Before Pregnancy Begins: Why the Timing of Carrier Screening Matters

In women’s health, we have become more proactive. We counsel patients on folic acid before conception. We optimize management of blood pressure and glucose. We review medications and chronic conditions well before pregnancy begins.

And yet, one conversation still often waits until the first prenatal visit: carrier screening. In some cases, the conversation may not happen at all.

Both the American College of Obstetricians and Gynecologists (ACOG) and the American College of Medical Genetics and Genomics (ACMG) acknowledge that carrier screening is ideally performed before pregnancy. This recommendation has been supported for years, reflecting its established value in clinical practice. What remains inconsistent is how often it is implemented.

If we begin to think about carrier screening as part of routine preventive care, rather than something tied only to pregnancy, we have an opportunity to fundamentally change how and when patients access this information.

Why Carrier Screening Matters for Every Patient

Expanded carrier screening panels that assess dozens to hundreds of recessive and X-linked conditions identify carriers in a substantial proportion of individuals, reflecting the commonality of carrier status across diverse populations.

Most of these individuals are healthy. They have no symptoms. They may have no known family history.

In fact, approximately 80% of infants born with cystic fibrosis are born to families with no prior history of the condition. Additionally, while Tay-Sachs disease is historically associated with Ashkenazi Jewish ancestry, it also occurs in the broader population. The carrier rate is estimated at 1 in 300 in the general U.S. population. As our patient populations become increasingly diverse and globally interconnected, ancestry-based screening alone is no longer sufficient.

Being a carrier is common and crosses demographic and ethnic boundaries. Early screening helps identify potential risks thoughtfully and fairly before options become limited during the pregnancy.

Why Timing Changes the Conversation

Carrier screening during pregnancy is still clinically valuable. But the experience — for both patients and providers — is fundamentally different when it happens before conception.

When screening occurs after pregnancy begins, discussions about partner testing, confirmatory evaluation, and reproductive options must occur within a limited timeframe. For autosomal recessive conditions, partner testing is crucial for accurately assessing risk. Coordinating partner testing and interpreting the results may require additional time, during a period when emotional stress is already high, and options may feel limited.

Preconception screening changes that dynamic in important ways.

Screening before a patient becomes pregnant allows more time to complete partner testing, consider reproductive options such as IVF with preimplantation genetic testing (PGT), explore donor gametes, or plan for standard/traditional conception and pursue diagnostic testing.

It also gives patients space to absorb information without the immediate pressure of an ongoing pregnancy.

In that setting, the conversation shifts from reactive to proactive. Instead of responding to new risks within a pregnancy, clinicians and patients can approach reproductive planning with clarity, preparation, and choice.

Preconception timing does not change the science of carrier screening — but it meaningfully changes the experience.

The Gap Between Interest and Implementation

Although preconception carrier screening is preferred over screening during pregnancy, population-wide preconception screening is not routinely conducted in the United States due to multiple barriers in care delivery.

In practice, the gap is in how care is delivered. Many patients are unaware that they can schedule a dedicated preconception visit. When these conversations do occur, they are often incorporated into already time-constrained visits, such as annual physical exams, where carrier screening may be reduced to a brief mention rather than a meaningful educational discussion.

Studies show that when expanded carrier screening is offered during the preconception period, acceptance rates range from approximately 8% to 34%, compared to 32% to 76% when screening is provided during pregnancy. This highlights how inconsistently preconception screening is incorporated in preventive women’s health education and, therefore, rarely implemented.

For OB/GYNs and primary care physicians, the barriers are often related to workflow. In primary care settings in particular, pathways for ordering tests, coordinating partner testing, interpreting and delivering patient results and providing appropriate follow-up and genetic counseling may be less established.

Many patients are unaware of carrier screening and do not inquire about it, partly due to concerns about cost and coverage, which can further hinder its uptake. However, for many, both preconception and pregnancy carrier screening is covered. Additionally, various financial assistance programs exist that patients may not be aware of.

Interpretation Matters as Much as Detection

Carrier screening belongs alongside the preventive conversations we already prioritize in preconception care. We already prioritize in preconception care so it can most meaningfully guide decisions.

But for carrier screening to truly support patients, the test itself is only part of the equation. Clear reporting, accessible genetic counseling, and coordinated partner testing pathways are essential. Even when a variant is identified, the work is not complete. Some findings are straightforward, while others require careful interpretation.

Meaningful screening depends on consistent classification standards and up-to-date genotype-phenotype data. It also requires a clear plan for genetic counseling and follow-up to ensure patients and providers understand the next steps.

Speed is important, but accuracy and context matter more. Artificial intelligence can help prioritize findings, but expert clinical review remains critical to translating results into care decisions. A genetic test is only as meaningful as the interpretation that accompanies it.

When carrier screening is integrated into a coordinated testing pathway — alongside prenatal screening and diagnostic follow-up when appropriate — the experience becomes more seamless for both patients and providers.

Integrated genetic testing ecosystems, such as those offered by Labcorp, including Labcorp Carrier Screening, MaterniT® cfDNA (NIPT), and Reveal® SNP Microarray, along with customizable genetic counseling services, help maintain continuity across the reproductive journey.

Awareness for Providers and Patients Opportunity

The benefit of supporting preconception carrier screening is clear. The question is no longer whether to offer it, but how consistently we integrate it into the standard of care. To do so, we must consistently educate and raise awareness among both providers and patients.

Looking ahead, there is an opportunity to rethink how and when carrier screening is offered. Rather than tying it exclusively to pregnancy, carrier screening could become part of routine preventive care — introduced at a defined point in early adulthood. Because it is performed just once in a lifetime, offering it earlier could help close access gaps and ensure more patients have this information before they need it and when they can consider multiple reproductive options if needed.

If we are committed to preventive women’s health, then providing carrier screening before pregnancy is not an expansion of care — it is an enhancement of it.

Explore carrier screening options and resources to support informed patient care.