Pre-Conception Genetic Screening

Having a genetically inherited rare disorder in the family can raise questions and fears. A genetic disease may appear in a child if a faulty gene is passed on from the parents, and this may occur whether or not either parent shows signs of the disease. Good information is the key to planning for your future family.

Rare disorders, fertility and having children

Foetal ultrasoundAntenatal screening and diagnostic tests are available in New Zealand, such as nuchal translucency screening, chorionic villus sampling and amniocentisis. These can be performed to predict risk factors and test for genetic abnormalities. These tests can detect some congenital irregularities but there is no test that checks for all possible abnormalities.

Screening tests assess whether a baby is at a high or low risk of having a particular condition. Diagnostic tests can identify babies who actually have a particular condition. Counselling should be available to both parents before any genetic testing is undertaken, and after if the test is positive for an abnormality.

Pre-implantation genetic screening

Pre-implantation genetic screening (PGS) is an in vitro (IVF) process used to test embryos for serious inherited genetic conditions and chromosomal abnormalities before pregnancy. This can be especially important for a parent or parents already diagnosed with a rare disorder, or for those parents who have previously had a child that has been diagnosed with a rare disorder. PGS checks the number of chromosomes in each embryo developed in the laboratory five or six days after fertilisation.

How it works:Embryo biopsy

  • An embryo is created through IVF
  • Five or six cells are removed with a fine glass needle
  • Cells are tested for specific genetic conditions or chromosomal disorders
  • Embryos with normal chromosomes can then be implanted in the mother’s womb, or frozen for later implantation.

In New Zealand, pre-implantation genetic screening is permitted for serious conditions where a child has at least a 1:4 chance of inheriting the condition or chromosomal abnormality.

Public funding and eligibility

Parents need to meet a number of criteria to receive a referral for a publicly funded consultation and treatment with a fertility specialist. Some criteria depend on your District Health Board. You can look up your region through this link on the Fertility Associates website to check the relevant criteria and referral process for your region for accessing a publicly funded consultation and treatment.

Fertility Associates provides free 15 minute confidential phone consultations with a nurse, to discuss your fertility and the options available. You can book a consultation through this link on the Fertility Associates website.

More information about fertility and genetic screening can be found on the Fertility Associates website.

James