A simplified fetal biophysical profile

Impact of maternal fasting on fetal well-being parameters and fetal-neonatal outcome: a case-control study

OBJECTIVE

To assess the impact of maternal fasting on fetal well-being parameters and neonatal outcome.

METHODS

Two-hundred ten healthy women with singleton uncomplicated pregnancies at 36-40 weeks' gestation who had fasted for 12-16 h were defined as the study group with 240 healthy non-fasted pregnant women matched for age, parity and gestational age were defined as the control group. Both groups were subjected to tests of fetal well-being in the form of non-stress test (NST), modified biophysical profile and Doppler indices of the umbilical and middle cerebral arteries (MCA). Women were followed-up till delivery to record the obstetric outcome.

RESULTS

There was no significant difference between the two groups regarding the reactivity of NST, modified biophysical scores, Doppler indices of the umbilical and MCA (resistive index, pulsatility index and systolic/diastolic ratio) and the cerebroplacental ratio (p > 0.05). There was no significant difference between the two groups regarding the gestational age at delivery, mode of delivery, neonatal weight, 5-min Apgar scores and admission to neonatal intensive care unit (p > 0.05).

CONCLUSIONS

Short-term maternal fasting has no deleterious effect on fetal well-being parameters or neonatal outcome. Pregnant women who desire fasting, should be reassured regarding the health of their babies.

Fetal vibroacoustic stimulation for facilitation of tests of fetal wellbeing

BACKGROUND

Acoustic stimulation of the fetus has been suggested to improve the efficiency of antepartum fetal heart rate testing.

OBJECTIVES

To assess the advantages and disadvantages of the use of fetal vibroacoustic stimulation in conjunction with tests of fetal wellbeing.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2013).

SELECTION CRITERIA

All published and unpublished randomised controlled trials assessing the merits of the use of fetal vibroacoustic stimulation in conjunction with tests of fetal wellbeing.

DATA COLLECTION AND ANALYSIS

All review authors independently extracted data and assessed trial quality. Authors of published and unpublished trials were contacted for further information.

MAIN RESULTS

Altogether 12 trials with a total of 6822 participants were included. Fetal vibroacoustic stimulation reduced the incidence of non-reactive antenatal cardiotocography test (nine trials; average risk ratio (RR) 0.62, 95% confidence interval (CI) 0.48 to 0.81). Vibroacoustic stimulation compared with mock stimulation evoked significantly more fetal movements when used in conjunction with fetal heart rate testing (one trial, RR 0.23, 95% CI 0.18 to 0.29).

AUTHORS' CONCLUSIONS

Vibroacoustic stimulation offers benefits by decreasing the incidence of non-reactive cardiotocography and reducing the testing time. Further randomised trials should be encouraged to determine not only the optimum intensity, frequency, duration and position of the vibroacoustic stimulation, but also to evaluate the efficacy, predictive reliability, safety and perinatal outcome of these stimuli with cardiotocography and other tests of fetal wellbeing.

Reducing stillbirths: screening and monitoring during pregnancy and labour

BACKGROUND

Screening and monitoring in pregnancy are strategies used by healthcare providers to identify high-risk pregnancies so that they can provide more targeted and appropriate treatment and follow-up care, and to monitor fetal well-being in both low- and high-risk pregnancies. The use of many of these techniques is controversial and their ability to detect fetal compromise often unknown. Theoretically, appropriate management of maternal and fetal risk factors and complications that are detected in pregnancy and labour could prevent a large proportion of the world's 3.2 million estimated annual stillbirths, as well as minimise maternal and neonatal morbidity and mortality.

METHODS

The fourth in a series of papers assessing the evidence base for prevention of stillbirths, this paper reviews available published evidence for the impact of 14 screening and monitoring interventions in pregnancy on stillbirth, including identification and management of high-risk pregnancies, advanced monitoring techniques, and monitoring of labour. Using broad and specific strategies to search PubMed and the Cochrane Library, we identified 221 relevant reviews and studies testing screening and monitoring interventions during the antenatal and intrapartum periods and reporting stillbirth or perinatal mortality as an outcome.

