Prenatal alcohol exposure can affect a child's growth up until age nine, a new study finds.

Researchers found significant prenatal alcohol exposure can affect a child's weight, height and head circumference, which are indicators of brain growth.

The findings suggest alcohol exposure in the womb could affect children's mental development, the researchers note in the journal Alcoholism: Clinical & Experimental Research.

"Our findings show that heavy drinking during pregnancy leads to marked growth restrictions at birth and that these effects persist through childhood," study author Dr. R. Colin Carter of Children's Hospital Boston said in a news release. "These effects may be detrimental to the children as growth deficits have been shown to be related to other health problems, such as lower IQ." He added the study found the effects of alcohol on growth were much more severe if the child had iron deficiency anemia as an infant, a condition that is common in the United States and worldwide.

The researchers studied pregnant women in Cape Town, South Africa, who were divided into two groups based on their drinking habits. One group included 85 women who had two or more drinks per day, or at least four drinks at one time. The second group included 63 women who either did not drink at all, or who had less than a drink per day.

Their babies were measured and weighed at ages 6.5 months, 12 months, 5 years and 9 years. The researchers found children whose mothers drank heavily while pregnant had reduced height, weight and head circumference, compared with children whose mothers were not drinkers, HealthDay reports.

To learn more about Alcohol and Pregnancy - Fetal Alcohol Effects (FAE), click here.