Understanding and Navigating Viability

The concept of viability of a fetus is frequently misrepresented or misinterpreted based on ideological principles. This perpetuates incorrect and unscientific understandings of medical terms and leads to interference in the practice of medicine. As people across the United States continue to navigate the developing post-Dobbs landscape, it’s critical that medical terminology be understood through the lens of science rather than the lens of political application and interpretation. Understanding viability is especially important as policy makers and those who interpret policy draw on the concept of viability in order to inform and create laws. As such, ACOG strongly discourages the inclusion of viability in legislation or regulation.

This document will explain how the term “viability” is used in the context of medical practice during pregnancy and how viability relates to the provision of abortion care and affirm how using terminology inaccurately, including inaccurate use by policy makers, can prevent patients from receiving essential health care grounded in evidence and science. 

“Viability” in Two Contexts

While there is no single formally recognized clinical definition of “viability,” the term is often used in medical practice in two distinct circumstances. In the first, “viability” addresses whether a pregnancy is expected to continue developing normally. In early pregnancy, a normally developing pregnancy would be deemed viable, whereas early pregnancy loss or miscarriage would not. 

In the second, “viability” addresses whether a fetus might survive outside of the uterus. Later in pregnancy, a clinician may use the term “viable” to indicate the chance for survival that a fetus has if delivered before it can fully develop in the uterus. Clinicians most commonly focus on the periviable period, which refers to weeks 20 through 25 and 6 days of a pregnancy. However, according to ACOG and the Society for Maternal–Fetal Medicine’s Obstetric Care Consensus #6, Periviable birth, rates of neonatal survival to discharge at this time range dramatically from 23% to 27% for births at 23 weeks, 42% to 59% for births at 24 weeks, and 67% to 76% for births at 25 weeks of gestation. The consensus also notes that deliveries before 23 weeks have a 5–6% survival rate and that significant morbidity is universal (98–100%) among the rare survivors. 

Fetal viability depends on many complex factors, of which gestational age is only one. While gestational age may be helpful in predicting the possible chance that the fetus would survive at time of delivery, many other factors also influence viability, such as sex, genetics, weight, circumstances around delivery, and availability of a neonatal intensivist health care professional. Even with all available factors considered, it still isn’t possible to definitively predict survival. While some fetuses delivered during the periviable period can survive, they may also experience significant morbidity and impairment. 

In the periviable stage, clinicians consider several factors to help determine a general percentage chance of survivability. The resulting percentage is not a definitive diagnosis but rather an estimate created from data points that reflect a population average. While clinicians cannot predict with certainty the outcome for an individual pregnancy or fetus, they can help patients understand their individual risks and circumstances so that they can make informed decisions for their pregnancy and their individual health.

Clinicians who provide obstetric care are in the best possible position to consider all factors when attempting to predict viability either when establishing a pregnancy diagnosis or assessing later in pregnancy. In early pregnancy care, determining viability is a more straightforward diagnosis that suggests that a pregnancy will not result in a live birth regardless of intention. In the periviable period and afterwards, viability often is not a definitive diagnosis at all; rather, a clinician’s prediction about viability includes information that clinicians can share with patients so that patients and their families can be fully informed when they make shared decisions about their health care. Policy making around viability interferes in the patient–physician relationship. ACOG strongly opposes legislation or regulation of the clinical definition of viability.

Determining Viability and Other Prognoses

There is no definite diagnosis of viability and no test that can definitively determine whether a fetus could survive outside of the uterus, so determining whether a pregnancy is viable beyond the first trimester is often based on clinical judgment. Clinicians will use ultrasound results and pregnancy hormone levels in early pregnancy to determine whether a pregnancy is developing normally and is thus viable. However, a determination of viability at this stage doesn’t mean that the fetus could survive if delivered later in pregnancy. 

While it is impossible to definitively declare viability, there are several situations in which a pregnancy will never be viable, regardless of gestational age. Tubal ectopic pregnancies will never be viable, and the treatment for ectopic pregnancy requires ending the nonviable pregnancy. Early pregnancy loss by definition is a nonviable pregnancy and warrants intervention if desired or indicated.

There are also fetal conditions for which survivability will be poor, regardless of when the pregnancy ends. Those conditions include genetic or isolated structural abnormalities in which essential structures do not develop properly and the fetus may only survive a matter of minutes or days after delivery. In these cases, patients may decide to end their pregnancies through abortion, or to choose to give birth with options for palliative care. If patients choose the latter, the American Academy of Pediatrics has stated that patients and families should also be allowed to choose palliative care or attempted resuscitation in light of the high likelihood of death and significant degree of neurodevelopmental impairment that may result from birth. If patients choose to attempt resuscitation, clinicians should discuss with patients and families whether their goal is optimizing survival or minimizing suffering when formulating a plan of care. In such instances, as in the rest of medicine, these compassionate conversations should take place without political interference. 

Abortion Later in Pregnancy

Abortions later in pregnancy account for less than 1% of all abortion care. There are a number of reasons why patients may seek care during or after periviability: 

  • As a result of a fetal diagnosis received later in pregnancy that may have a profound impact on the pregnancy’s prognosis
  • As a result of a diagnosis related to risks to their own health during pregnancy that did not present until later in pregnancy
  • Not recognizing that they were pregnant until later in the pregnancy, which may delay them in presenting to start care
  • Barriers to obtaining care earlier in pregnancy, including limited financial means, inability to travel, or work or childcare obligations
  • A combination of any of the above 

Viability is just one factor that patients and health care professionals use when considering whether to proceed with or end a pregnancy, and gestational age is only one factor considered when estimating viability. Legislative bans on abortion care often overlook unique patient needs, medical evidence, individual facts in a given case, and the inherent uncertainty of outcomes in favor of defining viability solely by gestational ages. Therefore, ACOG strongly opposes policy makers defining viability or using viability as a basis to limit access to evidence-based care.

While people may have differing views on abortion, those views must not interfere with the relationship between people and their clinicians. People should be able to access the health care they need from the clinicians who understand their patients’ situation and have patient health and well-being in mind. 

Coding for Viability

Medical coding used for billing purposes uses language that may include viability and may be confusing. For example, the code International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) O36.80X0: Pregnancy with inconclusive fetal viability, not applicable or unspecified, is often used in the first trimester when the diagnosis of whether a pregnancy is normally growing cannot be determined. Other diagnosis codes that can be used include:

  • O02.89: Other abnormal products of conception
  • O02.9: Abnormal product of conception, unspecified
  • O00.90: Unspecified ectopic pregnancy without intrauterine pregnancy
  • O00.91: Unspecified ectopic pregnancy with intrauterine pregnancy

ACOG maintains that using ICD-10-CM codes that include the term “viability” should not be used to restrict the care a patient receives. Questions around denials for reimbursement based on the appropriate use of ICD-10-CM codes can be submitted to the ACOG Payment Advocacy & Policy Portal