Wednesday, July 15, 2009

Unimpaired Outcomes for Extremely Low Birth Weight Infants at 18 to 22 Months

**After talking with Helen, I have decided to make a separate post out of this study, which Helen cited in the comments of the previous post, as to make sure it doesn't get lost in another topic.**

Helen Harrison writes:

I have just seen a study In "Pediatrics" from the NICHD entitled "Unimpaired Outcomes for Extremely Low Birth Weight Infants at 18 to 22 Months" which contains some rather shocking (to me, at least) information, indicating that current outcomes are even worse than I thought.

[Gargas, Vohr, Tyson et al. Pediatrics 2009:112-121.]

This study looked at outcomes (both by gestational age and birthweight) of 5,250 children born weighing less than 1000 grams between 1998 and 2001 in NICHD study hospitals in the US.

"Unimpaired" was defined as Bayley Scale scores equal to or greater than 85, a normal neurological exam, normal vision, hearing, swallowing, and walking.

This study offers a new perspective on outcomes since "mild" (and sometimes "moderate")disabilities -- which most of us parents would consider fairly severe -- are lumped in with "normal", "unimpaired" outcomes when neonatologists and other professionals give outcome information to parents.

This is, as many of us have learned the hard way, highly misleading.

So the NICHD researchers set out to record just how many children were actually free of impairment by the criteria above, at age 18 to 22 months.

We parents also know that 18 to 22 months is much too early to determine some pretty devastating outcomes of prematurity -- autism, for example -- so even these numbers may be overly optimistic.

Here's what they found:

Less than 1% of children born weighing less than or equal to 500 grams survived to be normal(that is, "unimpaired" at 18-22 months).

From 501 to 600 grams it is about 5% unimpaired;
701-800 grams about 15 % unimpaired ;
increasing to 24% for infants 901-1000 grams.

By gestational age: <1% at 23 weeks are unimpaired;
< 5% at 24 weeks;
about 15% at 25 weeks, and
about 24% at 27 and 28 weeks.

(I'm reading some of this from a graph so I can't cite exact percentages.)

After 27-28 weeks gestational age, infants born at 1000 grams or less are small for gestational age as well as premature -- an additional risk factor -- and the percentages of unimpaired decline again, so that, for example, less than 20% of children born at 31 weeks weighing 1000 grams are unimpaired.


ThePreemie Experiment said...

I'm going to be copying some of the comments, from the previous post, relating to this study.

ThePreemie Experiment said...

Anonymous said...

RE: Helen's post about Gargas, Vohr, Tyson et al. Pediatrics 2009:

Helen noted that "'Unimpaired' was defined as Bayley Scale scores equal to or greater than 85, a normal neurological exam, normal vision, hearing, swallowing, and walking."

One problem that I have with reading preemie studies is how they categorize disabilities into larger categories. Helen noted that some "mild" or "moderate" disabilities may not be considered "mild" or "moderate" to the person or parent of the preemie who has them.

I have been frustrated with studies that categorize serious but not insurmountable disabilities as severe. When I hear the word "severe," I interpret it as something that would make one perhaps reconsider providing extended support for the baby. For example, if one knew that a child would be in chronic and intense pain with almost 99% certainty, that may change the course of action that I would choose to take in keeping the child alive. What surprised me with some studies that I read long ago is that they categorized the need to wear glasses as a "severe" impairment. At least to me, that's not in the same league as chronic and intense pain or other disabilities that may prevent the person from living independent and/or happy lives.

Consequently, I don't know how to interpret the statistics in the Gargas et al. article when it says that 85% of 25 weekers will have an impairment. If the majority of those impairments can be aided with glasses or hearing aids, then I would interpret the impairments as serious but would not hinder decisions for ongoing support for the neonate.

Are there articles that breakdown the "impairments" so that parents can truly make sound decisions regarding their preemies?

==Kate K.

July 14, 2009 2:27 PM

ThePreemie Experiment said...

