UK National Screening Committee
Antenatal screening for asymptomatic bacteriuria
8th February 2017
Aim
1. To ask the UK National Screening Committee (UK NSC) to make a recommendation based on
the evidence presented in this document, whether antenatal screening for asymptomatic
bacteriuria (ASB) meets the UK NSC criteria to support the introduction of a population
screening programme.
Current recommendation
2. The previous, 2012, review of antenatal screening for ASB concluded that a systematic
antenatal screening programme for ASB did not meet the UK NSC criteria and should
therefore not be introduced.
This recommendation was based on the Meads Review, published in 2011 that highlighted
key uncertainties in; the prevalence of ASB, the impact screening has on pregnant women
developing pyelonephritis (kidney infection), the optimum test and its timing and frequency
during pregnancy and the optimal treatment strategy.
3. However the Committee were conscious of the NICE guidance embedded in antenatal care
where routine screening for ASB is offered in early pregnancy. The Committee were
reluctant to recommend the cessation of the long standing practice of screening ASB in the
first trimester as recommended by NICE, as the review found there were no reports of
harms from this practice.
In addition there is an overlap between the NICE recommendations in this area and other
disease areas. This includes NICE and Royal College of Obstetricians and Gynaecologists
(RCOG) recommendations on the management of incidentally detected GBS carriage.
Review
4. This review was undertaken by Solutions for Public Health, in accordance with the triennial
review process. https://legacyscreening.phe.org.uk/asymptomaticbacteriuria. Expert input
was provided by Professor Catherine Peckham.
5. This review focuses on three UK NSC criteria (1, the condition, 4, the test and 9, the
intervention). The review sought to evaluate the published evidence relating to key
questions identified as areas of uncertainty from the previous review.
6. The conclusion of this review is to uphold the UK NSC recommendation that a whole
population screening programme for antenatal screening of asymptomatic bacteriuria
should not be introduced in the UK. The key reasons are:
a. There was no new evidence available on how many pregnant women develop
asymptomatic bacteriuria in the UK.
One study of pregnant women in the Netherlands found that adverse outcomes (for
example pyelonephritis and preterm birth) for women with ASB were lower than
expected compared to previously published figures. This lead to the study being
stopped early. In the absence of updated information on how many pregnant
women have ASB or pyelonephritis in the UK, it is uncertain whether the same
results would be found in a population of pregnant women in the UK. Criterion 1 not
met
b. There was no new evidence on the timing of testing for ASB during pregnancy or the
frequency of testing. The most effective way of screening pregnant women for ASB
remains uncertain. Criterion 4 not met
c. Evidence from a recent trial (an RCT) found no difference between treated and
untreated women with ASB for risk of pyelonephritis and delivery of the baby before
34 weeks. There was also no difference between treated and untreated women for a
range of other maternal and neonatal outcomes. This contrasts with the evidence
reported in the 2011 UK NSC review, which suggested that the risk of pyelonephritis
is reduced with antibiotics compared to placebo or no treatment (by approximately
75%). Because of the different results and limitations with both studies the use of
antibiotics for ASB in pregnant women to prevent adverse outcomes is uncertain.
2
d. A systematic review on the length of treatment for ASB found no difference in cure
rates, recurrence of ASB, pyelonephritis or preterm birth rates between a short
course or single dose of antibiotics. However, when only good quality studies were
included in the analysis they suggested that a short course of antibiotics may lead to
a better outcome (based on limited data). A single dose of antibiotics was associated
with fewer side effects. Criterion 11 not met
Consultation
7. A three month consultation was hosted on the UK NSC website. Direct emails were sent to
stakeholders of whom 17 organisations were contacted directly. Annex A
8. Responses were received from the following 5 stakeholders; Royal College of Paediatrics and
Child Health (RCPCH), Members of the British Society for Antimicrobial Chemotherapy
(BSAC), British Infection Association, British Maternal and Fetal Medicine Society and
Committee Royal College of Obstetricians and Gynaecologists (RCOG). All comments are in
Annex B, below.
9. The responses indicated broad agreement with the review’s recommendations.

One stakeholder raised the issue that not recommending screening for ASB could be
perceived as a contradiction of the recommendation made by antenatal care NICE
clinical guideline 62 in relation to screen for pre-eclampsia — ‘Blood pressure
measurement and urinalysis for protein should be carried out at each antenatal visit
to screen for pre-eclampsia. [2008]’.
However, the recommendation proposed by this review is limited to antenatal
screening for ASB and the review did not look at evidence in relation to incidental
detection for the condition related to screening for other conditions that are outside
the remit this review.

