Children born to mothers prescribed methadone during pregnancy may be at risk of wide-ranging vision problems. This is according to a new study published in the British Journal of Opthalmology. According to the authors, there may be at least 350,000 children in the UK who have parents struggling with drug abuse.
Methadone is a synthetic opioid, which gives a longer lasting "high" and is much less likely to be abused. Methadone is usually prescribed as a heroin substitute, and is associated with a more stable maternal lifestyle and less chance of retarded fetal growth or premature birth. Most babies born to women who have used methadone during pregnancy have serious withdrawal symptoms, known as neonatal abstinence syndrome or NAS. These symptoms are severe enough for treatment in up to 80 percent of cases.
The British study examined the eyesight of 20 children with vision problems, whose mothers had taken methadone during pregnancy. Most of these children had also been exposed to either benzodiazepines or heroin while in utero.
About 95 percent of the children had poor eyesight, in addition to which 7 out of 10 had nystagmus (involuntary eye movement). Half of the children had delayed visual development. One in three children in the study also had strabismus (a squint). About 30 percent had blurred vision of near- or far-sighted vision problems. One in four children had impaired brain function in relation to their vision.
One in four children also had significant developmental problems and cerebral palsy. The causes of the children’s visual problems are not clear, but the developing visual system is particularly sensitive to unexpected stressors before birth.
Substance abuse during pregnancy is increasing in Britain. One study from a clinic said that between 11 and 16 percent of pregnant mothers were using at least one drug during their pregnancy.