Helen Harrison in response to Kate K who wrote:

"What surprised me with some studies that I read long ago is that they categorized the need to wear glasses as a "severe" impairment."

I've never seen anything in the follow-up literature (and I've read most of it) that would label wearing glasses as a "severe impairment."

The study by Gargas et al. does give some specific indications of what they meant by "mild" vs. "severe" impairment and the extent to which each was present in various groups of ELBW children from <23 weeks to 31 weeks gestation.

For example, having an MDI (analagous to an IQ score) of 70-84 was considered a "mild" impairment.

Having CP and needing an assistive device to walk was considered "mild" CP and only a "mild" neurological impairment.

Vision or hearing loss was present in a very small percentage of the mildly impaired children -- about 12%. By contrast, 70-84 MDI (mental development index) was present in 70% of the mildly impaired.

"Mild" neurologic abnormality was present in about 35-40%.

(Keep in mind this is a cohort that includes children up to 31 weeks gestation.)

By the criteria used in this and many other studies, my son would have probably been designated as "mildly" impaired at 18 to 22 months.

Today at 33 years of age, he needs one-on-one adult supervision at all times and has many, many problems of prematurity that seem to us quite severe.

I'll get back with more details on the study as soon as I feed my son his dinner.

More to come...


July 14, 2009 7:03 PM

ThePreemie Experiment said...

Helen Harrison, back again after dinner:

The study I referred to involves 6090 inborn ELBW infants who ranged in birthweight from 401-1000grams.

These babies were born at 19 centers in the NICHD Network between 1998 and 2001, which includes such medical centers as Case Western, Duke, Stanford, UC San Diego, University of Texas,Houston, University of Tennessee, Yale...

Of these 6090 inborn ELBW babies, there were 886 deaths in the first 12 hours and an additional 1132 deaths after the first 12 hours and before discharge. 82 deaths occurred after discharge, for a total of 2100 deaths by 18 months.

5250 children out of the 6090 had outcomes that were known at 18 months,and 3150 survivors were formally evaluated between 18 and 22 months of age.

Children were classified as unimpaired if they had Bayley Scale scores (MDI and PDI) of 85 or above after being corrected for the child's degree of prematurity, a normal neurological exam, normal vision, hearing, functional ability to swallow, and ability to walk.

CP was classified as "mild" if the child was able to walk with an assistive device, "moderate" if the child was able to sit independently or with support, and "severe" if the child was unable to sit with support.

"Mild" impairments were MDI or PDI scores between 70-84; "mild" CP; mild other neurologic impairment, unilateral hearing loss, unilateral blindness, or minor sensory impairment.

Severe NDI (neurodevelopmental impairment) was defined as Bayley scores (MDI or PDI) below 70, moderate/severe CP, bilateral blindness or bilateral hearing loss requiring amplification.

Children who could not be assessed because of severe developmental "delay" were assigned a score of 49.

Of the 5250 infants with known outcomes at 18 to 22 months, 850 (16%) were unimpaired, 1153 infants had "mild" impairments (22%), and 1147 had NDI (neurodevelopmental impairment, i.e., moderate to severe outcomes), with 2100 deaths (40%).
(I know, it doesn't add up to 100% but those are the percentages given in the article.)

Of the infants classified as unimpaired, 4% had MDIs above 115, 96% had MDIs between 85 and 115. Among the mildly impaired children, 68.4% had MDI's between 70-84; 30.4% had DQs between 85 and 115; 1.2% had DQs over 115. 12.4% had a visual impairment, 1.8% had a hearing impairment. 35% had some neurologic abnormality (either mild CP or "tone abnormality" or "other") 85% were walking independently.

The information by gestational age is given in a bar graph that is hard to read precisely, but:
At 23 weeks or less, 1% or below survived unimpaired. At 24 weeks its about 5-8%. It's about 15% at 25 weeks and about 18% at 26 weeks; at 27 and 28 weeks its about 20-25%, and then the "unimpaired" numbers start to go down again at 29-31+ weeks (when the risks of "small for gestational" age start to factor in).

