For women fighting opiate addiction, methadone maintenance during pregnancy helps them stay off drugs but it may have adverse effects on the fetus, American investigators say.
"Methadone maintenance offers clear benefits to the pregnant, opiate-dependent woman but it is not without adverse consequences for the infant," said Dr Lauren M.
Jansson from Johns Hopkins University School of Medicine, Baltimore.
"This research has additionally found that methadone used during pregnancy has significant effects on fetal neuro-behaviour that are independent of maternal effects."
At peak methadone levels, fetuses had significantly slower heart rate and fewer heart rate accelerations than at trough levels - signs of impaired heartbeat regulation.
The duration of fetal movements and the total amount of fetal activity were reduced by half at peak maternal methadone levels, the authors report in the American Journal of Obstetrics and Gynecology.
Mothers' responses were the same at high and low methadone levels.
"This raises an ethical question for the care of the pregnant, opiate-dependent woman," Dr Jansson said.
- REUTERS
