FETAL ASSESSMENT SYNTHESIS

RESEARCH GAPS FROM COCHRANE REVIEWS

(Cochrane Library Issue 1, 2007)

The faces indicate the direction of findings in each review:

J Likely to be effective
K Both benefits and risks
?Uncertain or limited effect
L Likely to be ineffective or potentially harmful

Important research implications are more likely to arise from
?reviews with uncertain findings
or where
K  the risks and benefits are mixed.

Fetal assessment tests in pregnancy

L Biochemical tests of placental function (Neilson 2003)

Biochemical tests such as measurement of hormones are unlikely to be a major focus of research, although developments in laboratory techniques could stimulate further research in this area

?Biophysical profile versus fetal monitoring (usually cardiotocography) in high-risk pregnancies (Alfirevic 1996)

Need trials of biophysical profile in high-risk pregnancies that measure obstetric intervention, length of hospitalisation, serious neonatal morbidity and parents’ satisfaction

?Cardiotocography (Pattinson 1999)

Since CTG has become an integral part of antenatal care, a large enough study is now unlikely to be conducted

J Doppler ultrasound for fetal assessment in high-risk pregnancies (Neilson 1996)

L Routine Doppler ultrasound in pregnancy (Bricker 2000a) 

•   If another trial of Doppler ultrasound in low-risk pregnancies is conducted, it should be large enough to assess outcomes such as psychological effects on the mother, neonatal morbidity and longterm neurodevelopment and safety
• Such a trial should also assess the value of routine mid-pregnancy uterine Doppler ultrasound to predict pre-eclampsia, intrauterine growth restriction and other adverse outcomes 

?Fetal movement counting for assessment of fetal well-being (Mangesi 2007)

Need to determine the sensitivity and the specificity of fetal movement counting in detecting fetal compromise; its effectiveness in decreasing the perinatal mortality in high-risk and low-risk women; its acceptability to women; how easy it is for women; and the best fetal movement counting method

L Pelvimetry for fetal cephalic presentations at or near term (Pattinson 1997)

·        Further research should be directed towards defining whether there are specific clinical situations, for example breech presentations, in which x-ray pelvimetry can be shown to be of value. Newer methods of pelvimetry should be subjected to randomised trials to assess their value

·        Further trials of x-ray pelvimetry in cephalic presentations would be of value if large enough to assess the effect on perinatal mortality

J Ultrasound for fetal assessment in early pregnancy – routine versus selective (Neilson 1998)

·        Need larger RCTs of routine versus selective ultrasound which examine potential benefits of improved estimation of gestational age

·        Earlier detection of multiple pregnancies may allow better study of other, potentially useful, interventions

·        Need more data about the value of detection of fetal malformations as part of routine ultrasound examination programmes

·        Optimal timing of ultrasound could be addressed by a randomized controlled trial

K Routine ultrasound in late pregnancy (after 24 weeks gestation) (Bricker 2000b)

·        Further RCTs should assess the effects on both short and long term neonatal and childhood outcome and psychological effects (uncertainty, anxiety) of routine ultrasound in late pregnancy

·        Future research of late pregnancy ultrasound should include placental assessment

?Symphysis-fundal height measurement in pregnancy (Neilson 1998)

Requires a much larger trial than has been performed to date

Methods to facilitate tests of fetal wellbeing

L Fetal manipulation in conjunction with tests of fetal wellbeing (Tan 2001a)

·        No benefits of fetal manipulation have yet been demonstrated in trials

·        Not known if there are differences in outcome between different methods of manipulation

J Fetal vibroacoustic stimulation in conjunction with tests of fetal wellbeing (Tan 2001b)

·        Further RCTs should investigate not only the optimum intensity, frequency, duration and position of the vibroacoustic stimulation, but also the efficacy, safety and perinatal outcome of these stimuli in conjunction with cardiotocography and other tests of fetal well-being

·        These trials should be blinded, using mock stimulation, and outcomes such as fetal hearing impairment, loss of impaired neurological development, maternal satisfaction and maternal anxiety should also be assessed

?Maternal glucose administration for facilitating tests of fetal wellbeing (Tan 2001c)

No benefits of glucose administration have yet been demonstrated in trials, so this is unlikely be an active area for research

Fetal monitoring during labour

?Cardiotocography versus intermittent auscultation of fetal heart on admission to labour ward (Devane 2005)

Cochrane protocol, not yet covered in a Cochrane review

K Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour (Alfirevic 2006)

·        Need to further investigate causation and possible links between antenatal or intrapartum events, neonatal seizures and long-term neurodevelopmental outcome

·        It may be possible to follow up babies in RCTs included in this review to see if seizure reduction leads to long-term benefits.

·        Need to assess whether mobility and positions can reduce the already low incidence of neonatal seizures and improve psychological outcomes for women.

