title: Mid-Gestational Enlargement of Fetal Thalami in Women Exposed to Methadone during Pregnancy.
abstract: Methadone maintenance therapy is the standard of care in many countries for opioid-dependent women who become pregnant. Despite recent evidence showing significant neurodevelopmental changes in children and adults exposed to both licit and illicit substances in utero, data on the effects of opioids in particular remains scarce. The purpose of this study was to examine the effects of opiate use, in particular methadone, on various fetal cortical and biometric growth parameters in utero using ultrasound measurements done at 18-22 weeks gestation. Head circumference (HC), bi-parietal diameter, lateral ventricle diameter, transcerebellar diameter, thalamic diameter, cisterna magna diameter, and femur length were compared between fetuses born to methadone-maintained mothers and non-substance using controls. A significantly larger thalamic diameter (0.05 cm, p = 0.01) was observed in the opiate-exposed group. Thalamic diameter/HC ratio was also significantly raised (0.03 mm, p = 0.01). We hypothesize here that the increase in thalamic diameter in opiate-exposed fetuses could potentially be explained by regional differences in opioid and serotonin receptor densities, an alteration in monoamine neurotransmitter systems, and an enhancement of the normal growth increase that occurs in the thalamus during mid-gestation.
authors.affiliation: Discipline of Paediatrics, Sydney Medical School - Nepean, The University of Sydney , Penrith, NSW , Australia.
authors.forename: Meredith
authors.initials: M
authors.lastname: Schulson
authors.affiliation: Discipline of Paediatrics, Sydney Medical School - Nepean, The University of Sydney , Penrith, NSW , Australia ; Charles Perkins Centre - Nepean, The University of Sydney , Penrith, NSW , Australia.
authors.forename: Anthony
authors.initials: A
authors.lastname: Liu
authors.affiliation: Perinatal Research Centre, UQ Centre for Clinical Research, The University of Queensland , Herston, QLD , Australia.
authors.forename: Tracey
authors.initials: T
authors.lastname: Björkman
authors.affiliation: Charles Perkins Centre - Nepean, The University of Sydney , Penrith, NSW , Australia ; Discipline of Obstetrics and Gynaecology, Sydney Medical School - Nepean, The University of Sydney , Penrith, NSW , Australia.
authors.forename: Ann
authors.initials: A
authors.lastname: Quinton
authors.affiliation: NHMRC Clinical Trials Centre, The University of Sydney , Camperdown, NSW , Australia.
authors.forename: Kristy P
authors.initials: KP
authors.lastname: Mann
authors.affiliation: Discipline of Obstetrics and Gynaecology, Sydney Medical School - Nepean, The University of Sydney , Penrith, NSW , Australia.
authors.forename: Ron
authors.initials: R
authors.lastname: Benzie
authors.affiliation: Charles Perkins Centre - Nepean, The University of Sydney , Penrith, NSW , Australia ; Discipline of Obstetrics and Gynaecology, Sydney Medical School - Nepean, The University of Sydney , Penrith, NSW , Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Peek
authors.affiliation: Discipline of Paediatrics, Sydney Medical School - Nepean, The University of Sydney , Penrith, NSW , Australia ; Charles Perkins Centre - Nepean, The University of Sydney , Penrith, NSW , Australia.
authors.forename: Ralph
authors.initials: R
authors.lastname: Nanan
keywords: methadone; neurodevelopment; neuroimaging; opiates; pre-natal drug exposure