By far, the most widespread disability in this group is cognitive impairment -- retardation and near retardation. This situation may worsen with age in preemies, according to neurologists, who are finding declines in IQ by 9 to 12 points between childhood and adolescence in otherwise unimpaired preemies. (Isaacs,et al. Brain morphology and IQ measurements in preterm children. Brain 2004,127, 2595-2607). A rise in psychiatric problems also occurs at this time, and both the IQ and psych problems are thought to be delayed developmental reactions of the brain to the damaging conditions and treatments surrounding preterm birth -- a negative form of "brain plasticity" as one neurologist (Dr. Mark Scher at Case Western) has described it.

The point is that 18 to 22 months is a bit too soon to talk definitively about "unimpaired" outcome.

I think this is all important information to get out to the moms on the pregnancy boards who think preterm birth is no big deal.


July 14, 2009 10:27 PM

ThePreemie Experiment said...

P.S. from Helen:

If anyone would like to see the the article from Pediatrics please contact me at

The article from Brain is available online for free.

The lecture by Dr. Mark Scher in which he discusses neurological issues in prematurity and neuroplasticity can be found at www.onlinecelibrary

It costs 15$ to download the lecture, and it is technical in places (helps to know about the functions of chloride and GABA in fetal neurons), but still highly informative and relevant to all of us.


July 14, 2009 11:26 PM

Sarah said...

I haven't read all of the comments, but "unimpaired" seems like a great term for the reasons listed, but as a parent of a chronic vomiter who can see, walk, talk, and hear just fine if their child is unimpaired.

It's the one thing that's frustrating about studies. They never ask the parents' opinion.

Sarah said...

that's supposed to say 'ask a parent' by the way. can't type tonight.

Anonymous said...

Helen Harrison to Sarah:

That's right, they don't ask the parents!

And consider this from a neonatologist who frequently inquires of fellow neonatologists at conferences:

"How many of you, if your own child had an IQ of 78, special education needs, and had 'postural tone and movement difficulties,' would consider this a 'mild' or [even] 'moderate' developmental issue?"

According to my neonatologist friend:
"I have never seen a hand go up in the audience."

I'll bet the docs would be stopped in their tracks by chronic vomiting if they actually had to cope with it personally with their own child.

I agree, ask the parents! Ask the experienced parents!


Carrie said...

Sarah, I was thinking along the same line as you. I have a child that has high blood pressure, but by the definition would be considered "unimpaired." The doctors will not say his high blood pressure is because he was a preemie - but they also can't find any reason as to why he is hypertensive.

Helen said...

To Carrie and Sarah:

I wonder if both of you could discuss your children a bit more.

Hypertension is now seen as related to prematurity (or low birth weight) -- part of the "Barker Hypothesis" or "fetal origins of adult disease" model. There is, I believe, a lecture on this by Dr. Avroy Fanaroff, a very well-known neonatologist, on the I haven't downloaded it yet, but intend to do so soon. (it will cost $15 to download)

I've heard lectures on the Barker hypothesis at conferences and it is something we should all be aware of.

My son, age 33, is currently being followed for hypertension, among other things, so I have a personal interest.

Carrie, how old is your son? What is his BP? How/when was the hypertension discovered? Are there any kidney function issues?

To Sarah -- can you describe the circumstances of the vomiting? How old is your child? Any BPD diagnosis?

I have heard from other parents whose preemie children vomit chronically ( for neuro reasons?), others who gag when eating and vomit, and others who vomit in response to stress or asthma/lung issues.

My son did a good bit of projectile vomiting as an infant and then stopped. He only vomits now with shunt malfunction or bowel obstruction -- unfortunately both have become worsening problems recently.

I'd like to hear more about your children's situations if you'd be willing to share the details.


Kristie McNealy said...

