Increased use of prescription opioids during pregnancy is likely a contributing factor in the rise in rates of neonatal abstinence syndrome (NAS) in the United States, warns Nora D. Volkow, MD, director of the National Institute on Drug Abuse (NIDA).
“The steep increase in the number of opioid prescriptions dispensed in the United States has been associated with a parallel rise in their misuse, fatal overdoses, and heroin use,” Dr Volkow points out in an editorial published January in the BMJ. “More recently, attention has been focused on the large increase in the number of infants born with neonatal abstinence syndrome.”
In the United States, it is estimated that 14% to 22% of pregnant women receive an opioid prescription during their pregnancy, and there has been an increase in the prevalence of opioid use disorders in pregnant women, Dr Volkow notes. The United States has also seen an increase in the incidence of NAS, from 1.20 to 3.39 per 1000 live births between 2000 and 2009.
Dr Volkow notes that high prescribing rates of opioids to women during pregnancy have “probably contributed” to the recent increases in NAS.
She notes that the potential effects of in utero opioid exposure on the developing brain are unknown, but studies in rodents have linked it to birth defects in the central nervous system. Human epidemiologic studies have reported ties between opioid use during pregnancy and neural tube defects and other birth defects.
Studies have also suggested that opioid exposure may disrupt attachment between mother and baby, and cognitive impairment has been reported in children and young people born to women who misused opioids during pregnancy.
The lack of solid scientific data on the effects of opioids on fetal brain development, coupled with their known association with NAS, indicates that opioids “should be reserved for pregnant women with severe pain that cannot be controlled through more benign means, and ideally limited to a short term use,” Dr Volkow advises in her editorial.
“If long term use is unavoidable, such as for women in need of buprenorphine or methadone maintenance therapy for heroin addiction, then careful assessment and monitoring should be undertaken to minimize the risk of overdoses, NAS, and misuse,” she adds.