Free Oxford Handbook of Midwifery by Janet Medforth, Sue Battersby, Maggie Evans, Beverley Marsh, Angela Walker Page B

screen result is 1:10–1:210.
If the result is 1:210+, then advise the woman that her screen result is low risk.
Provide information about what the test involves, how the risk is calculated and what is meant by a risk factor.
There needs to be understanding that low risk is not ‘no risk’ and that any woman could be the ‘one’ of the 1:800.
Explain the nature of the diagnostic test and the risk of miscarriage from this test (1%).
Discuss options following diagnosis of Down’s syndrome, and provide non-directive support to the decision to choose termination or continuation of the pregnancy.
Further reading
National Institute for Health and Clinical Excellence (2008). Antenatal care: Routine care for the healthy pregnant mother. Clinical guideline 62. London: NICE. Available at: M www.nice.org. uk/cg62.
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Group B haemolytic streptococcus
Group B haemolytic streptococcus (GBS) is one of a number of common bacteria found in the gut of 30% of men and women. It is estimated that 25% of women carry this organism in the vaginal tract with no ill effect. Its significance is that it can be transmitted to the baby during delivery and is the most common cause of fatal bacterial infection in the early neonatal period.
Incidence
In the UK, approximately 1:2000 babies annually acquire GBS infection, pre- senting with septicaemia, pneumonia, or meningitis. A UK survey in 2001 identified 376 cases of early-onset GBS disease, 39 of which were fatal.
Presentation
There are two ways in which the infection will present:
90% of the infections are early onset, and 70% of babies are symptomatic at birth
• 10% are late onset, occurring after 48h and up to 3 months after birth.
Screening
There is little organized antenatal screening for GBS carriage in the UK at present and most maternity units rely on risk factor estimation to iden- tify carriers and situations where the infection may be transmitted to the neonate.
Risk factors
Previous baby affected by GBS.
GBS bacteriuria detected in the present pregnancy.

Pre-term labour.
Prolonged rupture of the membranes.
Pyrexia during labour.
Intrapartum antibiotic prophylaxis (IAP) is offered to women who have any of these risk factors. This approach differs from that in the USA, where all pregnant women are offered bacteriological screening at 35–37 weeks’ gestation. This involves taking vaginal and rectal swabs, and all women who carry GBS are offered IAP. This results in 27% of all pregnant women being offered IAP during labour and a reduction in early onset GBS disease of 86%.
Royal College of Obstetrics and Gynaecology recommendations
The Royal College of Obstetrics and Gynaecology (RCOG) 1 has made the following recommendations in the absence of clinical trials and recent data on the prevalence of GBS carriage in the UK.
Routine antenatal screening is not recommended.
Antenatal treatment with penicillin is not recommended if GBS is detected incidentally.
IAP should be considered if GBS is detected incidentally.
There is no good evidence to support IAP in women who carried GBS in a previous pregnancy.
IAP should be offered to women who had a previous baby with GBS disease.
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The argument for IAP is stronger in the presence of two or more risk factors.
IAP should be offered, after discussion, to women with GBS bacteriuria.
Antibiotic prophylaxis is not required for women undergoing elective caesarean section in the absence of labour and with intact membranes.
Antibiotic prophylaxis is unnecessary for women with pre-term rupture of membranes unless they are in established labour.
Penicillin should be administered as soon as possible after the onset of labour. Clindamycin should be given in the event of penicillin allergy.
1 Royal College of Obstetrics and Gynaecology (2007). Preventing Group B Streptococcus Infection in Newborn Babies . London: RCOG.
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Sickle cell anaemia
Haemoglobin is a