Inês Afonso

5th-Year Student of the Integrated Masters
in Medicine

Dra. Ivone Lobo

Obstetrician Gynaecologist 
Sub specialist in Maternal
Fetal Medicine
Director of the Gynecology
& Obstetrics Unit

Fetal movement surveillance: 
An essential method of monitoring fetal health

HPA Magazine 23 // 2025

Assessment of foetal well-being is a fundamental practice in modern obstetrics, providing crucial indicators of the health and vitality of the foetus. Among the various monitoring techniques available, foetal movement surveillance (MF) stands out as a simple, accessible, and effective indirect method for early detection of problems. For more objective monitoring of foetal well-being, tests such as cardiotocography (nonstress test and contraction stress test), biophysical profile, and Doppler velocimetry of the umbilical artery are available.

Foetal movements represent a unique movement pattern for each foetus, being described as "butterfly" shaking, or kicking sensations, which can vary throughout pregnancy. Movements begin to be noticed between 16 and 24 weeks, reaching a peak at around 32 weeks and continuing until the end of pregnancy.
Foetal movement surveillance is a screening method that allows pregnant women to monitor foetal status without the need for intervention from a healthcare professional or specific equipment. The perception of these movements is reassuring for the mother, while decreased foetal movement (DFM) is often a cause for concern. This surveillance, therefore, assumes a role of great importance since DFM constitutes a warning sign, requiring a more objective assessment of foetal well-being. Early recognition of FMD allows clinical intervention at an opportune time, avoiding, whenever possible, progression to foetal or neonatal death.
The approach to foetal movement, focusing on physiological parameters, can be done in three stages: foetal biophysical activity begins, respiratory and tone movements appear, and, finally, these are perceived by the pregnant woman. Any factor that interferes in this chain can be responsible for DFM. The most serious causes include hypoxemia and foetal death.
However, other possible causes of DFM include:
• Decrease or increase in the volume of amniotic fluid;
• Foetal position (anterior position of the foetal spine);
• Anterior placenta;
• Foetal sleep states (sleep cycles can last up to 40 minutes, and the baby's circadian rhythm increases throughout pregnancy, increasing sleep time);
• Exposure to substances that cross the placenta (sedatives, alcohol);
• Maternal anxiety or stress;
• Prolonged fasting;
• Maternal smoking;
• First pregnancy;
• Early gestational age;
• Maternal position (sitting/standing versus lying down);
• Maternal physical activity;
• Mother's distraction;
• Obesity (although there are contradictory studies on this point).

Although the concept of DFM is not completely consensual, it is considered that it is the qualitative (subjective) perception of a reduction in movements in relation to the previously established pattern throughout pregnancy. Although difficult to objectify, the "count to 10" method suggests different alarm limits, such as:
• At least 10 foetal movements within 2 hours, with the pregnant woman at rest and concentrating on counting;
• At least 10 foetal movements during 12 hours of normal maternal activity;
• At least 4 foetal movements in 1 hour, with the pregnant woman at rest and concentrated;
• At least 10 foetal movements in 25 minutes (between 22 and 36 weeks) or in 35 minutes (from 37 weeks).

Currently, there are cell phone applications such as "Count the Kicks" that facilitate this monitoring.
Studies indicate that, at some point during pregnancy, around 40% of pregnant women express concern about DFM; however, most episodes are transient. Surveillance of foetal movements is especially important considering that foetal mortality among pregnant women with DFM is significantly higher (8.2 per 1,000 births) compared to the general obstetric population (2.9 per 1,000 births). Furthermore, up to 23% of FMD cases in the third trimester are associated with adverse outcomes such as foetal growth restriction, preterm birth, neonatal depression, and the need for emergency delivery.
Upon detection of DFM, an initial assessment must be carried out to exclude foetal death and determine the cause of decreased or absent movement.
Some key ideas must be reinforced: each baby has a unique movement pattern, and these must be noticed at least 10 times within 2 hours, with the pregnant woman at rest and paying attention to the count. In case of DFM, it is essential to seek medical attention immediately, without waiting for the next day. Another point to clarify is the myth that there is a decrease in foetal movements at the end of pregnancy. Finally, the total absence of movement until 24 weeks of gestation constitutes an alarm signal.

In conclusion, foetal movement surveillance is an indispensable tool in obstetric practice, allowing early detection of potential complications. Educating pregnant women about the importance of this regular monitoring is crucial to ensuring a healthy pregnancy and a positive outcome for mother and baby.
The HPA Group provides the Mamã Line (289 830 040), accessible 24 hours a day, to answer questions and provide guidance in each situation.

Referências/References:
Academia PNA. Material de estudo para a PNA 2023. “Cuidados pré-natais”. Disponível em: https://academiapna.com/
Academia PNA. Material de estudo para a PNA 2023. “Manual de ginecologia e obstetrícia”. Disponível em: https://academiapna.com/
HPA Saúde. “Movimentos fetais”. Disponível em: 
https://www.grupohpa.com/uploads/files/informacao_movimentos_fetais.pdf
Ministério da Saúde. “Descomplicar a gravidez - movimentos fetais”. Disponível em: https://www.chts.min-saude.pt/mais-saude/descomplicar-a-gravidez/movimentos-fetais/
UpToDate. “Decreased fetal movement: diagnosis, evaluation, and management”. Disponível em:
https://www.uptodate.com/contents/decreased-fetal-movement-diagnosis-evaluation-and-management