Friday, 5 February 2010

Quality improvements to antenatal screening for Down syndrome and other conditions - a review

The National Screening Unit of the Ministry of Health is implementing quality improvements to antenatal screening for Down syndrome and other conditions.  A key step in the quality improvement process is the introduction of two screening options, which are supported by new Guidelines for maternity providers, online education modules and consumer resources. 

From 8 February 2010, the two screening options available to New Zealand women are:

• First Trimester Combined Screening, which should be offered to all women who present early in pregnancy.  It includes
  • a first trimester maternal serum screening test, taken between 9 and 13 weeks and 6 days, and
  • a nuchal translucency scan (NT scan), carried out between 11 and 13 weeks and 6 days.

The maternal serum screening test is fully publicly funded, however generally a surcharge applies for NT scans.

The combined risk result will be calculated by the Laboratory and reported to the referring maternity provider. The risk is calculated from the NT scan results, the maternal serum screening test results, and other factors such as maternal age and weight, gestation and family history. This is a change in practice from the reporting risk based on the NT scan results alone – the incorporation of serum results significantly increase the sensitivity and specificity of screening.

• Second Trimester Maternal Serum Screening, which should be offered to all women who present after 14 and before 20 weeks, or who have not completed first trimester combined screening. This replaces the existing MSS2 triple test, is fully publicly funded, and includes four analytes. The risk result will be calculated by the Laboratory and reported to the referring maternity provider.

To assist health professionals to provide the new screening options in a nationally consistent and safe way, ensuring women are provided with the information to make an informed decision about screening, Guidelines for maternity providers offering antenatal screening for Down syndrome and other conditions in New Zealand, November 2009 have been developed. An update to radiology providers has also been distributed providing guidance on NT scanning requirements.

There are three consumer pamphlets designed to support discussions with women about antenatal screening for Down syndrome and other conditions. The pamphlets are available via http://www.healthed.govt.nz/, the local DHB health resource distributor or can be downloaded as a pdf from this website.  

Online education resources have been developed for health professionals offering services within the antenatal and newborn screening initiatives managed by the National Screening Unit. There are five modules available in workbook format via http://www.learnonline.health.nz/

1. Screening: Principles and Practice
2. Quality Improvement Measures for Antenatal Screening for Down Syndrome and Other Conditions
3. Universal Offer Antenatal HIV Screening Programme
4. Universal Newborn Hearing Screening and Early Intervention Programme
5. Newborn Metabolic Screening Programme.

A new laboratory form has been developed to support the ordering of these new screening tests.  Copies are available on request from LabPLUS 0800 522 7587 or Canterbury Health Laboratories 0800 843 522 or on this website.