Clinical Practice Guidelines Antenatal care - Module I

8. Maternal health screening

Page last updated: 02 April 2013

This section discusses the evidence for offering women tests during the first trimester.1 Discussion is included about tests for human immunodeficiency virus (HIV), chlamydia, syphilis, rubella, hepatitis B, hepatitis C, asymptomatic bacteriuria, bacterial vaginosis and vitamin D deficiency. Recommendations are based on evidence about the diagnostic accuracy of available tests, the effectiveness of interventions to prevent mother-to-child transmission of infection or other effects on the unborn baby, and the availability of treatments to improve the health and wellbeing of the mother. For some conditions, testing is recommended for all women. For others, testing is only recommended for women who may be at higher risk.

For notifiable infections (HIV, hepatitis B, hepatitis C, rubella, syphilis, chlamydia), diagnoses are reported to the National Notifiable Diseases Surveillance System (NNDSS) and analysis of trends in jurisdictions and groups at risk is possible (although data quality varies for the different conditions and reporting of Indigenous status is incomplete in some States and for some conditions). Evidence on the prevalence and incidence of other conditions is generally from observational studies and may not be representative of the Australian population or
groups within the population. While incidence or prevalence data are not always available, each chapter includes a brief discussion that aims to give health professionals an understanding of the likelihood that women in their community will be affected.

Considerations before testing

Before tests are carried out, it is essential that:
  • women are informed that it is their choice to have tests;
  • women are able to give informed consent — verbal discussion should cover the harms and benefits of testing and associated treatments and be supported by appropriate resources (eg written materials, audio or video);
  • women have opportunities to ask questions about tests and treatments;
  • women are reassured that test results remain confidential;
  • discussions about consent are documented by the health professional involved;
  • women who decline testing are offered the opportunity to discuss any concerns they may have without being coerced to reconsider the test; and
  • there are processes for follow-up of women with a positive test result and their babies.

Considerations after a positive test result

  • Referral for specialist care — For some conditions, such as HIV and hepatitis C, specialist involvement will be required.
  • Psychosocial support — Receiving a diagnosis of a condition that may affect pregnancy and/or the health of the unborn baby can be distressing, particularly if there are no interventions that can change outcomes. Women should be given information about available supports and assisted to access these.
  • Sexually transmitted infections — Partner testing and contact tracing are additional considerations.
  • Blood-borne infections — Specific supports are likely to be required for women identified as using intravenous drugs.

Testing in rural and remote areas

It is acknowledged that in Australia access to tests may vary (eg due to distance from pathology services), storing tests and samples appropriately may be challenging (eg due to high temperatures or humidity) and there may be difficulties in recalling women to receive test results. In these situations, resources should be focussed on responding to identified local needs (eg ensuring that tests are available to identify conditions that are highly prevalent).

Table 8.1: Summary of advice on offering certain tests in the first trimester2

Screening offered to all woman

Condition Test(s) Follow-up*
HIV EIA and Western blot
Blood-based rapid tests
Antiretroviral treatment in pregnancy reduces risk of transmission
Specialist care and psychosocial support for the woman are required
Hepatitis B Blood test for HbsAg Vaccination of newborn reduces risk of infection
Specialist care and psychosocial support for the woman are required
Rubella Blood test for rubella antibody Vaccination after birth protects future pregnancies
Inadvertent vaccination in early pregnancy is highly unlikely to harm the baby
Syphilis Treponemal EIA tests
Onsite tests
Treatment benefits mother and prevents congenital syphilis
Psychosocial support, partner testing and contact tracing required
Asymptomatic bacteriuria Midstream urine culture Treatment reduces risk of pyelonephritis

Screening offered to woman at higher risk

Condition Offer test to: Test(s) Follow-up*
Hepatitis C Women with a history of:
  • Intravenous drug use
  • Tattoos or body piercing
  • Needle sharing
  • Incarceration
  • Receipt of blood products or invasive procedures overseas or before 1990 in Australia
Blood test for hepatitis antibody
RNA test if antibodies detected
No interventions available to prevent transmission
Specialist care and psychosocial support for the woman are required
Chlamydia Women younger than 25 yrs
All pregnant women in areas of high prevalence
First pass urine
Antigen detection test
Nucleic acid amplification test
Treatment may reduce the risk of preterm birth, premature rupture of the membranes and low birth weight
Psychosocial support, partner testing and contact tracing required
Asymptomatic bacterial vaginosis Women with a previous preterm birth High vaginal swab
Amsel’s criteria
Nugent’s criteria
Early treatment (<20wks) may reduce risk of premature rupture of the membranes and low birth weight
Vitamin D deficiency Women considered to be at risk Blood test for serum 25-OHD Supplementation may be beneficial for women at high risk of deficiency
Notes: * Considerations for follow-up and support of women with a positive test result are included on page 99.
EIA=enzyme immunoassay; HbsAg=hepatitis B surface antigen; 25-OHD=25-hydroxyvitamin D; RNA=ribonucleic acid

1 Systematic literature reviews were not conducted for all tests offered as part of antenatal care. Table 6.1 (page 37) outlines tests that should be offered at the first antenatal visit based on the systematic reviews, guidance from NICE (2008) and relevant Australian guidelines.

2 Screening tests are offered in the context of engagement and consultation with women. When conducting screening tests, health professionals must use standard precautions for infection prevention and control.