Women who avoid meat during pregnancy dramatically raise the risk of their children becoming hooked on drugs and alcohol, according to new research.

A study from the National Institute on Alcohol Abuse and Alcoholism found that adolescents aged 15 whose mothers refrained from eating meat while they were pregnant were more prone to substance abuse.

Specifically, they were almost twice as likely to indulge in underage drinking and smoking, and nearly three times as likely to use cannabis.

While recent health trends reflect larger numbers of people converting to vegetarianism, researchers are warning of the adverse affects of the lifestyle that could harm children.

For the study researchers analyzed the habits of 5,109 women and their offspring. The children of those who ate meat daily during their pregnancies were compared to those whose mothers abstained from meat during that time.

The due dates of the women the researches observed were between April 1, 1991, and December 31, 1992.

The researchers evaluated 5,246 of their children and the median age of the adolescent participants was about 15.5 years old.

The alcohol, drug and tobacco use habits of all the children were evaluated, which led researchers to link vegetarianism during pregnancy to an increased risk of substance abuse.

Study lead author Dr Joseph Hibbeln said that, while women are often advised to reduce their meat consumption, this can cause nutritional deficiencies that may affect the development of a baby's brain.

Most vegetarians have a B12 deficiency while pregnant, as the vitamin is mainly available from meats and shellfish.

Vitamin B12 is essential for the body to metabolize folic acid, a nutrient vital for the development of a healthy fetus.

Because of this, the implementation of vegetarian foods that are B12-rich along with more widespread use of supplements could prove beneficial for pregnant vegetarians.

Dr Hibbeln said: 'Among Western populations infants of vitamin B12 deficient mothers have poor brain growth, developmental regression, irritability, thrive poorly and demonstrate residual deficits in cognitive and social development.'