What is Fetal Movement?

Fetal movement is the movement in the fetus due to its own muscle activity. These first movements are not reflexive, but arise from self-generated nerve impulses originating in the spinal cord. Movement increases as the nervous system matures.
Why is it important?

The fact that the baby is now able to have its own muscle activity makes it special for the mother. It also marks the beginning of the crucial phase of pregnancy. Although, the heart starts to beat on the 23rd day after conception, fetal movement matters a lot. The mother will soon be able to feel the movement which makes her pregnancy experience even lively.
How does it feel?

When the fetal movement starts, pregnant women feel some fluttering in their bellies. This fluttering will change to more reassuring movements. The mother will soon experience kicks, jabs and nudges. Usually the movements last only a few seconds and are not felt by the mother. But, as the baby grows, usually by the end of the second trimester, the kicks grow stronger and more frequent. Studies show that by the third trimester, the baby moves about 30 times each hour. You're more likely to feel the baby move when you're in a quiet position i.e. when either sitting or lying down.
When does fetal movement start?

Fetal movement starts sometime between week 18 and week 24, when the pregnant women feel fluttering, also called quickening, in their bellies. A woman who is pregnant for the first time may not recognize the early signs of fetal movement. So, don’t worry if you’re past 24 weeks and have not felt any fetal movement yet. You shouldn’t worry as long as your doctor can hear normal heart sounds.
Fetal Movement Timeline

Week 12: Your baby should start to move, but you probably won't be able to feel anything because the baby is still so small and the movements last for only a couple of seconds. Week 16 or 18: Some pregnant women will start to feel tiny butterfly-like flutters. This quickening is better identified by second or third time moms. Week 24: You might begin to feel slight twitches as your baby hiccups as his/her movement has become more established. Week 28: Your baby is moving often now. Some of the kicks and jabs may take your breath away. Week 36: Your uterus is getting crowded as the baby grows and movements should slow down a bit as there isn't much space for the baby to move.
If you don't Feel it

A pregnant woman who hasn't felt any baby movement shouldn't worry unless it's already the 25th week. Some babies just naturally move less often than others. A lack of movement also may means that your baby is asleep. The movement reduces after the 32nd week as your baby, who has grown bigger, has less room to move around in the uterus. If you have been feeling considerable movements and the movements have slowed significantly, it's time to call your doctor. In any case, if you are nervous or concerned, be sure to speak with your doctor about how to best track your baby’s fetal movement.