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WHY CAN'T WE LOVE THEM BOTH
by Dr. and Mrs. J.C. Willke
CHAPTER 13
VIABILITY
What is viability?
It is that stage of fetal development when the baby is
"potentially able to live outside the mother’s womb [that is, can survive],
albeit with artificial help." Roe vs. Wade, U.S. Supreme Court, 1973, p. 45
Can you use viability as a measure of when the baby is human and
therefore has the right to live?
No! To do so is completely illogical. 50 years ago viability was at
30 weeks. 25 years ago it had dropped to 25 weeks. Today we have a survivor at 20 weeks
and several at 21 weeks.
But the babies haven’t changed. Mothers are making the same
kind of babies they always did. But they are surviving earlier.
Why?
Because of a vast increase in the sophistication of the external
life support systems around the baby. Because of neonatal intensive care units. Because of
greater knowledge and skill of the doctors and nurses.
So what is viability?
It is a measure of the sophistication of the external life support
systems around the baby. It is not a measure of his humanness or of his right to live.
But where did this idea
come from?
From ancient times. Until the 19th century, it was assumed that the
baby was not alive in the first half of pregnancy. It was also "known" that when
the mother "felt life," when "the babe doth stir," that at that time
the baby "came alive." Two examples show this: Abortion was always a sin in the
Christian Church. A penitent confessing this sin was given a penance to perform. The
penance for the sin of a late abortion was always more severe than one for an early
abortion. Why? Because in the late abortion she had killed a baby who was alive. English
Common Law succeeded ecclesiastic law and followed the same pattern. Abortion in the first
half of pregnancy was a minor crime, a misdemeanor. Abortion after she felt life, after
"quickening," was a felony, a serious crime.
Has that law changed?
Yes. In the early 1900s it was discovered that the baby’s life
began at conception, not at quickening (Karl Ernst Van Boar, 1827). Accordingly, in 1869
the British changed their law, dropped the felony punishment back to conception, and the
two-tier punishment policy was eliminated.
But the old idea still lives on?
Amazingly, yes. Any lawmaker today who supports protecting
babies’ lives only after viability is still living in the middle ages, in
prescientific times.
How do you measure age of survival?
The age of a premature baby at birth is measured by age from first
day of last menstrual period (LMP). Weight is also a measure when the dates are uncertain,
a 20-to 22-week-old baby has an average weight of 500-600 gm (1 lb., 2 oz. to 1 lb., 5
oz.) with "normals" varying from 400 to 700 gm (14 oz. to 1 lb., 9 oz.). There
are also other maturation factors that are used, such as various measurements made on
ultrasound examination.
The age and weight don’t always track together?
There is a variance, just as with children and adults, but a much
narrower one. Dr. L. Lubchenco, University of Colorado, has been the recognized authority
in preparing most of the charts used. Babies can be small for stated age or
"runts," if malnourished. They can also be large for stated age, but still fall
within the 90 percentile range on the charts.
Will the
survival age ever drop under 20 weeks?
It seems that we have probably reached the youngest
age at which the baby’s lungs are well enough developed to exchange oxygen. One happy
advance has been the use of surfactant in their lungs. This has meant babies under 1500 gm
at birth are 30% less likely to die. Effect of
Surfactant . . . in newborn infants weighing 500-1500 gm, Schwartz et al., N. Eng. J.
Med., 1994; 330 (21): 1476-80 Decreasing Mortality with Surfactant . . . J.Horbar et
al., Pediatrics, Vol.92, No.2, Aug ’93, Pg. 191
A further advance may be using oxygen saturated
liquid instead of air. J.Greenspan et al., Liquid
Ventilation of Preterm Baby, Lancet, Nov 4, ’89, No. 8671,1095 C. Leach,
Partial Liquid Ventilation, N. Eng. J. Med., Sept. 12, ’96
Beyond this it is probably only a question of time and technology.
Some day there will be artificial placentas, and then who knows how early a preemie will
be able to survive?
How young can a
premature baby survive?
It depends first upon the existence of a high-tech neonatal
intensive care nursery. Almost all medical centers in the developed world have these. The
other factor is the baby. Some top notch medical centers just haven’t yet been
blessed with the birth of a child so well developed at an unusually young age that he (or
she) can survive at, say, 20 to 22 weeks.
For instance?
One example is Baby Kenya King pictured
below.
Baby Kenya King born in Plantation, Florida, 21
weeks (4 1/2 months) from the first day of her mother’s last menstrual period;
weighing 510 gm (18 oz) she was 10.5 inches (26.5 cm). She dropped to 370 gm (13 oz). She
is shown at 2270 gm (5 lbs.) with her mother. (Miami Herald, Pam Smith photo)
But a major center such as Johns Hopkins reported the following
survivors:
- at 22 weeks = none
- at 23 weeks = 15%
- at 24 weeks = 56%
- at 25 weeks = 79%
The Limit of Viability, M. Allen et al., N. Eng. J. Med. 11/25/93:
Vol. 329, No.22, pg. 1597
Aren’t
a lot of preemies retarded later?
Many assume this, and there was a problem with those saved 20 years
ago, but "Preterm infants of less than 1,000 gm (2 lbs.,2 oz.) do not appear to have
significantly higher incidence of severe developmental abnormalities in the first 18
months of life than do 1,000 to 1,750 gm babies."
In a study of 68 babies weighing 500-750 gms at
Stanford University, the overall survival rate was 35%. Of these very tiny infants, 9% had
severe handicaps, 36% remedial problems, and the rest were normal. Limiting Treatment for Preme, low wt. Infants, E.W.Young et al., Am. J. Dis.
Ch, Vol. 144, May ’90, Pg 549
How early can preemies
survive?
In your author’s files are 6 cases of 23 week (after LMP)
survivors. Their weights ranged from 16 oz. (540 gm) to 24 oz. (810 gm). We have 11 cases
of survivors at 22 weeks (after LMP). These weights varied from 12 oz. (339 gm) to 22 oz.
(663 gm).
We have 2 cases at 21 weeks (after LMP), including baby Kenya King
above.
And 2 cases at 20 weeks (after LMP)
And how
small can a baby be born and survive?
We have records of infants born at 10 oz. (280 gm) born at 25-26
weeks (after LMP), of an 11.5 oz. (280 gm) born at 27 weeks, and of a 12 oz. (405 gm) baby
born at 23 weeks.
What of their
quality of life as adults?
The earliest low-birth-weight babies born in the
years of improved survival are now in their teens. In interviews conducted by a panel of
physicians, these teens "view their health-related quality of life as quite
satisfactory." Self-perceived Health Status &
Health-related Quality of Life of Extremely Low Birth Weight Infants at Adolescence, JAMA,
8/14/96, p. 453
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