Fetal movement is a crucial indicator of a baby's well-being during pregnancy. While some fluctuations are normal, a noticeable decrease in movements can sometimes signal potential complications, warranting prompt medical evaluation.

Fetal movement, often referred to as quickening, is among the earliest signs of fetal vitality. Consistent, stable movements throughout pregnancy generally reflect a healthy developing fetus.

Weak fetal movement can be a warning sign of fetal distress. If the placenta's supply of oxygen or nutrients diminishes (placental insufficiency), the baby's body prioritizes blood flow to vital organs like the brain and heart, reducing non-essential activities, including movements. Reduced fetal movement can lead to complications such as intrauterine growth restriction, stillbirth, or preterm birth.

Several factors can contribute to changes in fetal movement. Certain fetal abnormalities, such as neuromuscular diseases, central nervous system abnormalities, or genetic syndromes, can alter the normal movement function of the fetus. Additionally, maternal conditions like underlying medical issues, smoking, alcohol consumption, prolonged stress, or infections are risk factors for this situation.

Pregnant mothers typically begin to feel fetal movements clearly from week 18. For women who have had previous pregnancies, quickening often appears earlier, around week 16. However, for obese pregnant women, this sign might be delayed until 24 weeks of pregnancy. In a normal pregnancy, various movements, including body, limb, and respiratory movements, are fully established by week 20. The intensity of fetal movements also increases, reaching its peak after week 28 of pregnancy.

From week 34, the fetus may not move as vigorously because the space in the uterus becomes more restricted as the baby grows. Movements primarily consist of wriggling, kicking, or stretching. At this stage, the fetal nervous system is also nearing full development, forming distinct sleep-wake cycles. There may be times when mothers perceive less fetal movement. This normal variation needs to be distinguished from pathological reduced fetal movement. The benign biological rhythm of the fetus involves alternating sleep periods with active phases throughout the day. Babies usually sleep for less than 90 minutes, and movements often appear when the mother rubs her abdomen, drinks water, or listens to music.

Fetal heart monitoring is a method to assess fetal health when fetal movement is reduced. Photo illustration: Tam Anh General Clinic District 7

Pathological reduced movement may occur if a pregnant mother does not feel fetal movements after 24 weeks. Abnormal signs include: the fetus not reacting or making fewer than 10 movements within two hours, weak kicks or no kicks when there is external stimulation, and movements gradually decreasing in both number and intensity for more than 12 hours. If the pregnant mother experiences bleeding, abdominal pain, or high blood pressure, these could be accompanying signs of weak fetal movement.

If you do not feel fetal movements or feel weak fetal movements, you should go to the hospital immediately for examination. A doctor can then determine the cause and provide appropriate treatment. During the examination, the pregnant mother will undergo a color ultrasound to assess the condition of blood vessels, the placenta, and fetal health using a CTG machine, which records fetal heart rate and uterine contractions.

Dr. Nguyen Phuong Thao, Master of Medicine

Fetal Medicine Unit

Tam Anh General Clinic District 7