Methadone and the pregnant user: a matter for careful clinical consideration

The practice of placing all pregnant heroin users on methadone as the treatment of choice needs to be questioned. While it may be suitable for those who stabilise their illicit heroin use at or shortly after conception, its suitability for those who show little movement away from regular heroin use and its associated lifestyle is more circumspect. Neonates of women who continue heroin use throughout pregnancy are likely to be below birthweight and/or premature. As a consequence, they are in a less than optimal condition to cope with the additional assault caused by prescribed methadone such as neonatal withdrawal. This may help explain why the relative risk of neonatal mortality in women who continue illicit heroin use during pregnancy and are prescribed methadone, is greater than for those who continue to use heroin but are not prescribed methadone. Clinicians must take the time of maternal presentation and the likelihood of continued maternal heroin use into consideration when determining who is suitable for methadone and whether a reduced level of methadone will suffice. A number of different clinical scenarios are identified and possible management strategies discussed. The need to develop innovative services appropriate for pregnant women who continue regular heroin use, and for well-designed studies that define best practice for the management of these women is evident.