Possible Reasons for Decreased Fetal Movements The 34th week of pregnancy is an important time in the parenting journey, as your baby\’s development enters its final stages. However, many expectant mothers will find that at this time, the frequency of fetal movements may decrease, and the baby\’s activities will become less active than before. This is very worrying for many expectant mothers. Typically, there are different reasons for decreased fetal movement. It may be because the baby is sleeping or changing positions.