Oct. 11, 2002 - Children born to women who took antihistamines the year before becoming pregnant or during pregnancy were at increased risk of developing acute lymphoblastic leukemia (ALL), the most common kind of childhood cancer. The risk was also elevated if the child's father had taken the drugs.
In ALL, developing white blood cells, or lymphocytes, do not mature and become too numerous. This overproduction crowds the bone marrow, radically reducing the body's ability to form other normal and necessary blood cells.
Wanqing Wen, MD, of the School of Medicine at Vanderbilt University in Nashville, and colleagues evaluated more than 1,800 children with ALL, aged 14 or younger.
They found that amphetamines (diet pills) and mind-altering drugs, primarily marijuana, used by either parent before or during pregnancy also increased the risk of ALL for the child. Amphetamine use nearly tripled the risk, and mind-altering drugs nearly doubled the risk.
Their complete findings appear in the Oct. 15 issue of Cancer.
While few, if any, doctors ever recommend pregnant women take diet pills, much less smoke marijuana, it is not uncommon for women or their partners to have taken amphetamines or smoked marijuana the year before becoming pregnant.
In addition, it is not uncommon for doctors to prescribe allergy medication to pregnant women. Benadryl is one antihistamine-containing drug believed to be safe during pregnancy. Some doctors even prescribe it for short-term use to help pregnant women fight sleep problems.
The disturbing findings give new insight into the effects certain drugs can have on a child in utero or during early life. "Further studies are needed to establish the safety of these medications during pregnancy," write the researchers.
The researchers also found, however, that vitamin and iron supplements taken by the mother during pregnancy appeared to decrease the risk of childhood ALL. This is certainly good news, as women are advised to take prenatal vitamins before and during pregnancy. Some vitamins, such as folic acid, are known to reduce the risk of birth defects. This is the first study to suggest that vitamin and iron supplements may also reduce the risk of childhood ALL.
The investigators speculate that vitamin supplements may reduce the risk of having a child who develops ALL because they contain antioxidants, substances known to ward off disease and help boost the immune system. -->