RESULTS

We found a dearth of rigorous evidence of direct impact of any of these screening procedures and interventions on stillbirth incidence. Observational studies testing some interventions, including fetal movement monitoring and Doppler monitoring, showed some evidence of impact on stillbirths in selected high-risk populations, but require larger rigourous trials to confirm impact. Other interventions, such as amniotic fluid assessment for oligohydramnios, appear predictive of stillbirth risk, but studies are lacking which assess the impact on perinatal mortality of subsequent intervention based on test findings. Few rigorous studies of cardiotocography have reported stillbirth outcomes, but steep declines in stillbirth rates have been observed in high-income settings such as the U.S., where cardiotocography is used in conjunction with Caesarean section for fetal distress.

CONCLUSION

There are numerous research gaps and large, adequately controlled trials are still needed for most of the interventions we considered. The impact of monitoring interventions on stillbirth relies on use of effective and timely intervention should problems be detected. Numerous studies indicated that positive tests were associated with increased perinatal mortality, but while some tests had good sensitivity in detecting distress, false-positive rates were high for most tests, and questions remain about optimal timing, frequency, and implications of testing. Few studies included assessments of impact of subsequent intervention needed before recommending particular monitoring strategies as a means to decrease stillbirth incidence. In high-income countries such as the US, observational evidence suggests that widespread use of cardiotocography with Caesarean section for fetal distress has led to significant declines in stillbirth rates. Efforts to increase availability of Caesarean section in low-/middle-income countries should be coupled with intrapartum monitoring technologies where resources and provider skills permit.

Biophysical profile for fetal assessment in high risk pregnancies

BACKGROUND

A biophysical profile (BPP) includes ultrasound monitoring of fetal movements, fetal tone and fetal breathing, ultrasound assessment of liquor volume with or without assessment of the fetal heart rate. The BPP is performed in an effort to identify babies that may be at risk of poor pregnancy outcome, so that additional assessments of wellbeing may be performed, or labour may be induced or a caesarean section performed to expedite birth.

OBJECTIVES

To assess the effects of the BPP when compared with conventional monitoring (CTG only or MBPP) on pregnancy outcome in high-risk pregnancies.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (October 2007), CENTRAL (The Cochrane Library 2006, Issue 4), MEDLINE (1966 to November 2006), EMBASE (1974 to November 2006) and CINAHL (1980 to November 2006).

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials involving a comparison of fetal BPP with other forms of antepartum fetal assessment in women with high-risk pregnancies.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed eligibility, quality and extracted data.

MAIN RESULTS

We included five trials, involving 2974 women. Most trials were not of high quality. Although the overall incidence of adverse outcomes was low, available evidence from randomised controlled trials does not support the use of BPP as a test of fetal wellbeing in high-risk pregnancies. We found no significant differences between the groups in perinatal deaths (relative risk (RR) 1.33, 95% confidence interval (CI) 0.60 to 2.98) or in Apgar score less than seven at five minutes (RR 1.27, 95% CI 0.85 to 1.92). Combined data from the two high-quality trials suggest an increased risk of caesarean section in the BPP group RR 1.60, 95% CI 1.05 to 2.44, n = 280, interaction test P = 0.03. However, the number of participating women was relatively small (n = 280). Therefore, additional evidence is required in order to be definitive regarding the efficacy of this test in high-risk pregnancies. Furthermore, the impact of the BPP on other interventions, length of hospitalisation, serious short-term and long-term neonatal morbidity and parental satisfaction requires further evaluation.

AUTHORS' CONCLUSIONS

At present, there is insufficient evidence from randomised trials to support the use of BPP as a test of fetal wellbeing in high-risk pregnancies.

Using fetal acoustic stimulation to shorten the biophysical profile

PURPOSE

To determine whether fetal acoustic stimulation can decrease the time required to achieve a reassuring biophysical profile.

METHODS

Patients scheduled for a biophysical profile were prospectively assigned to study and control groups. The study group received 3 seconds of acoustic stimulation if fetal breathing, tone, or movement were not present during the first 5 minutes of the study. The biophysical profile was completed in the standard fashion, for both groups.

