Smoking
Research has revealed that pregnant women who smoke, give birth to children with a lower birth weight. It seems unlikely that this is the only effect on the foetus, yet to date no other abnormalities have been proven.
If a pregnant woman smokes cigarettes, she is advised to stop. If the woman is not capable of doing this, she should be advised to reduce the number of cigarettes smoked per day. The benefit of switching from cigarettes with a high nicotine and tar level to cigarettes with a low nicotine and tar level is questionable and is negligible if the pregnant woman then increases the number of cigarettes smoked per day.
Alcohol consumption
The teratogenic effect of excessive alcohol consumption has been proven. If pregnant women drink a glass of an alcoholic beverage on an incidental basis, it will probably not be harmful. The boundary between harmful and non-harmful alcohol consumption is unknown. Pregnant women are therefore advised to refrain from drinking alcohol altogether.
Drug Use
The effect of marijuana (cannabis, hashish) on the human embryo and foetus is uncertain. This uncertainty is, amongst other things, based on the fact that marijuana use is closely associated with alcohol, nicotine and hard drug use. Intra-uterine growth retardation, congenital abnormalities and neurological abnormalities appear to be more prevalent among marijuana users. The use of marijuana is advised against.
The use of hard drugs (opium derivatives, amphetamines, methadone) is very harmful during pregnancy. These substances pass through the placenta and can cause a wide range of abnormalities in the foetus. Moreover, the child can be born addicted. The need for a mother to ‘kick the habit’ is vitally important for her health and for her role as mother and carer of the child. Pregnant women who are addicted to hard drugs should receive multidisciplinary treatment. The best advice would appear to be to allow the pregnancy to be monitored by a gynaecologist. The newborn will require paediatric observation/treatment.