It would be really interesting to see a follow up on these same kids that compares the degree of impairment found in the study to the parent's perception of the daily impact of the disability. I totally agree that unless it is their own child, most docs can't fathom how much impact a "small" or "minor" impairment can have on daily life.

Obviously, no classification system for research purposes is going to be perfect. I mean, if we had to choose to lose one thing - sight, hearing, the ability to walk, the ability to eat food by mouth - we'd all probably pick something different because we value different things about living.

Sarah said...

To Helen:

You could link back to my blog, but it's long and mostly borning.

To sum up: He's a former 26 weeker. I had preeclampsia. He was born with severely under developed lungs (the docs often said they were the worst they had ever seen.)

At the University of Iowa where he was born they do not trach until it is the last option. For instance, a trach isn't discussed until a baby is 8 weeks post dates!

But they liberally use steroids.

Anyway, he came home on 2 liters of oxygen 24/7 and a feeding tube. Shortly after he got home, the vomiting began. We were told it was a 'nuisance.'

At 18-22 months, he was delayed but certainly not impaired - fast forward to now and he is clearly mentally impaired. We're hoping to receive a presumptive diagnosis of autism in a few weeks in order to receive services.

He has severe kidney disease and had a kidney stone in the NICU (this is probably due to the way they feed babies at the university, which is aggressive, or it could be due to genetics as his father has them. Either way, pretty damn rare for a kid let alone a baby.) He had to have it surgically removed in the NICU.

Due to that he has severe kidney disease and hypertension. His nephrologist diagnosed him with hypertension when his BPs ran about 120/80 - which looks perfect on an adult but nasty on a 2-year-old. He's now on meds. His nephrologist claims that it is in direct result to his prematurity and that he hopes to educate others in his field about this. He's one of the few who actually checks for it. He wants my son's BP to be down to 100/50 mmHg with medication (still high). A baseline BP for a child would be 80/40 mmHg. My son now runs about anywhere from 80/40 to 100/50. It's much better on the meds. He'll be on it for life. The implications suck as BP meds.

You can google The Fifth Report, which is an extensive study into pediatric hypertension. Prematurity is mentioned in it.

As far as the vomiting - he has severe BPD (though his respiratory issues are now the least of his problems.) The vomiting - who nows where it comes from. He has excessive phlegm but no obvious allergies and he tends to gag on post nasal drip. He also cannot stand any textured foods (sensory issues)in the back of his throat and vomits with them. No foods seem to make him vomit, and it has become behavioral now as he finds that he can change his environment by vomiting (not with dad or me, but certainly with grandparents and nursing staff.)

I consider him severely impaired from his prematurity - he still wears O2 at night, he has a feeding tube, he cannot eat, he vomits at least 3 times a day, he has poor social skills and extremely limited speech, and he still has a weak trunk - though that is thought to be due mostly to respiratory issues.

Oddly enough, he has a few physicians who tell me how 'well' he's doing.

Oh, and he had no brain bleeds and no shunt so the vomiting isn't attributed to that.

Dee said...


I don't know if this is helpful to you at all, but i was reading about this in the last couple of days:

It talks about habitual and conditioned regurgitation of food, and it seems to be most common amongst young children and those with cognitive disabilities.

I agree that the terms "mild" or "moderate" impairment are misleading. They clearly have specific medical definitions, which do not fit with our ordinary english definitions of the words.

Helen said...

To Dee:

The terms "mild" and "moderate" impairment are used differently in different medical studies and this is one reason it is so hard to compare follow-up studies.

What used to be called a "moderate" cognitive deficit (IQ 70-84) is now labeled as "mild." This can give a misleading picture of improving outcomes when studies are compared over time.

Also if the docs lump in "mild" impairment with "normal" outcomes, they give falsely optimistic counseling to new parents, and I think this is unfortunate.

I think it is time for outcomes to be presented in a standardized way with much more information than is given in the usual study -- for example health outcomes and behavioral outcomes really need to be looked at in much greater detail.

