Too little evidence to show whether the unborn baby's growth improves when pregnant women take calcium channel blockers, and more research is needed.
Calcium channel blocker drugs relax muscles and lower blood pressure by reducing the intake of calcium into some cells. It has been thought that these drugs may improve the growth of an unborn baby who is growing more slowly than expected in the womb (impaired fetal growth). The review of trials has found too little evidence from trials on the effects of pregnant women taking calcium channel blockers. Only one trial, involving 100 women, has been included. However, there is some evidence of improved growth in some babies, and more research is needed into the effects of these drugs on both smoking and non-smoking women and their babies.