Prenatal multivitamin supplementation decreases low birth weight risk

An inadequate intake of micronutrients during pregnancy increases the possibility of nutritional deficiencies that can affect the normal growth of the baby. Low birth weight is often associated with increased infant mortality.

A new meta-analysis published online on June 9, 2009 in the Canadian Medical Association Journal showed that pregnant women that supplemented with multinutrient formulas experienced a reduced risk of giving birth to low birth weight babies compared with the risk experienced by women who did not receive the extra nutrients.

Researchers identified 13 trials that compared the effects of a multivitamin supplement with a placebo, or with iron and folic acid, which are currently recommended for pregnant women by the World Health Organization. Multivitamin supplements evaluated in the trials included a combination of vitamins A, B1, B6, and folic acid, and the minerals zinc, iron, and copper.

Compared to those receiving a placebo, women who supplemented with multivitamins had a 19 percent lower risk of delivering a low birth weight infant. The multivitamin group also had a 17 percent lower risk than those who received only the standard iron and folic acid supplements. The risk of preterm birth and the risk of delivering infants who were small for their gestational age were approximately the same among treatment and control groups.

Prenatal multivitamin supplementation was associated with a significantly reduced risk of low birth weight when compared with iron-folic acid supplementation alone.

CMAJ. 6/2009; 180(12).