I does help, though, for parents to speak out about this. I have been going to conferences for decades now and since the
mid-1990s I have been raising the alarm in comment sessions and published letters about the autism epidemic I see among preemies as reported by their parents on the blogs and lists.

Autism screening for preemies is now becoming part of some follow-up programs.


Helen Harrison said...

To Sarah:

I will check out your blog ASAP, and I must say I would agree with you about the severity of your son's problems!

The vomiting I have personally seen in preemies (aside from my son) has usually been part of BPD and part of an anxiety response. One adult preemie I know is still quite vulnerable to it at age 30 (he had very mild BPD as a neonate, but the vomiting has remained a stress response.)

Kidney stones (and gall stones) are not uncommon in preemies and are listed in some books on follow-up as "known" complications of NICU therapy -- such as diuretics (kidney stones) and TPN (liver, gall stones). However, too many docs still do not know about this.

I hope your son's nephrologist brings the kidney issues,hypertension, etc. out to the entire medical profession.

I *did* see a study on the high incidence of kidney disease in children born prematurely at the SPR (Society for Pediatric Research) conference in Baltimore a few months ago. That's a start. But parents have been talking about it on the Internet for much, much longer -- each thinking his or her child was uniquely afflicted.

Parents need to be told about all these possibilities before they leave the NICU just so none of it totally blindsides them later.

I wish there were a national registry for preemies which would collect this sort of data from every preemie survivor and make it widely known to parents, physicians, and teachers.

As it is, so many families coping with these problems feel isolated and alone, especially with all the "miracle baby" stories in the media. And physicians often do not hear about these things, and, of course, blame the parents for their parenting shortcomings, etc. adding insult to injury.

My daughter is taking a developmental psych class where the textbook makes prematurity sound like a walk in the park where almost everyone is caught up by age two and there are no differences in graduation from high school, employment, marriage, etc. even for extremely preterm infants. This just isn't true, but this is what the new generation of psychologists is being taught.


Carrie said...

re: Carrie, how old is your son? What is his BP? How/when was the hypertension discovered? Are there any kidney function issues?

Helen, Max is now 3 years old. At 1 years old, he had a follow-up echocardiogram done at the local children's hospital. As part of his initial exam they took his blood pressure. It was like 136/90. He also had an ear infection, so they got him antibiotics for the ear infection and followed his blood pressure for a week. It didn't go down - so they started him on medication, isradipine. His bp has been well controlled with medication (4ml twice a day) and he hasn't had any changes in almost 1 1/2 years. His blood pressure now is 100/60.
The echos have all come back totally normal (he has had a total of 3) and his renal ultrasound came back normal too. They want another renal ultrasound done this summer. He did have a urinary track infection while in the NICU. The nephrologist he sees is just baffled by his hypertension especially because he did not have a central line as a preemie.

Helen Harrison said...

To Carrie:

136/90 -- WOW! At age 1! Even with an ear infection...

My son (at age 33 and now overweight) is being looked at for 140/90 on a few occasions in the MDs office (white coat hypertension?) He still runs on the high side when I take it at home, so I'm not totally blaming it on stress.

What did the docs say about the importance of the central line? I had never heard of that being a factor, but I wouldn't be surprised.


Helen Harrison said...

To Sarah:

I just visited your blog and (on a non-preemie related note) thought you did very well with the macro setting and that the garden is quite beautiful.

I do have to wonder how your son would have been categorized in the NICHD study. I can see from the adorable pictures how the docs would say he's doing well. But your commentary shows some major challenges. It sure brought back memories for me.

My son was included in a follow-up study on grade 4 IVH back in the 1970s. He was judged developmentally "suspect," but not impaired.


Sarah said...

To Helen,

That's why I hate the studies. They don't always depict an accurate picture. When I go in and talk with his doctors, I don't quote studies but other parents. For the most part, I do get my point across, but on the other hand I need studies to back up my point. I have one doctor who tells me that he is doing 'great!' But this doc specializes in GI disorders for moderate to severely mentally retarded children and children with severe developmental disabilities. I guess my son would look good compared to his patient load.

