Perinatal Care at the Threshold of Viability

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974 PEDIATRICS Vol. 96 No. 5 November 1995

Perinatal

Care

at the

Threshold

of

Viability

American Academy of Pediatrics

Committee on Fetus and Newborn

American College of Obstetricians and Gynecologists

Committee on Obstetric Practice

SUBJECT REVIEW

The survival rate for infants born prematurely has

changed over the last two decades and is likely to

change in the future. Currently, the birth of an infant

at or before 25 weeks of gestation or weighing less

than 750 g presents a variety of complex medical,

social, and ethical decisions. Although the

preva-lence of such births is low, the impact on the infants,

their families, the health care system, and society is

profound.

The survival of infants born from 23 to 25 weeks of

gestation increases with each additional week of

ges-tation. However, the overall neonatal survival rate

for infants born during this early gestational period

remains less than 40%.1.2 Of those who survive, about

40% have moderate or serious disabilities, and many

have neurobehavioral dysfunction and poor school

performance.3’4 Many require prolonged intensive

care and long-term care.2 The commitment for all

aspects of care may be extensive, multidisciplinary,

lifelong, and costly. Because the families bear the

emotional and financial consequences of the birth of

an extremely low-birth-weight infant, it is essential

to inform the prospective parents regarding the

ex-pectations for infant outcome and the risks and

ben-efits of various approaches to care.

Counseling Regarding Potential Fetal Outcomes

Most parents are unfamiliar with the complexities

of care required for an extremely premature infant,

both in the intensive care unit and after discharge

from the hospital. Therefore, it is often necessary to

provide the information in small segments at

fre-quent intervals to allow the parents to comprehend

the messages. The family can benefit from a clear

explanation of the various supportive procedures

that will likely be necessary in the infant’s first days

of life. Family members should also be provided

with an overview of the potential complications of

prolonged intensive care. Finally, they should be

informed of the range of survival rates and of the

rates of long-term disabilities that can be expected. In

compiling such information, practitioners should

The recommendations in this statement do not indicate an exclusive course of treatment or procedure to be followed. Variations, taking into account individual circumstances, may be appropriate.

Acad-emy of Pediatrics and the American College of Obstetricians and

Gynecol-ogists.

consider data reported in the current literature as

well as outcomes based on local experience; they

should allow for some error in the best estimate of

gestational age and fetal weight.

Neonatal survival rates experienced over the last

decade in different neonatal units are provided in

Table 1. These rates do not represent ultimate

sur-vival rates, as deaths may occur in the postneonatal

period. The prevalence of a number of morbidities

common to these extremely premature infants is

shown in Table 2.

It is difficult to counsel parents regarding

long-term

disabilities because outcomes are only now

be-ing reported for neonates born since the use of

sur-factant became common and who have survived to

school age. Recent experience suggests that almost

half of the surviving children who weigh less than

750 g at birth experience moderate or severe

disabil-ity, including blindness and cerebral palsy, and

re-quire special education. Many infants have more

than one disability. Families should be counseled

that, despite the high rate of overall disability, many

of these children are educable and can function

within their family unit.

The estimation of gestational age before premature

delivery forms the main basis for subsequent

deci-sion-making. Clinical assessment to determine

ges-tational age is usually appropriate for the woman

with regular menstrual cycles and a known last

men-strual period that was confirmed by an early

exam-ination. Fetal measurements derived through the use

of ultrasonography at the time of anticipated

deliv-ery

should not be used to alter estimated gestational

age unless there is a discrepancy of 2 weeks or more

between the age derived by menstrual dating and the

age derived sonographically or the woman is

uncer-tam

about the date of her last menstrual period.

Ultrasonography may provide useful information

re-garding the presence or absence of fetal

malforma-tions that may alter the prognosis. The accuracy of

sonographic measurements and the ability to

ascer-tam

malformations, however, may be reduced in the

presence of oligohydramnios, such as occurs with

ruptured membranes.

