November 17, 2020

Equity Through Innovation: New Methods of Genetic Screening Lead to Healthier Pregnancies for All

By Shivani Chinnappan, SWHR Programs Coordinator, and
Melissa Laitner, PhD, MPH, SWHR Director of Public Policy and Government Affairs

In 2020, SWHR is bringing attention to the need for advances in diagnostic and screening tests across a variety of diseases and conditions to improve the health of women. In the last blog of this series, we discuss new innovations in health screening technology that are improving health equity during pregnancy.

Certain heritable conditions can create challenges for a healthy pregnancy: They may cause developmental concerns for a newborn or affect an individual’s ability to carry a pregnancy to term.

Pre-pregnancy and prenatal screening can provide parents-to-be with a more comprehensive understanding of risk for passing on a genetic condition to their children. However, these types of screenings have not always been equally accessible or effective for patients. Below, SWHR discusses recent innovations leading to more equitable approaches to screening, and outlines next steps for improving access to pre-pregnancy and prenatal screening.

Expanding Screening Across Ethnicities

Carrier screening is a method of genetic screening that allows people to determine whether they are carriers for certain recessive and X-linked genetic conditions, and whether or not they risk passing that condition to their future children.

For many years, screening programs targeted certain ethnic groups that have the highest risk for passing on specific heritable conditions. However, new methods are capable of detecting carrier status for more than 100 conditions using just one blood or saliva sample, regardless of patient ethnicity.

The goal of this expanded carrier screening (ECS) is to identify the most at-risk couples for serious  genetic conditions within our increasingly diverse population. This is important as determining a person’s racial and ethnic background can be complicated: recent research indicates one in 10 individuals self-report ethnicity that is inconsistent with actual genetic ancestry. This can lead to missed screening opportunities for individuals who may not know they are a member of a high-risk population.

The same study suggests that among seven of 16 typically screened-for conditions, the majority of carriers identified through screening may not be members of the identified high risk groups, indicating that even those who self-identify correctly may benefit from expanded screening. ECS targets all ethnicities, instead of screening only certain groups based on presumed risk, meaning that potential missed carriers are more likely to be captured.

ECS also includes a longer list of targeted conditions. Traditional screening methods are used to identify “common” genetic disorders, but overall occurrence of the broad collection of disorders identified by ECS is much higher than any single incidence of one of the “common” conditions. Therefore, it may particularly help patients at risk for conditions not included on traditional screening panels. Widespread use of ECS during the preconception period may help improve neonatal health outcomes and reduce maternal morbidity through early recognition of risk for a wide array of heritable conditions.

Improving Screening for Diverse Body Types

Certain types of prenatal screening methods can help pregnant people understand whether their fetus may be at risk for select chromosomal conditions. Noninvasive prenatal screening (NIPS) uses a blood sample, taken from the birthing parent, to examine cell-free DNA (cfDNA) from the fetus that is also found in the parent’s bloodstream.

However, using cfDNA to test for certain fetal conditions has shown limited effectiveness in certain subgroups of patients. Specifically, lower proportions of fetal DNA are found in the pregnant parent’s bloodstream as the parent’s weight increases. Although body mass index (BMI) has not been shown to be a reliable indicator of health status, those with a BMI of 35 or above may be much more likely to receive uninformative results when undergoing NIPS.

Given the medical field’s history of leaning into inaccurate biases about obesity, screening methods that are less effective in those with higher BMIs may inadvertently perpetuate harmful stereotypes of heavier individuals as more difficult patients. Moreover, using screening methods rendered less effective by changeable personal characteristics such as weight contributes to weight-based health disparities.

Fortunately, new methods of NIPS now allow patients of any weight to receive more accurate results without the need for more invasive methods of testing with higher potential for harm to the parent or fetus. Technology that amplifies the proportion of fetal cfDNA allows nearly all pregnant individuals to have confidence in their NIPS results.

Improving Access to Care

Ensuring that sociodemographic factors, such as race or ethnicity, and personal attributes, such as weight, do not affect access to care or quality of care is crucial if we hope to eliminate disparities within our health care system. However, there is still more to do to ensure all future parents and pregnant people have access to safe, high-quality pre-pregnancy and prenatal care.

A recent article in Nature about ECS underscores continued challenges within this area, including the possibility of disability-based discrimination and ongoing technical and socio-cultural limitations. There exists a general lack of consensus in the clinical community as to who should be offered ECS, the timing of testing, and how to determine which conditions should be included in screening.

Insurance poses another obstacle to universal applications of prenatal screening, although recent guidance from the American College of Obstetricians and Gynecologists (ACOG) suggests prenatal screening should be offered to all pregnant persons.

NIPS coverage scorecards suggest many national plans only cover screening for patients considered to be high risk, despite the fact that universal application of NIPS has been found to be economically justified and associated with substantial health benefit. ECS also presents challenges for insurers, as they have yet to determine a systematic method of addressing which tests to cover.

Innovative screening and diagnostic technologies can be hugely beneficial for improving preventive care and health outcomes during pregnancy. Using new technologies to address health disparities is a particularly promising way forward. As technology continues to advance, science must take care to ensure research does not perpetuate disparities, and more importantly, seeks to improve health equity.

Read more about ECS and NIPS, or learn about how innovations in screening are improving diagnosis and treatment of serious health care conditions such as cancer, premature birth, and endometriosis.

SWHR’s genetic screening and diagnostic testing blog series is supported by a grant from Myriad Women’s Health. SWHR maintains editorial control and independence over blog content.