This study in particular, though, I think would glamorize my son. Yes he looks really great. I think that's his biggest downfall, but if you talk to other preemie moms, vomiting is a huge issue. Hypertension is rarely discussed, yet it is extremely common in preemies. My son has 9 specialists. We travel to the university about every 6 weeks. That alone I consider 'impaired.'

And for the most part it's not that it bothers me that he is impaired, it bothers me that I have to fight tooth and nail to try to get help.

Anyway, thanks for the garden comments :)

Sarah said...

To Dee:

I don't know if he would fit into the category of Rumination syndrome because he does retch and has nausea. He gags frequently and won't even swallow his secretions.

Very interesting, though.

Helen Harrison said...

If anyone is still reading this thread, I did want to comment on one point raised by Dee who wrote:

"I agree that the terms "mild" or "moderate" impairment are misleading. They clearly have specific medical definitions, which do not fit with our ordinary english definitions of the words."

Unfortunately, there are no specific medical definitions for these words that are consistently used by NICU follow-up studies.

Some doctors (such as Maureen Hack) consider an IQ of <85 to be a moderate handicap, not at all "mild".

The EPICure Group, the NICHD and some other studies have set the bar much lower (<70) for "moderate".

On the other hand,the EPICure Group uses a current term-born control group to set the norm for testing which gives a far more realistic view of what is actually going on.

The NICHD Group has no term-based norms, though perhaps in infancy this is not as relevant as it will become in later life. I hope the NICHD docs use term-born controls to set norms for testing as time goes by.

There are many variables in how doctors decide to categorize types of disability and what they count and don't count as a disability: seizures? shunts? oxygen dependency in childhood? feeding tubes?, etc. -- it all depends and varies widely from study to study.

(who has been off camping in the wilderness with DH and DS for the last 4 days)

Dee said...

Thanks Helen for that insight into the terminology used. I must admit i am a little bit horrified that these words are used in a medical context without any kind of consistency being applied.

I had assumed that there were defined meanings, as I recalled the different "categories" of intellectual disability based on IQ that I learned when I studied psychology (many years ago). These were very clearly delineated, although that in itself is probably a topic for much further discussion and criticism.

terri w/2 said...

Helen said:

"My daughter is taking a developmental psych class where the textbook makes prematurity sound like a walk in the park where almost everyone is caught up by age two and there are no differences in graduation from high school, employment, marriage, etc. even for extremely preterm infants. This just isn't true, but this is what the new generation of psychologists is being taught."

Helen - it IS SO FRUSTRATING!! I just finished nursing school two years ago, and had an OB rotation. The instructor was a pro-life supporter who talked SO glowingly about how her hospital will save 22 weekers regardless of the wishes of the parents, like that is a good thing. (Those terrible parents). NOTHING about the myriad of horrifics that ensue - the lengthy hospitalizations, massive complications, life-long disabilities. She talked about a couple who had had 22 weeker twins, both with brain hemorrhages, "but they're doing well now". .although when she said this, they were still in the NICU. The information in our OB book talked about the reasons for prematurity, and smoking was #1. It was a frustrating, horrible nursing class, and I felt for most of the semester that I was on the brink of having an IVH myself. One can only fight so much before the instructor gets damn sick of the "know it all" in the class. .

Another group to take on - the professional textbook industry!

Helen Harrison said...

Speaking of books--

I highly recommend the recently published book by Vicki Forman, mother of 23 week twins, entitled "This Lovely Life"
(Mariner Books, Houghton Mifflin Harcourt, 2009).

Vicki was recently interviewed on
Her interview may still be available at:

I highly recommend the interview and book to preemie parents!

The book was also given a rave review in the latest New England Journal of Medicine, with the physician-reviewer concluding:

"This book should be required reading for all staff members who are involved in the delivery and treatment of high risk infants."

support for parents of preemie babies said...

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