Even

in

ideal circumstances, the 95% confidence

limits for a formula-based estimate of fetal weight

are

±15% to 20%. Thus, an infant estimated to weigh

600 g may have an actual birth weight of less than

500 g or more than 700 g. Even relatively small

discrepancies of I or 2 weeks in gestational age or

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AMERICAN ACADEMY OF PEDIATRICS 975

TABLE 1. Neonatal Survival by Gestational Age and Birth Weight

Factor Mean (%) Survival Rates

(Range) Reported for*

1987-1988 1989-1990

Age (wk)

23 23(0-33) 15(0-29)

24 34 (10-57) 54 (27-100)

25 54 (30-72) 59 (47-74)

Weight (g)

501-600 21 (0-44) 20 (0-33)

601-700 33 (9-50) 41 (25-56)

701-800 53 (31-73) 65 (38-83)

*Rates were reported by the National Institute of Child Health

and Human Development neonatal centers.

Data from Hack M, Horbar JD, Malloy MH, Tyson JE, Wright E,

Wright L. Very-low-birth-weight outcomes of the National

Insti-tute of Child Health and Human Development Neonatal Network.

Pediatrics. 1991;87:587-597 and Hack M, Wright LL, Shankaran 5,

et al. Very-low-birth-weight outcomes of the National Institute of

Child Health and Human Development Neonatal Network,

November 1989 to October 1990. Am JObstet Gynecol. 1995:172:

457-464

100 to 200 g in birth weight may have major

impli-cations for survival and long-term morbidity. This

underscores the importance of counseling about

range of possible outcomes. Furthermore, multiple

gestation increases the difficulty of accurate

gesta-tional age assessment, and the prognosis for one

infant ultimately may differ from that of the other(s). Ideally, the obstetric and neonatal physicians,

pri-mary care physicians, and neonatal nurses should

confer before recommendations are made to the

par-ents. The range of possible outcomes and

manage-ment options can then be outlined for the patient and

her family. If maternal transport may be needed, the

obstetrician should be knowledgeable about the

available regional resources and be prepared to

pro-vide basic information to the parents if the specific

clinical circumstances warrant. More detailed

coun-seling can then be accomplished at the receiving unit.

Additional medical opinions and input from other

important sources such as clergy, social workers, and

the institution’s bioethics committee may be offered

to the parents. Counseling should be sensitive to

cultural and ethnic diversity, and a skilled translator

should be available for parents whose primary

lan-guage differs from the language of the care

provid-ers. It should be emphasized that the prognosis for

the newborn may change after birth since a more

accurate assessment of the newborn’s gestational age

and condition may be made at that time.

Counseling Regarding the Risks and Benefits of Management Options

Obstetric Management

Decisions regarding obstetric management must

be made by the parents and their physicians if the

neonate’s prognosis is uncertain; the decisions must

be documented in the obstetric records. Some

deci-sions, such as the choice of cesarean birth, can result

in increased risk of morbidity to the woman.

Few studies have been done to evaluate the

influ-ence of obstetric management on the outcome of

TABLE 2. Serious Morbidities in Infants With Birth Weight

<750 g Experienced by the NICHD Neonatal Centers, 1989_1990*

Condition Frequency, % (Range)

Respiratory distress syndrome 86 (80-100)

Ventilator support at 28 dayst 72 (23-100)

Chronic lung diseases 35 (8-82)

Necrotizing enterocolitis 9 (2-19)

Septicemia 34(13-50)

Grade III intraventricular hemorrhage 13 (5-20)

Grade IV intraventricular hemorrhage 17(0-24)

Seizures 10 (2-14)

Periventricular leukomalacia 11 (7-20)

*NICHD indicates the National Insitute of Child Health and

Human Development.

t Data are for infants alive at 28 days. ::Data are for survivors.

Data from Hack M, Wright LL, Shankaran 5, et a!.

Very-low-birth-weight outcomes of the National Institute of Child Health and

Human Development Neonatal Network, November 1989 to

Oc-tober 1990. Am JObstet Gynecol. 1995:172:457-464

infants at the threshold of viability. Furthermore, literature on this subject is largely retrospective and

often lacks sufficient data regarding potential

con-founding variables. Despite these limitations, study

results have consistently failed to document benefits

of cesarean delivery for extremely premature

in-fants.61#{176} It has even been difficult to document

im-proved outcome with cesarean birth for infants in the

breech position who are extremely premature.7’8

Fur-thermore, injuries to the infant can occur during a

difficult cesarean birth.

