In-utero fetal activity is seen as the hallmark of fetal wellbeing and a vital marker in the routine surveillance of unborn babies, with a further advantage that it can be assessed regularly by the mother with no need for specialist equipment or in patient care (Mangesi and Hofmeyr, 2007). However, there is currently no consensus on what constitutes reduced fetal movements leaving clinicians with limited guidance on definition and, therefore, diagnosis and management (Hofmeyr and Novikova, 2012)
In addition to being a precursor to fetal demise, a reduction in the normal pattern of fetal movements can also be associated with a number of clinical problems including intrauterine growth restriction (IUGR) and, less commonly, fetal abnormalities; in the case of structural conditions, with an anterior placenta (Frøen et al, 2001; O'Sullivan et al, 2009). There is concern that those fetuses at increased risk of stillbirth, who may undergo circulatory adaptations to compensate for reduced utero placental perfusion, may be missed during traditional antenatal surveillance (Alfirevic et al, 2010).
Although the UK stillbirth rate has reduced slightly over the years (5.5 per 1000 births in 2005, compared with 4.7 per 1000 births in 2013), it remains one of the highest in high-income countries (Office for National Statistics (ONS), 2014; World Health Organization (WHO), 2014).
Given that IUGR is regarded as the greatest risk for avoidable adverse fetal and neonatal outcomes, this article will discuss the importance of fetal wellbeing in relation to assessing in-utero activity.
Importance of assessing fetal movements
Over 30% of stillbirths occur after 37 weeks and the UK currently has one of the highest stillbirth rates in the developed world (Centre of Maternal and Child Enquiries, 2010). It has, however, experienced a small reduction in this rate, which is most likely due to advances in maternity care (Flenady et al, 2011a). However, in the last 10 years, the reduction in the UK's stillbirth rate has failed to keep pace with other high-income countries’ (Figure 1). In Norway the stillbirth rate has reduced by 50% in 20 years to a current rate of 2.2 per 1000 births, more than half the current stillbirth rate of the UK (WHO, 2014).
Studies have shown that a reduction, or absence, of perceived fetal movements, causing a deviation from their normal pattern of movements usually precedes fetal demise (Grant et al, 1989; Harrington et al, 1998). This reduction in fetal activity is as a result of physiological adaptations that the fetus undertakes in response to suboptimal uterine conditions. In response to these conditions, the fetus limits unnecessary energy expenditure and redistributes circulation to those organs essential for survival; brain, heart, lungs and adrenal glands. These adaptations also result in the fetus limiting fat accumulation and growth resulting in IUGR (Richardson and Bocking, 1998).
In over 55% of cases of fetal demise, placental insufficiency and IUGR were retrospectively found to be compounding factors (Figure 2). IUGR is defined as a condition where the fetus is unable to achieve its genetically determined potential size and differs from other small for gestation age fetuses (SGA) who may have normally distributed fat stores for their gestational age along with an absence of fetal circulatory adaptations (Williams et al, 1982). Those fetuses may not be pathologically growth restricted but small as a result of either a chromosomal abnormality or genetic makeup; known as constitutionally small (WHO, 1997).
A prospective cohort study in Norway in 2010 examined the stillbirth outcomes for over 46 000 women in 14 hospitals who presented following an initial period of reduced fetal movements. The intervention was the introduction of a leaflet for women explaining fetal activity and how to assess this along with a self-completed chart documenting fetal activity during the day. The study's self-assessment fetal movement chart enabled women to understand their baby's movements and allowed them to become aware of a pattern of fetal movements. The results saw a statistically significant reduction in the stillbirth rate of almost 50% versus the traditional method of assessing fetal movements attaining an arbitrary amount of activity within a set time period, standardised for the population rather than customised in those women who perceived reduced fetal movements (Tveit et al, 2010a). Following publication of this study, a correction was required after inaccuracies in the data were uncovered, this correction, however, did not change the estimate of reduced mortality rates (Tveit et al, 2010b).
Several other studies found that the use of routine counting of fetal movements was associated with an increase in hospital antenatal admission and caesarean sections on the basis of reduced fetal activity (Enkin et al, 2000). This evidence may lead to further confusion as to the optimal method of fetal surveillance.
In 2013, an observational study examining three regions of the UK, using data on stillbirth from the ONS, found that the introduction of customised growth charts reduced the stillbirth rate by 22% in high-uptake areas of the country (Gardosi et al, 2013).
Customised growth charts appear to offer a more robust method of detecting SGA fetuses than the traditional method of identifying a defined deficit between symphyseal fundal height (SFH) measurement and the gestation of pregnancy (Gardosi et al, 2013). Customised growth charts are generated using unique information from each woman and each SFH measurement is plotted at regular intervals with a drop in growth trajectory or static growth a trigger for an ultrasound scan measuring fetal growth, liquor volume and umbilical Doppler (Gardosi et al, 2013).
