Fetal movements are related to the muscle movements of the developing fetus in its mother’s womb. Baby kicking in the womb may be involuntary reflexes or movements in response to noise or touch. But you might ask, what if the baby is not moving during pregnancy?
Types of fetal movements
Not all fetal movements are alike. At first, the mother may feel a fluttering motion in her belly, which later becomes more powerful kick and will later feel like turning, twisting, or stretching. There are also movements related to baby hiccups in the womb.
Fetal movements can be divided into three categories:
Fetal movements become more complex over time
Before the 9th week of pregnancy, all the organs of the fetus move together as the baby’s nerves are still developing. The fetus arches its head and back.
In the ninth week of pregnancy, yawning and stretching can be seen on ultrasound. In the tenth week after fertilization, you may feel separate limb movement and leaps.
At the 11th week, the baby can open her/his mouth and suck her/his fingers.
At week 12 of pregnancy, the baby begins to swallow amniotic fluid, and at week 13 of pregnancy, the baby will move hands and feet more forcibly and kick and punch. The baby may also responds to the touches on the mother’s belly.
In weeks 14 to 20 of pregnancy, something wonderful occurs and the mother completely notices the baby’s movements. In the first pregnancies, the mother will usually not notice these movements until weeks 18-20 of pregnancy, but mothers who have been pregnant before will notice the fetal movements as early as week 14 due to their increased sensitivity and abdominal muscle relaxation.
From week 20 to week 36 of pregnancy, all types of fetal movements are felt: weak, strong movements and rotations. The baby moves all the joints and spine to ensure proper growth.
Over time, the pattern of the fetus’s movements changes and their soft movements decrease and, in turn, their movements become stronger and their rotations more frequent.
By week 28 of pregnancy, all babies respond to various stimuli. For example, if the baby is distressed by a loud noise, sudden movement or a feeling of falling, he or she may take a crouching position.
In the third trimester of pregnancy, the baby performs a movement similar to cycling with their feet, which is called stepping. This movement is important for the positioning of the baby and normal childbirth. At this time, the more the baby grows, the less space he or she will have to move, so the frequency and intensity of their movements will be somewhat limited.
What does baby not moving in the womb mean?
The rate of fetal movements during pregnancy is not constant. Between weeks 20 to 36 or 37 of pregnancy, early baby movements in the womb are mostly weak. But as pregnancy progresses, these weak movements decrease and stronger movements and fetal turning increase. From week 36 or 37 until the end of pregnancy, the baby’s powerful movements and rotations are reduced again, and they start moving slowly.
Fetal Movement Rhythm
The fetal movements have their own daily and nightly rhythms. The fetus is usually active between 9am to 2pm and 7pm and 4am. In the final month or after the pregnancy is over, the baby usually kicks during their light sleep!
Sometimes the fetus moves less during the sleep cycle, and the mother gets worried about the baby not moving in the womb. In general, each sleeping time of the fetus lasts from 20 to 40 minutes, but can it sometimes reach up to 90 minutes! The rest-activity cycle of the fetus is not in line with her mother’s sleep-wake cycle.
Feeling the baby kicks
Mothers often feel their baby’s movements better when they are lying down, sitting up and raising their legs, or when they are focusing on the baby’s movements. But when the mother is busy, she may not notice her child at all. So she may think that the baby is not moving as usual!
Factors affecting perception of fetal movements
Among the factors that impede the mother’s understanding of fetal movements and may be interpreted as the baby not moving the womb, the following can be mentioned:
Low volume of amniotic fluid that prevents fetal free movement
Obesity that results in the formation of a thick abdominal wall
Anterior placenta (which does not occur before week 28) that increases the thickness of the uterine wall at that point
Experiencing the first pregnancy with firm abdominal muscles
Substances such as alcohol, benzodiazepines, painkillers, and drugs such as methadone can cause both maternal and fetal inactivity.
Fetal inactivity and number of kicks
Whenever a mother suspects the fetus is inactive, further investigations are needed to ensure the fetus is healthy.
Some experts believe fetal health is linked to the number of kicks. This can be done in one of two ways:
1. The mother has to sit comfortably or lie slowly on her left side to increase the amount of blood circulating to the fetus, and then count 10 kicks and measure the time needed to reach the 10th kicks.
2. After a typical meal, the mother lies on her left side and counts the number of kicks in the womb within 10 to 15 minutes.
Usually more than 10 kicks within 2 hours is normal. A one-time decrease in fetal movements is negligible in 70% of mothers and requires no further investigation.
The baby not moving in the womb for one time is usually negligible
When is baby not moving in the womb dangerous?
When acute fetal distress occurs, usually the number of fetal movements increase, but most of these movements are slow and weak. Of course, in chronic fetal distress it has been observed that at least 12 hours before the fetal cardiac arrest, the fetus becomes extremely inactive or stops the movement altogether.
These conditions are called “motor alert signal” (MAS) and indicate the imminent death of the fetus. Changes in the heart rate of the fetus usually result in the death of the fetus within one to four days, if not before that time.
Factors associated with fetus inactivity
Among the factors that cause fetus inactivity are:
- Intrauterine growth restriction (IUGR), Fetal growth restriction (FGR) or Small for gestational age (SGA)
- Placental insufficiency
- Deficiency of amniotic fluid (Oligohydramnios)
- Imminent premature birth
- Fetal hemorrhage
- Intrauterine infections
- Complications of fetal inactivity
- The following are some of the side effects of decreased fetal movements:
- Congenital malformations (congenital anomalies)
- Birth of premature fetus
- Cerebral Palsy
- Intellectual disability
- Birth Weight Deficiency
- Fetal death
- Infant death in early neonatal period
- Increased risk of cesarean section
- Induction of labor
Evaluation of decreased fetal movements
When symptoms of inactivity appear, the mother’s history should be examined and subjected to physical examination and some other tests.
The path of the mother’s evaluation will vary depending on any risk factors or any unwelcome experiences in the previous pregnancy (s) of the mother.
But cardiotocography (CTG) and ultrasound are usually prescribed. In this test, fetal movemnets is assessed simultaneously with a heart rate-proportional test. Ultrasound helps to monitor fetal growth, fetal organs, and amniotic fluid volume.
If the cardiovascular test results are abnormal and the ultrasound is normal, your doctor will consider the possibility of fetal hemorrhage (FMH). Fetal hemorrhage accounts for about 4% of fetal deaths, usually the only sign of which is decreased fetal movement.