More pregnant women using meth

Methamphetamine use by pregnant women is rising sharply and it is feared the drug may be harming their babies' brains.

The number of referrals to the alcohol drug and pregnancy team at National Women's Hospital involving methamphetamine users has risen more than five- fold - from six in 2001 to 34 last year.

These are the women who admit to using methamphetamine, also known as speed; the number who do not is thought to be far higher.

Auckland University health psychologist Dr Trecia Wouldes said yesterday that reports from midwives and other hospitals indicated the number of pregnant methamphetamine users had continued to rise this year, as more women took to the drug.

Methamphetamine, like alcohol, crosses the placenta. Foetal alcohol syndrome can cause many problems in children, including facial deformities and mental retardation.

In today's New Zealand Medical Journal, Dr Wouldes and colleagues say methamphetamine's effects on foetuses is unknown, but studies of that drug, amphetamine or crack cocaine in humans and animals suggest development after birth is likely to be affected adversely.

This is because of either the drug's direct effects in the uterus or the environment in which the child is raised, the authors say after surveying existing research.

They say chronic high use in adults has been linked to heart damage, violence and psychosis.

A study of rats exposed to the drug in the uterus found eye defects, growth retardation and delayed motor development.

Several small-scale studies of prenatal human exposure found problems including premature birth and retarded foetal growth.

A Swedish study found prenatal amphetamine exposure was linked with aggressive behaviour in childhood and lower academic and sporting achievement in adolescence.

Cocaine has some similarities to methamphetamine, the researchers say.

One study found "lower scores related to heavy cocaine exposure on tests of recognition memory at 6 and 12 months, and suggested that these infants had difficulty modulating their arousal and attention".

Dr Wouldes said because of weaknesses in the human studies more research was needed to establish the actual effects on children of foetal methamphetamine exposure.

She is about to start such research in Auckland - linking with a study already under way in the United States - by enrolling mothers after they have given birth.

"Quite often these things aren't noticeable at 6 months. They tend to be problems of attention and memory and arousal, so are not as obvious early on. Our intention is to monitor throughout early childhood."

Dr Carl Kuschel, the clinical director of National Women's neonatal intensive care unit, said he and his colleagues had no idea what the effects of prenatal exposure might be.

"I suppose the potential effect it may have because it's a stimulant is that at a time when the foetus' brain is wiring up and relying on a lot of chemical signals to make sure this bit of the brain gets connected to that bit - that could be disrupted."