Genetic carrier screening before pregnancy: What to know

Article produced in association with London Pregnancy Clinic and Jeen Health

For the majority of couples planning a pregnancy, genetic testing is not something they think about until a problem arises.

Pre-conception genetic carrier screening challenges this approach by identifying risk before pregnancy begins.

As panel sizes have grown and at-home testing options have become widely available, carrier screening is transitioning from a niche clinical referral into a mainstream component of reproductive planning.

What Carrier Screening Tests For

Being a carrier of a genetic condition means carrying one copy of a variant in a gene associated with that condition, without being affected by it.

In most cases, carriers are entirely unaware of their status.

The clinical significance of carrier status emerges when both members of a couple carry a variant in the same gene: in this scenario, each pregnancy carries a one in four chance of resulting in a child who inherits two copies of the variant and is affected by the condition.

The conditions most frequently included in expanded carrier screening panels include cystic fibrosis, spinal muscular atrophy (SMA), fragile X syndrome, sickle cell disease, and a range of metabolic and enzyme deficiency disorders.

The Beacon 787 carrier test, offered by Jeen Health, screens for 787 conditions from a single sample, making it one of the most comprehensive panels currently available to UK families.

Who Is Most Likely to Benefit

Any couple planning a pregnancy can consider carrier screening. It is particularly relevant for:

• Couples with a family history of a known inherited condition
• Those from populations with higher carrier frequencies for specific conditions, including Ashkenazi Jewish, South Asian and African communities
• Couples pursuing fertility treatment, where genetic information informs treatment planning
• Those who wish to have the most complete picture of their reproductive health before conception

Importantly, being a carrier of a condition does not mean a child will be affected. It means there is a defined statistical risk that can be quantified, discussed and planned for with appropriate clinical support.

How the Test Is Performed

Carrier screening is typically carried out on a blood or saliva sample.

For at-home options such as the testing offered by Jeen Health, a cheek swab collection kit is dispatched to the patient, the sample is returned by post, and results are delivered digitally within a defined turnaround period.

In-clinic carrier testing may use a blood draw and provides the advantage of immediate access to a clinical consultation at the point of result delivery.

London Pregnancy Clinic offers genetics counselling through its partnership with Jeen Health, allowing couples to receive and contextualise carrier test results with expert support.

Genetic counselling before and after testing is recommended by Genomics England as a standard component of any genomic testing pathway.

What Happens If Both Partners Are Carriers

If both partners are identified as carriers for the same autosomal recessive condition, they are typically offered further counselling to discuss their options.

These may include proceeding naturally with an awareness of the risk, using prenatal diagnosis (CVS or amniocentesis) during pregnancy to test the fetus, or pursuing preimplantation genetic testing (PGT) in the context of IVF, which allows unaffected embryos to be selected before transfer.

The purpose of identifying carrier status before pregnancy is to give couples time to consider these options without the added pressure of an ongoing pregnancy.

Knowledge of carrier status does not remove reproductive choices; it expands the information available when making them.

The Role of Pre-Conception Services

Carrier screening sits within a broader category of pre-conception care that includes fertility assessments, general health optimisation and, where relevant, management of existing conditions before pregnancy begins.

London Pregnancy Clinic offers pre-conception services encompassing fertility investigations, genetics counselling and carrier testing as part of an integrated 0th trimester approach, allowing couples to address genetic and clinical risk factors before their pregnancy starts rather than after.

Disclaimer: This article is produced for informational purposes only and does not constitute medical advice, diagnosis or treatment.

Clinical guidance referenced reflects published NHS, NICE and RCOG standards as at March 2026. Individual circumstances vary; readers are advised to consult a qualified healthcare professional before acting on any information in this article.

This piece was produced in association with London Pregnancy Clinic and Jeen Health, which provided background clinical information for editorial purposes.

Hyperlinks to external sources are included for reference only and do not represent an endorsement of any product, service or organisation.