Fentanyl ingestion during pregnancy resulted in fetal abnormalities

American scientists described ten children with similar congenital malformations: reduced skull size, short length at birth, facial stigmas, wolf's mouth, equinovarus feet, hypospadias, short and wide thumbs, slightly conjoined second and third fingers, and a single palmar crease. Although all of these abnormalities resembled Smith-Lemley-Opitz syndrome, in which cholesterol metabolism is impaired, the medical team concluded that cholesterol metabolism may have been disrupted by the mother's ingestion of fentanyl during pregnancy. The study is published in Genetics in Medicine Open.

A similar set of congenital anomalies are often lumped together into a syndrome, the development of which is usually directly related to inherited disorders or exposure to teratogenic factors. For example, in Smith-Lemley-Opitz syndrome, there is a mutation in the DHCR7 gene responsible for the expression of the enzyme 7-dehydrocholesterol reductase. It is involved in the synthesis of cholesterol and when it is deficient, cholesterol precursors accumulate and cholesterol itself becomes scarce. This syndrome is often associated with reduced skull size (microcephaly), mental retardation, drooping of the upper eyelid, cataracts, fusion of fingers (syndactyly) and malformations of internal organs.

And fetal alcohol syndrome, in which the child is found to have a short and narrow eye slit, a wide flat nose bridge, a flattened lip groove and a thin upper lip, is directly related to the mother's alcohol use during pregnancy.

Karen Gripp and colleagues at Nemours Children's Hospital described ten children born with a similar set of congenital anomalies. These included microcephaly, short length at birth, facial malformations, wolf's mouth, equinovarus feet, hypospadias, short and wide thumbs, incomplete syndactyly of the second and third fingers, and a single palmar crease. In addition, in several patients, magnetic resonance imaging showed hypoplasia of the corpus callosum.

Since the anomalies found resembled Smith-Lemley-Opitz syndrome, the doctors performed a biochemical study and found that elevated levels of 7-dehydrocholesterol and 8-dehydrocholesterol were observed after delivery, but their values normalized after several months. Genetic analysis showed no mutations in the DHCR7 gene, hence the children did not suffer from Smith-Lemley-Opitz syndrome. However, the doctors noted that in all the cases described, the mothers of these children had taken fentanyl during pregnancy, a powerful opioid analgesic often used as a recreational drug.

Although it is too early to talk about the isolation of a new nosological unit, scientists suggest that the detected syndrome may develop due to abnormalities in cholesterol metabolism (as in Smith-Lemley-Opitz syndrome) caused by prenatal exposure to fentanyl. This potentially makes the drug a teratogen, but more research is needed into the pathophysiologic processes of the observed abnormalities.

However, scientists are looking for the causes of the development of common and familiar to physicians syndromes.