Sucralose is a sugar substitute that contains no calories. Although generally considered safe when used as a sweetener for sodas, there have been some concerns about the side effects of this additive when used by pregnant or nursing mothers. The research conducted thus far has been contradictory, so the best suggestion as of now is for pregnant women to avoid drinks sweetened with sucralose.

Of all the artificial sweeteners, sucralose is the most closely related to sucrose, which is common table sugar. From a chemical standpoint, sucrose has a molecule of glucose chemically bonded to a molecule of fructose. In contrast, sucralose has a molecule of galactose chemically bonded to the fructose molecule. This allows the sucralose molecule to trigger sweetness receptors on the tongue causing the soft drink to taste sweet. However, the compound cannot break down in the human body, so the compound is considered non caloric.

As it would be unethical to do research on pregnant women in order to determine the effect of the compound on the developing baby, any research must be done on animals. While a 2000 study suggested not effect on the fetal development of rabbits or rats, a 2010 study suggests the substance can reduce birth weight and length of the umbilical cord. The effect on human development is unknown.

For the safety of one's unborn child, sucralose should be avoided when pregnant. Unfortunately, other artificial sweeteners may be just as unsafe. None has been proven safe for use in pregnancy. This means pregnant women should stick with sugar sweetened foods and drinks until the baby is no longer breastfeeding. While sugar contains calories, the risk it brings to such moms is not as severe as that of sucralose or other artificial sweeteners. In addition, some research shows that diet drinks may have an adverse effect on individuals attempting to lose weight.