Physicians should avoid characterizing

manage-ments of uncertain benefit as “doing everything

pos-sible.” Rather, they should hold discussions with the

family regarding available data and provide an

ex-planation of the risks incurred by management

op-tions, including route of delivery. In the case of

ce-sarean delivery, risks to the woman include not only

those incurred during the perioperative period but

also long-term implications for childbearing since a

vertical uterine incision is often employed. A vertical uterine incision at these gestational ages may extend

into the upper segment and would preclude the

op-tion of vaginal birth in future pregnancy. Counseling

regarding management decisions such as whether to

effect maternal transport should include a discussion

of the potential disadvantages of separating the

mother from supportive family members and

famil-iar caregivers when benefit for the mother or baby is

uncertain.

Parents should be encouraged to actively

partici-pate in discussion regarding maternal transport and

other management decisions. Counseling about

management options and potential outcome allows

the family to more easily choose a course of action that is both medically appropriate and consistent with their own personal values and goals. Whenever possible, a nondirective approach needs to be used;

in some circumstances, however, directive

counsel-ing may be appropriate.11 Counseling may result in the family choosing a noninterventive approach to delivery and management. Because the benefits of different types of obstetric management have not been delineated, families should be supported in such decisions.

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976 PERINATAL CARE AT THE THRESHOLD OF VIABILITY Neonatal Management

Ethical decisions regarding the extent of

resuscita-tive efforts and subsequent support of the neonate

are comp1ex.124 Parents should understand that

de-cisions about neonatal management made before

de-livery may be altered depending on the condition of

the neonate at birth, the postnatal gestational age

assessment, and the infant’s response to resuscitative

and stabilization measures. Recommendations

re-garding the extent of continuing support depend on

frequent reevaluations of the infant’s condition and

prognosis.

When a decision is made not to resuscitate the

infant or to discontinue resuscitation, the family

should be treated with dignity and compassion. This

should include the acknowledgment of the birth of

the infant. Humane and compassionate care must be

provided to the infant, including careful handling,

maintaining a neutral thermal environment, and

gentle monitoring of vital signs.

When medical support is discontinued or death is

inevitable, time should be allowed for the parents

and other family members to hold, touch, and

inter-act with the infant if they desire to do so, both before

and after the infant has died. Naming the infant and

obtaining a photograph may be important to the

parents, and a crib card and name band should be

provided. Birth weight and other measurements

should to be provided to the family as well. Clergy

and other family and friends should be allowed

ac-cess to the infant in a setting that maintains the

dignity of both the family and infant.

Support should be provided to the family by

phy-sicians, nurses, and other staff beyond the time of the

infant’s death. Perinatal loss support groups,

inter-mittent contact by phone, and a later conference with

the family to review the medical events surrounding

the infant’s death and to evaluate the grieving

re-sponse of the parents may be considered.

Summary

The survival rate for infants at the threshold of

viability has been improving. However, there are

insufficient data regarding the cost(s) of initial and

ongoing care of these infants and the long-term

out-come of survivors. Furthermore, there has been little

study of the impact of obstetric management on the

survival rates of extremely low birth weight infants

and on long-term morbidities. Continued research

on these issues is imperative, and physicians need to

remain informed of changing statistics.

