had been attributed to definite causes, which broke strongly in favor of genetic or chromosomal mutations:
- 94.4% – explained by chromosomal or genetic conditions
- 4.1% – teratogens – chemical substances and viruses that affect fetal development
An additional 1.4% of the explained birth defect cases were associated with the potential consequences of twin development, including conjoined twins and twin reversed arterial perfusion, in which twins are born with a shared cardiovascular system.
Striking “Gaps In Knowledge”
The real news, however, is that nearly 80% of the reported birth defects could not be explained by any causal factors. “These findings underscore the gaps in our knowledge regarding the causes of birth defects,” the researchers wrote in summary. Our current lack of understanding is made even more glaring by the fact that birth defects are now the leading cause of infant mortality in the United States.
Today, 1 in 5 children who die before reaching the age of 1 will be claimed by the consequences of a congenital abnormality. This remains true, despite only 1 in 33 babies being born with a birth defect. We simply don’t know enough about congenital anomalies to save these precious lives. As the recent study’s results indicate, what we do know is largely confined to the domain of genetic abnormalities. Where environmental factors and pharmaceutical exposures are concerned, the medical community is still groping in the dark.
Knowledge Of Drug & Environmental Risks Nearly Nonexistent
While teratogens were described as causal in over 4% of cases, the vast majority of these birth defects were attributed, not to environmental exposures or dangerous prescription drugs, but to poorly-controlled cases of maternal diabetes. These cases are included among teratogens because maternal diabetes can have a dramatic influence on the “environment” in which fetuses develop: their mother’s body.
As many experts have pointed out, the number of children born with birth defects due to prescription medications is likely far higher than our current statistics show. The team from Utah agrees, calling for “better ways to objectively measure fetal exposures,” especially during the crucial periods of organogenesis, the phase of development when internal organs are formed. More accurately tracking which women have taken which drugs, the analysts suggest, is essential if we want to understand their myriad effects on fetal growth.
Complex Interaction Between Genetics & Teratogens
Most experts in the field now believe that a majority of congenital abnormalities are the result of both environmental exposures and genetic predispositions, or, more accurately, an interplay between the two. Unraveling this complex web of causal factors is just hard, plain and simple, but it’s made even more difficult by the extraordinary lack of support that birth defect researchers receive.
Trump Administration Hopes To Cut Birth Defect Funds Further
Congress budgets around $66 to $70 billion every year for Medicare and basic medical research. Less than one-thousandth of one percent of that money goes to fund birth defect research. In 2015, only $1.32 million went to scientific projects trying to explain congenital anomalies. In comparison, the financial toll that birth defects take on America is enormous, an estimated $2.6 billion every year in direct healthcare costs.
Due to a lack of government funding, research initiatives in Texas and Utah have been forced to close their doors. With President Trump now in office, this trend will almost certainly continue, Gizmodo reports. The Trump Administration’s budget proposals call for a 17% decrease in funds for the Centers for Disease Control & Prevention, including a 26% cut from the National Center on Birth Defects and Developmental Disabilities.