Some consultees raised issues relating to the conduct of the review, interpretation
of individual papers and overall analysis. These were addressed by the reviewer and
alterations made to the evidence review where appropriate.. See Annex B
3
Recommendation
The Committee is asked to reaffirm the following recommendation:
Screening for asymptomatic bacteriuria is offered as part of routine antenatal care packages.
The UK NSC is concerned about the lack of knowledge about the current prevalence of
asymptomatic bacteriuria, the impact of screening on pyelonephritis as a whole, the
optimum test, its timing and frequency during the pregnancy and the optimum treatment
strategy. However current practice overlaps with guidance in other areas and the
consequences of recommending withdrawal of screening are uncertain at this point
Based on the 20 UK NSC criteria set to recommend a population screening programme,
evidence was appraised against the following three criteria:
Criteria
Met /
Not met
The condition should be an important health problem as judged by its
frequency and/or severity. The epidemiology, incidence, prevalence and
natural history of the condition should be understood, including the
1
development from latent to declared disease and/or there should be robust
evidence about the association between the risk or disease marker and serious
treatable disease..
Not met

The Condition
The Test
4 There should be a simple, safe, precise and validated screening test
Not met

The intervention
There should be an effective intervention for patients identified through
screening, with evidence that intervention at a pre-symptomatic phase leads to
better outcomes for the screened individual compared with usual care.
9 Evidence relating to wider benefits of screening, for example those relating to
family members, should be taken into account where available. However,
where there is no prospect of benefit for the individual screened then the
screening programme shouldn’t be further considered.
4
Not met

Annex A
List of organisations contacted:
1. Antibiotic Research
2. Association for Improvements in the Maternity Services
3. British Association of Perinatal Medicine
4. British Infection Association
5. British Maternal & Fetal Medicine Society
6. British Society for Antimicrobial Chemotherapy
7. MBRRACE-UK
8. Group B Strep Support
9. Maternity Action
10. National Childbirth Trust
11. Royal College of General Practitioners
12. Royal College of Midwives
13. Royal College of Nursing
14. Royal College of Obstetricians and Gynaecologists
15. Royal Society for Public Health
16. Tommy's
17. United Kingdom Sepsis Group
5
Annex B
Consultation comments
Note that the five consultation comments are listed in the table below, grouped by the section of the draft review document to which they refer.
Comment
number
Stakeholder Name,
Consented for names
to be published:
Yes
NO
Section
and / or
page
number
Text or issue
to which
comments
relate
Comment
Please use a new row for each comment and add extra rows as required.
Comment
number
Stakeholder Name,
Consented for names
to be published:
Yes
Section
and / or
page
number
Text or issue
to which
comments
relate
Comment
Please use a new row for each comment and add extra rows as required.
NO
1.
Royal College of
Paediatrics and Child
Health
general
Our commenter expressed their hope that future research and systematic reviews apply additional neonatal
outcomes to preterm birth, e.g. neonatal infection.
Yes
2.
Members of the British
Society for
Antimicrobial
Chemotherapy (BSAC)
Members of the British Society for Antimicrobial Chemotherapy (BSAC) have no comments to this consultation
on antenatal screening for Asymptomatic Bacteriuria.
3.
Our organisation supports the publication of this document.
Anna Goodman
(Guidelines Secretary)
British Infection
Association
Yes
4.
The BMFMS supports the conclusions of this review
David Howe
(Committee Member);
British Maternal and
Fetal Medicine Society
Yes
5.
General
Andrew Thomson &
Manish Gupta Cochairs, RCOG Guidelines
General
It is unclear from the text as to where the routine practice of urine dipstick at each antenatal visit sits in context
of screening. Does the document indicate that there is no need to dipstick urine at each antenatal check-up? Will
urine dipstick be indicated only if there are UTI symptoms, and not be done as a universal screen?
Could authors be a little more specific in their recommendations? Should be clarified as mentioned in the NICE
7
Comment
number
Stakeholder Name,
Consented for names
to be published:
Yes
Section
and / or
page
number
Text or issue
to which
comments
relate
Comment
Please use a new row for each comment and add extra rows as required.
NO
Committee Royal
College of Obstetricians
and Gynaecologists
guidance:
1.9.2.1 Blood pressure measurement and urinalysis for protein should be carried out at each antenatal visit to
screen for pre-eclampsia. [2008]
YES
5.1
Andrew Thomson &
Manish Gupta Cochairs, RCOG Guidelines
Committee Royal
College of Obstetricians
and Gynaecologists
Page 3 –
First
paragraph
It can also
cause
premature
birth and
stillbirth.
Final sentence “It can...” What can? ASB or pyelonephritis. I think you mean pyelonephritis.
Page 3
Point 2
A study in the
Netherlands
found that
ASB in
pregnancy
was less
harmful than
expected
How less harmful? – it may be better to inform briefly here.
Page 3
Point 4
But when
only good
quality
studies were
included
Again what better outcome – please inform briefly here
YES
5.2
Andrew Thomson &
Manish Gupta Cochairs, RCOG Guidelines
Committee Royal
College of Obstetricians
and Gynaecologists
YES
5.3
Andrew Thomson &
Manish Gupta Cochairs, RCOG Guidelines
Committee Royal
8
Comment
number
Stakeholder Name,
Consented for names
to be published:
Yes
Section
and / or
page
number
Text or issue
to which
comments
relate
Comment
Please use a new row for each comment and add extra rows as required.
NO
College of Obstetricians
and Gynaecologists
YES
results
suggested
that a short
course of
antibiotics
may lead to a
better
outcome
9