Pregnancy: Will smoking marijuana hurt the baby?

Doctors advise pregnant women not to use any drugs because they might harm the growing fetus. Although one animal study has linked marijuana smoking to loss of the fetus very early in pregnancy, two studies in humans found no association between marijuana smoking and early pregnancy loss. More research is necessary to fully understand the effects of marijuana smoking on pregnancy outcomes.

Some scientific studies have found that babies born to women who used marijuana during their pregnancy display altered responses to visual stimulation, increased tremors, and a high pitched cry, which may indicate problems with nervous system development. During pre- and early school years, marijuana-exposed children have been reported to have more behavioral problems and difficulties with sustained attention and memory than nonexposed children.

Researchers are not certain whether any effects of marijuana smoking during pregnancy persist as the child grows up; however, because some parts of the brain continue to develop into adolescence, it is also possible that certain kinds of problems will become more evident as the child matures.