Genetic carrier screening

It is the first antenatal visit. A 28-year-old woman, eight weeks pregnant, asks whether she should be "tested for genetic things." The question is deceptively simple. Done well, carrier screening gives a couple knowledge and choice; done badly — late, unexplained, or with a result dumped without counselling — it generates anxiety and narrows options that did not need to narrow. The fellowship answer turns on three things: who to screen, when, and what you do with a positive result.^[1][3]

Overview and definition

Reproductive carrier screening is the testing of healthy individuals to find out whether they carry a gene change that, combined with the same change in a partner, could cause a serious genetic condition in a child. It is parental genotype testing — distinct from prenatal screening (fetal aneuploidy by cfDNA or combined test) and from newborn screening (the heel-prick).^[1]

The reason it exists is the single most examinable fact in the topic: most couples who have an affected child have no family history and did not know they were carriers. Inherited conditions are individually rare but collectively common — about 1 in 400 people are affected by one — so screening everyone, not just those with a family history, is what catches the risk.^[1]

References10ShowHide

1. [1]Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) Genetic Carrier Screening (C-Obs 63), Interim Update July 2024 RANZCOG Statement, 2024.Source
2. [2]Kirk EP, Delatycki MB, Archibald AD, et al. Nationwide, Couple-Based Genetic Carrier Screening N Engl J Med, 2024.PMID 39565987
3. [3]Archibald AD, McClaren BJ, Caruana J, et al. The Australian Reproductive Genetic Carrier Screening Project (Mackenzie's Mission): Design and Implementation J Pers Med, 2022.PMID 36579509
4. [4]Westemeyer M, Saucier J, Wallace J, et al. Clinical experience with carrier screening in a general population: support for a comprehensive pan-ethnic approach Genet Med, 2020.PMID 32366966
5. [5]Capalbo A, Fabiani M, Caroselli S, et al. Clinical validity and utility of preconception expanded carrier screening for the management of reproductive genetic risk in IVF and general population Hum Reprod, 2021.PMID 34021342
6. [6]Aul RB, Canales KE, De Bie I, et al. Reproductive carrier screening for genetic disorders: position statement of the Canadian College of Medical Geneticists J Med Genet, 2025.PMID 40850740
7. [7]Grody WW, Thompson BH, Gregg AR, et al. ACMG position statement on prenatal/preconception expanded carrier screening Genet Med, 2013.PMID 23619275
8. [8]Ontario Health (Quality) Carrier Screening Programs for Cystic Fibrosis, Fragile X Syndrome, Hemoglobinopathies and Thalassemia, and Spinal Muscular Atrophy: A Health Technology Assessment Ont Health Technol Assess Ser, 2023.PMID 37637488
9. [9]Morbey EJ, Day FR, Wright DJ, et al. Large-scale analysis of FMR1 CGG repeat length and risk of premature ovarian insufficiency in over 92 000 women Hum Reprod, 2026.PMID 42001465
10. [10]Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) Pre-pregnancy counselling (C-Obs 3a), Version 13.1 RANZCOG Clinical Guideline, 2024.Source