K Fetal electrocardiogram (ECG) plus/versus other methods of fetal monitoring during labour (Neilson 2006)

·        Need more information about the value of fetal ECG waveform monitoring in preterm fetuses in labour

·        Long term outcomes need to be measured

?Fetal pulse oximetry for fetal assessment in labour (East 2004)                 

·        Need further RCTs (ideally blinded) to address: dystocia; maternal satisfaction; long-term neurodevelopmental outcome of infants who exhibited nonreassuring fetal status in labour; and costs

·        [several more trials have recently been published and these are being incorporated in a update of this review which will be published shortly]

? Intrapartum fetal scalp lactate sampling for fetal assessment in the presence of a non-reassuring fetal heart rate trace (East 2006)

Cochrane protocol, not yet covered in a Cochrane review

?Near-infrared spectroscopy for fetal assessment during labour (Mozurkewich 2000)

No RCTs have been done - should NIRS technology prove to be reliable, a well-designed RCT of near-infrared spectroscopy with other methods of fetal surveillance will be needed

?Vibroacoustic stimulation for fetal assessment in labour in the presence of a nonreassuring fetal heart rate trace (East 2005)

No trials were located – assessing long-term neurodevelopmental disability would be difficult to power without a prohibitively large sample size. Other relevant outcomes include the number of additional tests performed to assess fetal well-being following identification of a non-reassuring CTG, and operative birth rates

REFERENCES

Alfirevic Z, Neilson JP. Biophysical profile for fetal assessment in high risk pregnancies. The Cochrane Database of Systematic Reviews 1996, Issue 1

Alfirevic Z, Devane D, Gyte GML. Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour. Cochrane Database of Systematic Reviews 2006, Issue 3.

Bricker L, Neilson JP. Routine Doppler ultrasound in pregnancy. Cochrane Database of Systematic Reviews 2000, Issue 2 (2000a)

Bricker L, Neilson JP. Routine ultrasound in late pregnancy (after 24 weeks gestation). The Cochrane Database of Systematic Reviews 2000, Issue 1 (2000b)

Devane D, Lalor JG, Daly S, McGuire W. Cardiotocography versus intermittent auscultation of fetal heart on admission to labour ward for assessment of fetal wellbeing. (Protocol) The Cochrane Database of Systematic Reviews 2005, Issue 1.

East CE, Chan FY, Colditz PB. Fetal pulse oximetry for fetal assessment in labour. The Cochrane Database of Systematic Reviews 2004, Issue 4

East CE, Leader LR, Colditz PB, Henshall NE. Intrapartum fetal scalp lactate sampling for fetal assessment in the presence of a non-reassuring fetal heart rate trace. (Protocol) Cochrane Database of Systematic Reviews 2006, Issue 4

East CE, Smyth R, Leader LR, Henshall NE, Colditz PB, Tan KH. Vibroacoustic stimulation for fetal assessment in labour in the presence of a nonreassuring fetal heart rate trace. The Cochrane Database of Systematic Reviews 2005, Issue 2

Mangesi L, Hofmeyr GJ. Fetal movement counting for assessment of fetal wellbeing. Cochrane Database of Systematic Reviews 2007, Issue 1

Mozurkewich E, Wolf FM. Near-infrared spectroscopy for fetal assessment during labour. The Cochrane Database of Systematic Reviews 2000, Issue 3.

Neilson JP. Biochemical tests of placental function for assessment in pregnancy. The Cochrane Database of Systematic Reviews 2003, Issue 2.

Neilson JP, Alfirevic Z. Doppler ultrasound for fetal assessment in high risk pregnancies. The Cochrane Database of Systematic Reviews 1996, Issue 2

Neilson JP. Fetal electrocardiogram (ECG) for fetal monitoring during labour. The Cochrane Database of Systematic Reviews 2006, Issue 3.

Neilson JP. Symphysis-fundal height measurement in pregnancy. The Cochrane Database of Systematic Reviews 1998, Issue 1.

Neilson JP. Ultrasound for fetal assessment in early pregnancy. The Cochrane Database of Systematic Reviews 1998, Issue 4

Pattison N, McCowan L. Cardiotocography for antepartum fetal assessment. The Cochrane Database of Systematic Reviews 1999, Issue 1.

Pattinson RC, Farrell E. Pelvimetry for fetal cephalic presentations at or near term. The Cochrane Database of Systematic Reviews 1997, Issue 2

Tan KH, Sabapathy A. Fetal manipulation for facilitating tests of fetal wellbeing. The Cochrane Database of Systematic Reviews 2001, Issue 4. (2001a)

Tan KH, Smyth R. Fetal vibroacoustic stimulation for facilitation of tests of fetal wellbeing. The Cochrane Database of Systematic Reviews 2001, Issue 1. (2001b)

Tan KH, Sabapathy A. Maternal glucose administration for facilitating tests of fetal wellbeing. Cochrane Database of Systematic Reviews 2001, Issue 4 (2001c)