Limits of viability

Limits of viability: Counseling the parents

“The anticipated birth of a neonate at the threshold of viability (25 or fewer completed weeks of gestation) presents a variety of complex medical, social, and ethical concerns.” The American Academy of Pediatrics and American College of Obstetricians and Gynecologists recommend that obstetric and neonatal health care providers confer regarding the approach to such a delivery, and then counsel the parents consistently and compassionately as to reasonable expectations for the infant’s outcome and care.

Neonatology counseling in anticipation of extreme preterm birth should include the following information:

A range of the current possible survival rates (preferably institution-specific figures)
An overview of potential medical problems and their treatment and complications
The possibility of long-term disabilities, including mental retardation, cerebral palsy, blindness, deafness, and learning disabilities/need for special education
The possibility that expectations may change after delivery, based on a more accurate assessment of the gestational age and condition of the newborn
Care should be taken not to include interventions of unproven benefit as “doing everything possible” for the neonate.

The neonatologist counseling the expectant mother of an extremely immature infant should document their discussion either in the mother’s written chart or in the mother’s electronic StarChart. Documentation should include:

When the discussion occurred
Who spoke to whom (include all individuals present)
Identifying specifics of the particular case and conversation
The conclusion reached regarding the desires of the family
Need for ongoing evaluation and discussion as the situation evolves
Possible reassessment based upon the condition of the infant.

For more information:

"Management and Outcomes of Very Low Birth Weight" and "Intensive Care for Extreme Prematurity - Moving Beyond Gestational Age" (New England Journal of Medicine 2008)

The NEJM article by Dr Tyson has been published. I do not think it changes much of what we already know but it does add an element of quantification to the improved outcomes associated with being female, singleton, larger, and having received antenatal steroids. The important factor of reason for delivery was not evaluated much to my disappointment. The link below is to the calculator. Which gives a result in percentages- for example for an estimated 600 gram 23 week girl with antenatal stereoids

Survival	40%	51%
Survival Without Profound Neurodevelopmental Impairment	27%	35%
Survival Without Moderate to Severe Neurodevelopmental Impairment	17%	22%
Death	60%	49%
Death or Profound Neurodevelopmental Impairment	73%	65%
Death or Moderate to Severe Neurodevelopmental Impairment	83%	78%

* These estimates are based on standardized assessments of outcomes at 18 to 22 months of infants born at NRN centers between 1998 and 2003; infants were 22 to 25 weeks, between 401 and 1,000 grams at birth. Infants not born at a Network center and Infants with a major congenital anomaly were excluded. The first column of estimates is based on findings for all 4,446 infants in the study. The second column of estimates is based only on the 3,702 infants who received intensive care. The rate of a given outcome had intensive care been attempted for all infants is likely to be intermediate between these two estimates. Sonographic estimates of fetal weight may be used in anticipating birth weight, while assessing the minimum and maximum likely birth weight consistent with the potential error of sonographic estimates.

These data are not intended to be predictive of individual outcomes. Instead, the data provide a range of possible outcomes based on specific characteristics. Researchers conducted their analysis at level III NICUs, specialized facilities offering medical care for newborn infants. The statistics may not apply to infants born at lower level NICU facilities. Please note that these data provide only possible outcomes, and that the estimates apply only at birth. It is also important to note that outcomes change over time and that they differ for a variety of reasons, including NICU features, patient population, obstetric complications and care, and care after discharge home.

If you choose to use these data to determine possible outcomes, please remember that the information provided is not intended to be the sole basis for care decisions, nor is it intended to be a definitive prediction of outcomes if intensive care is provided. It is important for users to keep in mind that every infant is different, and that factors beyond these standardized assessments may influence infant outcomes.

Outcome Calculator: http://www.nichd.nih.gov/about/org/cdbpm/pp/prog_epbo/epbo_case.cfm

The following graphs and statistics may prove useful in counseling the pregnant mother of a fetus at the threshold of viability. A handout is available to provide to parents anticipating the birth of an extremely premature infant to assist them in making informed difficult decisions.

