Related Experiment Video
Updated: May 14, 2026
Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale
Published on: August 25, 2014
Neonatal visual evoked potentials in infants born to mothers prescribed methadone
Laura McGlone1, Ruth Hamilton, Daphne L McCulloch
1Princess Royal Maternity, Glasgow, United Kingdom. lauramcglone@doctors.org.uk
Insights
Maternal methadone use during pregnancy is linked to abnormal infant visual development. Neonatal flash visual evoked potentials (VEPs) were immature and smaller in infants exposed to methadone in utero, suggesting a need for early visual assessment.
Area of Science:
- Neuroscience
- Developmental Pediatrics
- Pharmacology
Background:
- Maternal drug misuse during pregnancy can negatively impact infant development.
- Previous studies suggested impaired visual development in neonates exposed to methadone, but results were confounded by other factors.
Purpose of the Study:
- To investigate the effects of maternal drug misuse, specifically prescribed methadone, on neonatal flash visual evoked potentials (VEPs).
- To clarify the association between in utero methadone exposure and visual development in newborns.
Main Methods:
- A prospective cohort study involving 100 infants exposed to methadone in utero and 50 matched controls.
- Flash VEPs were recorded within 3 days of birth and classified by morphology (mature, typical, immature).
- Drug exposure was confirmed through maternal history and toxicology screening.
Main Results:
- Infants exposed to methadone in utero showed significantly more immature VEP waveforms (P < .001).
- VEPs had smaller amplitudes in the methadone-exposed group (median 27 µV vs 39 µV, P < .001).
- These differences were independently associated with prescribed methadone, even after controlling for other exposures.
Conclusions:
- In utero exposure to prescribed methadone is associated with altered neonatal flash VEPs.
- Infants exposed to methadone in pregnancy may require early clinical visual assessment due to potential visual pathway alterations.
Objective:
Drug misuse in pregnancy is associated with impaired infant visual development. Pilot data showed abnormal flash visual evoked potentials (VEPs) in neonates exposed to methadone in utero, but results were confounded by intrauterine growth restriction, gestation, and ongoing drug misuse. This large cohort study aimed to clarify the effects on neonatal flash VEPs of maternal drug misuse in pregnancy, including prescription of substitute methadone and subsequent development of neonatal abstinence syndrome.
Methods:
This was a prospective cohort study. Flash VEPs were recorded within 3 days of birth from 100 healthy infants of drug-misusing mothers prescribed substitute methadone during pregnancy and 50 comparison infants matched for birth weight, gestation, and socioeconomic deprivation. VEP morphology was classified as mature, typical, or immature, and amplitudes and implicit times of the major waveform components measured. Drug exposure was determined by maternal history, maternal and infant urine, and meconium toxicology.
Results:
VEPs from maternal drug-exposed infants were more likely to be of immature waveform (P < .001) and were smaller in overall amplitude (median 27 µV vs 39 µV, P < .001) compared with non-drug-exposed infants. Most infants were exposed to illicit drugs in addition to prescribed methadone; differences in VEP parameters were independently associated with maternal prescribed methadone and persisted after correcting for birth weight, cigarette smoking, and excess in utero alcohol exposure.
Conclusions:
In utero exposure to prescribed substitute methadone is associated with altered flash VEPs in the newborn period and these infants may warrant early clinical visual assessment.
