Feeling your baby move is one of the most exciting things to happen during your pregnancy, making it seem suddenly much more real and for women who have had previous pregnancy losses, this movement can be immensely reassuring. Movements are usually first noticed between the 18th and 20th weeks of pregnancy although some women feel them as early as 16 weeks, particularly if it is your second or more pregnancy, and some women start to feel them much later than 20 weeks. Fetal movements are considered to be any type of kick, flutter, swish, or roll, and they quickly acquire a regular pattern. From as early as 20 weeks gestation, fetal movements start to become diurnal – with peak periods of activity happening during the afternoon and evening. Fetal movements are reduced when the fetus is ‘sleeping’, with the sleep period usually ranging between 20 and 40 minutes and usually not longer than 90 minutes. Changes in the number and nature of fetal movement as the fetus matures reflect normal neurological development.
Up until the 32nd week of pregnancy, the number of movements increases, and from this point onwards, the frequency of movements will level off until the onset of labor. By the time you reach the end of your pregnancy, the average number of movements within an hour is 31, with a range of 16 to 45, and the longest period between movements ranges from 50 to 75 minutes.
Factors that may influence fetal movement
Sedating drugs that cross the placenta may temporarily influence fetal movement; these include alcohol, benzodiazepines, methadone and other opioids.
Several studies have shown an increase in fetal movement following an increase of glucose concentration in the mother’s blood, and less scientifically, many women also report increased activity following a meal or snack. Some studies have reported a reduction in fetal movement due to cigarette smoking.
Are there factors which can influence a woman’s perception of fetal activity?
There is some evidence that women perceive the majority of fetal movements when lying down, fewer when sitting, and the least while standing. Consequently it is not surprising that pregnant women who are busy and not concentrating on fetal activity so often tend to report fewer movements. In addition, before 28 weeks of gestation, a placenta which is in the anterior position – at the front of your uterus – may decrease a woman’s perception of fetal movements. Perception of fetal position might also be influenced by how the fetus is positioned in the womb. A study found that in women who were unable to perceive fetal movements, even though they could actually see them on an ultrasound, 80 percent of fetuses were positioned so they were facing into the womb (anterior position).
Counting fetal movements
In general women are advised to be aware of their baby’s individual pattern of movements and fetal movements are most often measured by the mother. However there can be a large discrepancy between the actual number of movements and what the mother feels, with between 37% and 88% of the movements seen on ultrasound being detected, according to one study.
Here are some tips to monitoring your baby’s movements:
- Monitor movements at around the same time each day.
- Pick a time your baby is typically active, often after you’ve had a meal or snack.
- Lie down or sit in a comfortable position
- Count each movement you feel – these can be flutters, kicks, punches, jabs, or rolls – but do not include hiccups
- Record how long it took to feel ten movements.
You’ll more than likely start to develop an idea of how long it normally takes to reach ten movements. But remember, every baby is different, so some parents may only need 15 minutes to count kicks, while others take an hour or more. So don’t worry if you baby seems a little bit more or less active than normal.
Reduced fetal movement
After 28 weeks of pregnancy, if you are concerned about a reduction in or a lack of fetal movements you should immediately contact your healthcare provider. If you are unsure about whether or not movements are reduced, you should lie on your left side and focus on fetal movements for 2 hours. If you do not feel at least 10 separate movements in this time, you should contact your healthcare provider.
Once at your healthcare provider’s office, the main priority is to check for the presence of a heartbeat – this will usually be with a handheld Doppler. Once it is confirmed that your baby is still alive, you will more than likely under go cardiotocography (CTG) monitoring. This gives more information on the health of the baby and will usually initially be performed for around 20 minutes. A normal heart rate pattern which shows accelerations of the heart rate at the same that the baby moves is a good indication that that your baby is healthy. You may also undergo an ultrasound scan if there is a still concern for the baby despite a good CTG or if you have risk factors for stillbirth or fetal growth restriction.
Luckily most women, around 70 percent, who have experienced reduced fetal movement will go on to have an uncomplicated pregnancy.