RESULTS

A total of 870 patients were enrolled (458 control, 412 with stimulation). The fetal acoustic stimulation group had decreased testing time (3 minutes) and fewer non-reassuring tests (5%). The fetal acoustic stimulation group had fewer studies without breathing, potentially reducing the need for further testing or intervention.

CONCLUSIONS

Fetal acoustic stimulation can be used to decrease the biophysical profile testing time and to reduce the number of non-reassuring tests.

The neonatal diaphragmatic crura are hypertrophied: a necessary preparation for the first breath?

OBJECTIVE

To sonographically show that the neonatal crura are markedly hypertrophied.

METHODS

Fifty patients in each of 2 groups, ages 0 to 2 months and 18 to 40 years, were randomly chosen from patients who recently underwent abdominal sonography. A single longitudinal plane of a section was used to measure both the anteroposterior diameter of the aorta and the diaphragmatic crus. The ratios of these were compared in the 2 groups.

RESULTS

A significant difference was shown between the sizes of the diaphragmatic crura of the neonate and the adult when the aorta was used as an internal standard of size variability. The mean ratio of the aorta to the right crus in neonates was 2.95, and in young adults it was 1.04 (P < .0001).

CONCLUSIONS

The neonatal crura are hypertrophied at birth, likely to allow the markedly atelectatic and fluid-filled lungs to fully expand in relatively few breaths.

Fetal vibroacoustic stimulation for facilitation of tests of fetal wellbeing

BACKGROUND

Acoustic stimulation of the fetus has been suggested to improve the efficiency of antepartum fetal heart rate testing.

OBJECTIVES

The objective of this review was to assess the merits or adverse effects of the use of fetal vibroacoustic stimulation in conjunction with tests of fetal wellbeing.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register. Date of last search: October 2000.

SELECTION CRITERIA

All published and unpublished randomized controlled trials assessing the merits of the use of fetal vibroacoustic stimulation in conjunction with tests of fetal wellbeing.

DATA COLLECTION AND ANALYSIS

Both reviewers independently extracted data and assessed trial quality. Authors of published and unpublished trials were contacted for further information.

MAIN RESULTS

A total of seven trials with a total of 4325 participants were included. Fetal vibroacoustic stimulation reduced the incidence of non-reactive antenatal cardiotocography test (odds ratio (OR) 0.61, 95% confidence interval (CI) 0.49-0.75) and reduced the overall mean cardiotocography testing time (weighted mean difference (WMD) -4.55 minutes, 95% CI -5.96 minutes to -3.14 minutes). Vibroacoustic stimulation evoked more than mock stimulation when used in conjunction with fetal heart rate testing (OR 0.08, 95% CI 0.06-0.12).

REVIEWER'S CONCLUSIONS

Vibroacoustic stimulation offers benefits by decreasing the incidence of non-reactive cardiotocography and reducing the testing time. Further randomized trials should be encouraged to determine not only the optimum intensity, frequency, duration and position of the vibroacoustic stimulation, but also to evaluate the efficacy, predictive reliability, safety and perinatal outcome of these stimuli with cardiotocography and other tests of fetal wellbeing.

Biophysical profile for fetal assessment in high risk pregnancies

BACKGROUND

Biophysical profile usually includes ultrasound monitoring of fetal movements, fetal tone and fetal breathing, ultrasound assessment of amniotic fluid volume and assessment of fetal heart rate by electronic monitoring.

OBJECTIVES

The objective of this review was to assess the effects of biophysical profile tests on pregnancy outcome in high risk pregnancies.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth trials register. Date of last search: October 1998.

SELECTION CRITERIA

Randomised trials comparing fetal biophysical profile with other forms of fetal assessment in women with high risk pregnancies.

DATA COLLECTION AND ANALYSIS

Trial quality was assessed.

MAIN RESULTS

Four studies were included. Most trials were not of high quality. No difference was found between biophysical profile and other forms of fetal assessment over a range of fetal and neonatal measures.

REVIEWER'S CONCLUSIONS

At present, there is not enough evidence from randomised trials to evaluate the use of biophysical profile as a test of fetal well-being in high risk pregnancies.