National and international survival data were recently published in Pediatrics, Nov. 2002:

Neonatal Survival/Morbidity by Gestational Age and Birth Weight

Factor Mean Survival Rates (%) Moderate or Severe Disability (%)

EPICure NICHD EPICure NICHD

EGA (wk)

23 11 30 56 ---

24 26 52 53 ---

25 54 76 46 ---

Weight (g)

401-500 11 --- *

501-600 27 --- 29

601-700 63 --- 30

701-800 74 --- 28

*Too few infants to assess

Vanderbilt’s survival and morbidity statistics from 2005 are similar:

EGA Survival Morbidity

22 weeks 0% ---

23 weeks 25% 90%

24 weeks 50-60% 66%

25 weeks 75% 33%

These data are depicted in the following graph:

Problems of prematurity include, of course:

Lung immaturity

PDA

Infection

NEC

Brain injury

Inadequate nutrition and growth

Retinal injury

Recently published NICHD data are summarized below:

Serious Neonatal Morbidities in Premature Infants of <750g Birthweight, 1995-1996

Condition

Respiratory distress syndrome

Oxygen need at 28 days of age

Chronic lung disease at 36 weeks

Necrotizing enterocolitis

Septicemia

Grade III-IV intraventricular hemorrhage

Periventricular leukomalacia

Growth failure (< 10%ile at 36 weeks)

Frequency of Morbidity with Range (%)

78% (54 - 97%)

81% (64 – 92%)

52% (8 – 86%)

14% (9 – 38%)

48% (30 – 64%)

26% (3 – 29%)

7% (2 – 30%)

100% (92 -100%)

Long term problems and handicaps associated with extreme prematurity include:

Bronchopulmonary dysplasia/chronic lung disease:

Mental retardation

Cerebral palsy

Visual-impairment / blindness

Hearing loss / deafness

Learning disabilities / school problems

Behavioral and emotional problems

21 – 36% require home oxygen

10% with IQ < 70; average mean IQ 80

5-10%

30% / 1%

7% / 3%

56%

58%

The report, Critical Care Decisions in Fetal and Neonatal Medicine:Ethical Issues, is available at www.nuffieldbioethics.org

The guidelines at a glance*


Premature birth (wks)	Likely outcome	Recommended action
22-23	Only 1% are likely to survive	Do not give intensive care unless parents request it, then only after full discussion of risks and with the doctor's agreement
23-24	11% are likely to survive, but predicting whether they will live, die, be healthy, or have disabilities later is difficult. The EPICure study shows two thirds had moderate to severe disabilities	Parents, after a thorough discussion with the healthcare team, should have the final say over whether intensive care is given.
24-25	26% are likely to survive	Give intensive care unless the parents and doctors agree there is no hope of survival or the level of suffering outweighs the baby's interest in continuing to live
>25	The baby has a sufficiently high chance of surviving (44% at 25 weeks) and low risk of developing severe disability (two thirds have no or only mild disabilities)	Intensive care should normally be given

*Active ending of life is not allowed no matter how serious the condition. Where a decision has been made to withdraw treatment, palliative care, including pain relief, should be given.

Survival rates are based on Costeloe K, Hennessy E, Gibson AT, Marlow N, Wilkinson AR and the EPICure study group. The EPICure study: outcomes to discharge from hospital for babies born at the threshold of viability. Pediatrics 2000;106:659-71.

It is important to remember, and to emphasize to parents, that the chances of survival at any given gestation may vary 10-fold depending upon that particular infant’s risk factors and clinical condition. Epidemiologic factors including gender, race, and inborn vs. outborn status significantly impact survival, as shown in the graph below. Also, associated medical conditions may worsen odds of survival and prognosis including PPPROM, maternal chorioamnionitis, and abruption.

Discussed at Clinical Faculty Meeting 1/06/03.

References:

AAP/ACOG. Guidelines for Perinatal Care, 5^th ed. “Births at the threshold of viability.” pp. 171-2.

MacDonald H. “Perinatal Care at the Threshold of Viability.” Pediatrics 2002; 110: 1024-1027.

Lemons JA, et al. “Very low birth weight outcomes of the National Institute of Child Health and Human Development Neonatal Research Network, January 1995 through December 1996. Pediatrics 2000; 107(1). http://www.pediatrics.org/cgi/content/full/107/1/e1

Wood NS, et al. Neurologic and developmental disability after extremely preterm birth. EPICure Study Group. N Engl J Med 2000; 343: 378-384.

Hack M, Friedman H, Fanaroff AA. Outcomes of Extremely Low Birth Weight Infants. Pediatrics 1996; 98: 931-937.

Vohn BR, Msall ME. Neuropsychological and functional outcomes of very low birth weight infants. Semin Perinatol 1997; 21: 202-220.