Prenatal screening tests: are they accurate?

Written by: Dr Melita Irving
Published: | Updated: 20/09/2023
Edited by: Emma McLeod

Prenatal screening, unlike genetic testing, is done without any previous indication of a genetic disorder. Dr Melita Irving is a leading London-based clinical geneticist with extensive experience in diagnosing and managing a wide range of genetic conditions. In this article, she provides you with insight into prenatal screening.

Digital image of DNA

What are prenatal genetic screening tests?

Genetic testing is available if your baby has a risk of inheriting a condition running in your family or has physical anomalies on ultrasound scan.


Genetic screening, on the other hand, is done ‘blind’ and is designed to give reassurance to worried would-be parents with no prior concerns. This is usually in the form of chromosome analysis. DNA extracted from a CVS (chorionic villous sample) or amniocentesis is needed and later on, it is found in the mother’s blood (non-invasive prenatal testing – NIPT).


How accurate are prenatal screening tests?

Prenatal testing for a specific genetic change is extremely accurate, but prenatal screening may be less so and cannot be completely reassuring – the tests are only as good as the question they are being asked.


What should I consider when deciding whether to have prenatal genetic testing?

It should be based on your individual situation and because it can be difficult to know whether you need genetic testing or not, a clinical geneticist can help you work out if testing would be helpful.


Can I do anything before I get pregnant?

Carrier testing for you and your partner is available. This test determines yours and your partner’s risk of being a carrier for specific genetic disorders.


Where could I learn more?

Melita Irving is the author of Haynes Human DNA Manual – Understanding your genetic code

Haynes Publishing 28 Oct 2019

ISBN-10: 1785215949


Melita Irving is a consultant in clinical genetics and available to help you and your partner with a screening test and, if needed, the management of genetic conditions. Click here to learn more and to get in touch.

By Dr Melita Irving
Clinical genetics

Dr Melita Irving is an expert London-based consultant and honorary reader in clinical genetics.  After initially training in paediatrics, she now specialises in genetic conditions, and has extensive experience in diagnosing and managing a wide range of genetic conditions. Her specialist interests include chromosomal disorders, rare genetic symptoms, and conditions with an underlying genetic cause.

Her sub-specialism is rare diseases of the skeleton. She has established multidisciplinary paediatric clinics in skeletal dysplasia offering a close monitoring and management service, and is an active researcher, working to develop and improve the diagnosis of severe skeletal conditions. She currently acts as the chief investigator for clinical trials in children with skeletal dysplasia, developing the diagnosis of genetic conditions and improving the accurate diagnosis of severe skeletal conditions. Her work is featured in many peer-reviewed publications and she has published extensively on various aspects of clinical genetics.

Dr Irving was a winner of the Genetic Healthcare Provider (GHP) Private Healthcare Awards 2019. In that same year, she published a book, The Human DNA Manual, offering insight into the origins, evolution and uses of genetic science. 

View Profile

Overall assessment of their patients

  • Related procedures
  • Breast cancer
    Hypertension (high blood pressure)
    Degenerative nerve disease
    Skeletal dysplasia
    Genetic testing
    Down’s syndrome
    Huntington's disease
    This website uses our own and third-party Cookies to compile information with the aim of improving our services, to show you advertising related to your preferences as well analysing your browsing habits. You can change your settings HERE.