AMERICAN ACADEMY OF PEDIATRICS COMMI’ITEE ON FETUS AND NEWBORN, 1994 TO 1995

William Oh, MD, Chairperson Lillian R. Blackmon, MD Marilyn Escobedo, MD

Avroy A. Fanaroff, MD

Stephen A. Fernbach, MD

Barry V. Kirkpatrick, MD

Irwin J. Light, MD Lu-Ann Papile, MD Craig T. Shoemaker, MD

LIAISON REPRESENTATIVES

Garris Keels Conner, RN, DSN, American Nurses Association, Association of Women’s Health, Obstetric, & Neonatal Nurses, National

Association of Neonatal Nurses

James N. Martin, Jr. MD, American College of Obstetricians & Gynecologists

Douglas D. McMillan, MD, Canadian Paediatric Society

Diane Rowley, MD, MPH, Centers for Disease Control & Prevention

Linda L. Wright, MD, National Institute of Child Health & Human Development

AAP SECTION LIAISON

Thomas M. Krummel, MD, Section on Surgery

AMERICAN COLLEGE OF OBSTETRICIANS AND

GYNECOLOGISTS COMMI-I-FEE ON OBSTETRIC PRACTICE,

1994 TO 1995

Michael T. Mennuti, MD, Chairperson Vivian M. Dickerson, MD

Larry C. Gilstrap III, MD

Gay P. Hall, CNM

Peter S. Heyl, MD Iffath A. Hoskins, MD James N. Martin, Jr. MD Sharon T. Phelan, MD

LIAISON REPRESENTATIVES

David H. Chestnut, MD, American Society of Anesthesiologists

William Oh, MD, American Academy of Pediatrics

REFERENCES

1. Hack M, Horbar JD, Malloy MH, Tyson JE, Wright E, Wright L. Very low birth weight outcomes of the National Institute of Child Health and

Human Development Neonatal Network. Pediatrics. 1991 ;87:587-597 2. Hack M, Wright LL, Shankaran 5, et al. Very low birth weight outcomes

of the National Institute of Child Health and Human Development Neonatal Network November 1989-October 1990. Ani JObstet Gtnt’co/. 1995;1 72:457-464

3. Ehrenhaft PM, Wagner JL, Herdman RC. Changing prognosis for very low birth weight infants. Ol’stet Ginecol. 1989;74:528-535

4. Hack M, Taylor H, Klein N, et al. School-age outcomes in children with birth weights under 750 g. N Engi JMed. 1994;331:753-759

5. Hadlock FP, Harrist RB, Sharman RS, Deter FL, Park 5K. Estimation of

fetal weight with the use of head, body, and femur measurements-a

prospective study. Am JObstet Gtn:’co!. 1985;151 :333-337

6. Hack M, Fanaroff AA. Outcomes of extremely-low-birth-weight infants between 1982 and 1988. N Eng! IMed. 1989;321 :1642-1647

7. Malloy MH, Rhoads CC, Schramm W, Land C. Increasing cesarean section rates in very low-birth weight infants. Effect on outcome. JAMA. 1 989;262:1475-1478

8. Malloy MH, Onstad L, Wright E. The effect of cesarean delivery on birth

outcome in very low birth weight infants. National Institute of Child

Health and Human Development Neonatal Research Network. ObstL’t Gynecol. 199177:498-503

9. Worthington D, Davis LE, Grausz JP, St)bocinski K. Factors influencing survival and morbidity with very low birth weight delivery. Obstet Gynecol. 1983;62:550-555

10. Kitchen W, Ford GW, Doyle LW, et aI. Cesarean section or vaginal delivery at 24 to 28 weeks’ gestation: comparison of survival and neonatal and two-year morbidity. Obstet Gipiecol. 1985;66:149 -157

11. American College of Obstetricians and Gynecologists. Ethical decision making in obstetrics and gynecology. ACOG Technical Bull. November 1989;136

12. Rhoden NK. Treating baby Doe: the ethics of uncertainty. Hastings Cent Rep. 1986;16:34-42

13. Lantos JD, Meadow W, Miles SH, et al. Providing and forgoing resus-citative therapy for babies of very low birth weight. JC/in Etlncs.

1992;3:283-287

14. Allen MC, Donohue PK, Dusman AE. The limit of viability-neonatal outcome of infants born at 22 to 25 weeks’ gestation. N Eng! / Mcd. 1993;329:1 597-1601

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1995;96;974

Pediatrics

Obstetricians and Gynecologists and Committee on Obstetric Practice

American Academy of Pediatrics, Committee on Fetus and Newborn, American College of