Implementation of customised growth charts required a period of staff training to ensure standardised use of the charts and method of measuring SFH. However, there remains disparity within maternity departments in the UK over the use of SFH measurement and customised growth charts for all women (Gardosi et al, 2013). The implementation of such a surveillance tool and resultant training may place a logistical and financial burden onto already stretched NHS Trusts thus reducing uptake and compliance.
Although customised growth charts can detect a number of SGA fetuses, they cannot detect all of those as risk of fetal demise, therefore a combination of customised growth charts and additional methods of fetal assessment may offer a greater level of surveillance (Royal College of Obstetricians and Gynaecologists (RCOG), 2011).
How to assess fetal movements
The RCOG states that fetal movements are normally felt from between 18–20 weeks; however, this can be earlier in multiparous women and later in primiparous women. These movements tend to become more pronounced and more frequent as the pregnancy progresses peaking and plateauing by around the 32nd week of pregnancy. From 32 weeks, the fetus will normally develop a pattern of movement and sleep that the mother should be accustomed to, with the afternoon and evening being the peak period of activity. The number of movements felt per hour range from 16–45 with an average of 31 (RCOG, 2011).
However, the information given to women on self-assessment by clinicians varies widely. Some women are advised regarding a set number of movements to look out for per hour while others are asked to note when their baby moves from 32 weeks of pregnancy and notify their midwife if that pattern of movement reduces. Given that the greatest periods of activity are during busy periods of the day some women may misperceive a reduction in fetal movements using the latter method of assessment (Heazell et al, 2008).
Furthermore, women who either work, or care for children tend to lack the time to spend assessing movements at a particular time of day, especially for a prolonged and sustained period of time. If women are not made aware of the importance of self-assessment of fetal movements, they may choose not to comply with this method (Gomez et al, 2003).
It is apparent that many women are confused about exactly how to assess their baby's movements and what constitutes a movement (Raynes-Greenow et al, 2013). Further concern surrounds the perception of fetal movements when women are distracted either by work, family or social commitments (Saastad et al, 2011). Many of those women claim to be anxious around their responsibility for assessing their baby's movements but fail to be given clear, simple guidance by their caregivers on how to undertake this.
Furthermore, a Cochrane review examining fetal movement assessment of either routine fetal movement counting, selective fetal movement counting, or none at all found that women's compliance with self-assessment of fetal movements was higher using the more objective method of counting a set number of kicks per time limit. However, a lack of agreement on the ‘gold standard’ of self-assessment of fetal activity by clinicians and researchers may add to the anxiety and confusion felt by women. The study found that women felt more comfortable with an objective target for fetal movements rather than the more abstract assessment of their pattern of movements (Mangesi and Hofmeyr, 2007).
There is a need to educate women on the importance of fetal movements and their association with fetal wellbeing. Current National Institute for Health and Clinical Excellence (NICE) guidance does not advise routine fetal heart auscultation during antenatal appointment as this may falsely reassure women who have noticed a reduction in their baby's movement pattern and may delay prompt access to a formal assessment of fetal wellbeing (NICE, 2008).
Education on the importance of fetal movements in relation to fetal wellbeing can be reinforced from the first appointment with the midwife and continued throughout pregnancy to ensure that the message is clear. From 20 weeks gestation women can be shown how to palpate their baby's movements and advised that lying on their left side in a comfortable and relaxed position will illicit more palpable movements (RCOG, 2011). This is especially useful in those women identified as having an anterior placenta, a frequent cause of maternal perception of reduced fetal movements (Hofmeyr and Novikova, 2012).
Women should also be informed that the type of movements may change as their pregnancy progresses but that the frequency of those movements should not reduce. However, there is a paucity of evidence and thus, a lack of agreement over what constitutes reduced fetal movements. This makes a consensus of advice difficult and may have resulted in the wide variation throughout the country of best practice for clinicians regarding the assessment of fetal activity (RCOG, 2011; Gardosi et al, 2013).
The information that appears to be consistently given to women regarding reduced fetal movements is if they feel that their baby has moved less than previous days to seek advice from their midwife.
These issues present a greater problem for those women at a higher risk of stillbirth or where the fetus is known to be growth restricted. If women are made aware of the importance of fetal movements earlier in pregnancy, they may pay more attention to their baby's movement patterns and become more aware of any reduction (Alfirevic et al, 2010). In order to provide women with a more objective method of assessment it may be prudent to look at other countries' methods of fetal movement self-assessment, such as Norway.
