Biophysical profile for fetal assessment in high risk pregnancies

Lalor JG, Fawole B, Alfirevic Z, Devane D

Published Online:

April 18, 2012

Not enough evidence to support use of biophysical profile (BPP) for the assessment of fetal well-being in high-risk pregnancies.

Monitoring the baby's well-being in the uterus in pregnancy is often undertaken using a cardiotocograph (CTG) machine. A CTG assesses the pattern of the baby's heartbeats alongside the size of the mother's contractions. However, this is not a very accurate test on its own. So monitoring the baby's movements has also been suggested as a useful addition to predict babies in difficulty. This is because a reduction in fetal movement sometimes precedes a baby's death. It is thought that if the oxygen supply to the baby through the afterbirth (placenta) is insufficient, the baby responds by moving less often. As fetal movement patterns may vary considerably, multiple fetal activities might be a better predictor of poor outcome. Consequently, the biophysical profile (BPP) and modified biophysical profile (MBPP) have been introduced. The BPP uses ultrasound to assess 1) fetal movement, 2) tone, 3) breathing and 4) the amniotic fluid volume that surrounds the baby. In addition, the baby's heartbeat is monitored over a 20-minute period using a CTG machine. This produces a paper tracing of the baby's heart rate, the mother's contractions and when the baby moves. Sometimes a modified BPP is used first (MBPP), involving the CTG trace and the amniotic fluid volume only. If this indicates a possible abnormality, then the full BPP is used. This review of trials compared the BPP (or MBPP) with conventional monitoring (CTG only) on pregnancy outcome in high-risk pregnancies. Five trials involving 2974 women with pregnancies with a high risk of poorer fetal outcome were found. There was no difference between the groups in the number of babies that died, nor in the number of babies who had low Apgar scores. However, although the number of women involved was small, the BPP was associated with a significant increase in induction and caesarean section. However, the data are insufficient to reach a conclusion about the benefit or otherwise of the BPP as a test of fetal wellbeing.

Abstract (click to read)

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).

We updated the search of the Cochrane Pregnancy and Childbirth Group's Trials Register (10 January 2012) and added the results to the awaiting classification section.

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.

[Note: The three citations in the awaiting classification section of the review may alter the conclusions of the review once assessed.]

This record should be cited as:

Lalor JG, Fawole B, Alfirevic Z, Devane D. Biophysical profile for fetal assessment in high risk pregnancies. Cochrane Database of Systematic Reviews 2008, Issue 1. Art. No.: CD000038. DOI: 10.1002/14651858.CD000038.pub2

Assessed as up to date:

November 9, 2007

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Primary Review Group:

Pregnancy and Childbirth Group

Health topics:

Pregnancy & childbirth > Fetal assessment before labour > Impaired fetal growth & well-being

Cochrane Summaries^beta

Independent high-quality evidence for health care decision making

Biophysical profile for fetal assessment in high risk pregnancies

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