NBC News
The number of babies born with serious birth defects that affect their growth and development is on the rise as researchers now have strong evidence that illicit fentanyl is causing the problems.
Hospitals have identified at least 30 newborns with what is being called “fetal fentanyl syndrome,” NBC News has learned. The babies were born to mothers who said they used street drugs, particularly fentanyl, during pregnancy.
“I’ve identified 20 patients,” said Miguel Del Campo, a medical geneticist at Rady Children’s Hospital in San Diego who specializes in children exposed to drugs and alcohol in utero. “I’m afraid this is not rare, and I’m afraid children (with this condition) are going undetected.”
The syndrome was first identified in 10 infants last fall by geneticists at Nemours Children’s Health in Wilmington, Delaware. The babies had specific physical birth defects: cleft palate, unusually small head, drooping eyelids, webbed toes and joints that were not fully developed. Some had trouble feeding.
The published research on the babies caught Del Campo’s attention. She had already diagnosed fetal alcohol syndrome in some children with similar abnormalities, even though their mothers denied drinking during pregnancy.
“After reading the article and reflecting on it,” he said, “I have recognized the potential for fentanyl exposure.”
Nemours geneticist Karen Gripp and her team were the first to identify the 10 babies with fetal fentanyl syndrome last fall. “This is another huge piece of the puzzle” that explains the defects, she said.
The babies’ birth defects closely resemble a rare genetic disease called Smith-Lemli-Opitz, a disorder that affects the production of cholesterol in the fetus, which is essential for proper brain development. But none of the babies had the disease.
The mothers’ reported drug use was a clear indication of the cause of the defects, but there was no scientific evidence that fentanyl stopped cholesterol production in developing fetuses.
When Gripp and a team of researchers at the University of Nebraska Medical Center exposed human and mouse cells to fentanyl, they found that the drug directly disrupted their ability to produce cholesterol.
“Fentanyl was not known to interfere so significantly with cholesterol metabolism,” Gripp says. “This is very important because cholesterol must be synthesized as the embryo develops.”
The article explaining this relationship was published in June in Molecular Psychiatry.
The risks of consumption
Illicit use of fentanyl during pregnancy is a risk factor for premature birth and stillbirth. Babies born after significant exposure to fentanyl in utero may experience seizures, vomiting, diarrhea, and may be irritable, fatigued, and have trouble feeding.
Despite the increased use of fentanyl, including during pregnancy, there is no evidence of a simultaneous increase in birth defects. And most babies exposed to fentanyl in utero are not born with the defects characteristic of fetal fentanyl syndrome.
New research helps explain it.
While two copies of the gene that causes Smith-Lemli-Optiz cause the syndrome, cells with only one copy of that gene were more likely to be affected by fentanyl exposure.
That is, a single copy of the gene can make some babies more vulnerable.
“Not everyone is equally susceptible,” Karoly Mirnics, one of the study’s authors and director of the Munroe-Meyer Institute at the University of Nebraska Medical Center, said in a news release announcing the results. “The potential adverse effects of any drug or chemical compound may depend on your genes, lifestyle and environmental factors. A drug may cause no problems for me and be catastrophic for you.”
Gripp expects the number of documented cases of fetal fentanyl to increase with continued awareness and research.
“The group is growing,” he said. “We anticipate that there will be many more patients.”
Del Campo, who is also an associate professor at the University of California, San Diego, said it’s critical to properly diagnose babies with fetal fentanyl syndrome so doctors can monitor them long-term.
“We need to know how these kids are doing. I have some 2-year-olds that are very concerning,” she said. “They’re just not growing or developing.”
