Methadone assisted rehabilitation of opioid addicts started in Oslo in 1996. The purpose is to compensate for the neuroadaption by keeping a steady and high consumption of methadone that neutralize the urge for opioids without giving the euphoric pleasures or the abstinence symptoms. 19 children have been born in Oslo while their mothers have taken part of the methadone program. They have been exposed to methadone in utero and as a result of neuroadaption, suffer the risk of neonatal abstinence syndrome (NAS). The symptoms are sleeping problems, high-pitched cries, sweating, sneezing, diarrhea, eating problems, tremor, convulsions, etc. In my group of children, 84 % showed signs of NAS. The pharmacological treatment of severe symptoms is Morphine mixture, with the dose being individually adapted to the abstinence score. The non-pharmacological treatments are shielding the children from unnecessary sensory stimuli like sounds and lights, and securing the mother-infant attachment. Methadone exposure in utero gives no risk of teratogenicity, but the children are born small for gestational age. All the children in my group except one where born at term, with an average weight of 2700 g (2,5-percentile) and with normal Apgare scores. All research show that pregnant women in a regulated methadone program have fewer complications in their pregnancy and delivery than women on illegal drug abuse. Methadone protects the child from intrauterine abstinence with the risk of oxygen deprivation and preterm delivery. There is still lack of knowledge regarding the long term effects of methadone exposure to the children.