Care pathway in the event of reduced fetal movements
The RCOG guidelines advise that women who have reported with a history of reduced fetal movements are assessed firstly with a cardiotocograph (CTG). If the CTG is normal and their perception of reduced fetal movements has resolved, they should then be advised, that with a subsequent episode of reduced fetal movements of less than 10 movements within 2 hours, to contact their maternity unit (RCOG, 2011). However, as discussed earlier, there is no agreed definition of reduced fetal movements and for those extremely active fetuses an arbitrary perception of 10 movements per 2 hours may not indicate fetal wellbeing and in fact may lead to women failing to seek prompt medical assessment. Until further research is conducted to assess what constitutes reduced fetal movement, this standard should continue to be used.
Those women on initial assessment, who continue to report a reduction in fetal movements, should then be offered an ultrasound scan for amniotic fluid volume and fetal growth. The use of biophysical profile on ultrasound scan to assess fetal wellbeing is no longer advised and fetal umbilical Doppler assessment is not considered.
Where the results of the CTG and ultrasound scan are abnormal, or suggestive of IUGR, management should then be as per each units' protocol; either further growth scans, induction of labour or caesarean section. The risks of induction of labour with an already compromised fetus are high and as such there is an increased risk of delivery by emergency caesarean section (Boers et al, 2010). The risks and benefits of each mode of delivery should be discussed with the woman in order that she can make her own informed decision.
Recommendations for practice
Although the responsibility for fetal wellbeing can be shared, only women truly have the capacity to assess and establish the normal pattern of fetal movements. However, women are then required to be the sole arbiter of whether or not their baby has reduced fetal movements without the benefit of robust criteria (Hofmeyr and Novikova, 2012).
Women should be informed as early in their pregnancy as possible of the importance of fetal movements as an indication of fetal wellbeing to ensure that this message is reinforced as often as possible. This may reduce women's misplaced reliance on fetal heart auscultation as a method of assessing fetal wellbeing. Additionally, it may ensure that women pay more attention to fetal activity earlier in pregnancy and recognise the importance of taking time out of their day to assess this (NICE, 2008).
Women at greater risk of stillbirth or those undergoing serial growth scans should be informed of the significance of reduced fetal movements and that any perception of a reduction in fetal movements should necessitate urgent assessment in their maternity unit (Flenady et al, 2011b).
Current NICE guidance advises that midwives do not routinely auscultate the fetal heart during routine antenatal appointments to avoid the misconception that the presence of a fetal heart rate indicates fetal wellbeing. Not only should this discourage the use of hand held fetal Doppler machines by women, it may also reinforce the importance of assessing fetal movements and to seek prompt treatment for a reduction in those movements. Furthermore, women should be informed antenatally that auscultation of the fetal heart offers no clinical significance in relation to fetal wellbeing (NICE, 2008).
Once women have sought advice for their perception of reduced fetal movements it is important that they are not treated as ‘anxious mothers’ by midwives and obstetricians. Many women will report more than one episode of reduced fetal movements during their pregnancy and disempowering women over their perception of their baby's movements may discourage them from seeking subsequent prompt assessment (Heazell et al, 2008).
Additionally, those women who present with an anterior placenta may well report reduced fetal movements without palpating their abdomen. For those women it is important that midwives and obstetricians educate them on the technique for palpating for fetal movements than risk women feeling incapable of assessing fetal movements independently (Figure 3).
The language that we use as clinicians when caring for women both empower and disempower them. Midwives should be mindful that fetal movement patterns can only be detected by women and as such their perception of a reduction in that pattern should be accepted. Implying that women have simply failed to detect movements prior to a formal hospital assessment may devalue their skills at assessing their unborn baby's wellbeing and place a greater emphasis on the skills of the clinician, as a consequence adding confusion over who holds responsibility for the assessment of fetal movements (Saastad et al, 2011).
Conclusion
The presence of fetal movements is a significant indicator of fetal wellbeing in women who are at low risk of stillbirth; the reduction, or absence, of fetal movements is a recurring factor in stillbirths (Hofmeyr and Novikova, 2012). It is important that women are aware of the technique and significance of self-assessment of fetal movements; however, a lack of consensus on what constitutes reduced fetal movements has led to a wide variation in practice throughout the UK (Mangesi and Hofmeyr, 2007).
While the introduction of customised growth charts in some areas of the country has reduced the stillbirth rate by 22%, there remains a need to introduce this throughout the UK (Gardosi et al, 2013). Midwives and obstetricians should educate and emphasise the importance of fetal movements to women at each antenatal contact as a method of fetal surveillance and in order to increase compliance and understanding on the subject.