Infants who have been exposed to methadone in utero and are born to women with the CC genotype may be less likely to require treatment with at least two medications for neonatal abstinence syndrome as compared to infants born to women with the AA or AC genotypes. Be aware that this annotation is on the mother's genotype, even though the phenotype is observed in the infant and that this was not a statistically significant association. Other genetic and clinical factors may also affect severity of neonatal abstinence syndrome.