Newborn Screening Test in California

 What is The Newborn Screening Test?
My Current Recommendation
Risks andBenefits
The Law
When to Have the Heelstick Done
Phenylketonuria (PKU)
Galactosemia
Congenital Hypothyroidism
Sickle Cell Disease and other Hemoglobin Diseases (Hemoglobinopathies)
Limitations of Screening

What is The Newborn Screening Test?

The Newborn Screening Test is an analysis of the baby's blood to look for evidence of certain genetic diseases or inborn errors of metabolism.  The test is performed by collecting a blood sample from the baby onto special paper, which is then sent to a laboratory for analysis of red blood cells, hormones and metabolic by-products to assess whether the findings are outside the normal range.

Update - There is a new device for getting blood from the baby that many midwives say is significantly more humane than older methods.  It's the Tenderfoot device, and more comments are recorded in the Midwife Archives section on Newborn Screen/PKU/Heelsticks.  After I've had a chance to try them out, I'll revise these pages accordingly.

Typically, the blood sample is taken from the baby's heel by means of a heelstick.  This is a procedure in which a small blade is jabbed into the baby's heel so that drops of blood will collect and drip onto the test paper.  The test paper usually has five one-inch circles which must be filled with blood; this can take 30 minutes in a dehydrated baby at 24 or 36 hours, or it may take just a minute or two in a well-hydrated baby at day 5 or 6.

[Newborn Screening Program FAQ from the California Department of Health Services and their information page - About the Newborn Screening Test: Important Information For Parents.]
 

My Current Recommendation

Like many parenting decisions, the decision whether to have your baby subjected to a test that inflicts almost certain pain with a very small chance of benefit is a difficult one.  There is very little clinical data regarding the baby's experience of pain and the long-lasting psychological and emotional effects of a traumatic heelstick.  This is an area where I do not have enough information to make a real recommendation to parents.  I can only share the information and ask them to seek within their hearts for the answer for this baby.

How do you compare the certain pain of a heelstick to the 1 in 4000 chance that the baby may benefit from this test?  If you could somehow connect all the risk with all the benefit in one baby, what would it look like?  Suppose each baby who would benefit from this test would only benefit if they had 4000 heelsticks?  4000 heelsticks is about one heelstick a day for each day of the first ten years of a child's life.  What would that baby choose?  Having seen a number of horribly traumatic heelsticks, I think the choice I would make if I were that baby would be to live a life with the consequences of hypothyroidism or retardation from PKU rather than to live each day in dread of the next torture session.  But this choice changes if the heelstick can be done more humanely.

My thoughts on this subject change frequently, and I cannot pretend to know the answer for parents making this choice for a specific baby.  Right now, if I were making this decision for my own child, I think I would choose to have the heelstick done to collect blood for the newborn screen only if the heelstick can be done humanely.  This is ideally a heelstick done at day 6 by someone who is willing to take the time to warm the baby's heel and wait for the baby to be in a sleepy state so that the experience of pain is minimized.

Some midwives claim that the test can be performed with very little discomfort to the baby.  The process they describe involves feeding the baby and warming the baby's heel so that the blood flows easily; this approach requires about a half hour of preparation, and the stabbing/bleeding event takes relatively little time.  If you are taking your baby to an institution where the practitioners do not have the half hour to spend warming the baby and waiting until the baby is fed and relaxed, you can make a point of doing this yourself before the test.
 

Risks and Benefits

Risks

Since nothing is injected into the baby, the primary direct physical risk is the very small risk of infection caused by breaking the baby's skin.  This risk can be minimized by: There is also a very small risk of injuring a nerve in the baby's heel if the test is performed improperly.

In addition to the direct physical risks, there is a secondary physical risk in disruption of the breastfeeding relationship.  If the heelstick is done when the baby is quite young, the trauma caused by the heelstick could cause difficulties with breastfeeding and deprive the baby of the superior immunological and nutritional qualities of breastmilk.  This risk can be minimized by postponing the heelstick until the mother's milk has come in, and the mother/baby breastfeeding relationship is well established (usually by day 5 or 6).

One of the risks that standard medical research tends to overlook is the risk of emotional trauma to the baby caused by a brutal, prolonged heelstick.  In the first hours after birth, the baby is making a number of physiological adjustments; in particular, the baby must start getting all its fluids from the liquids ingested into the stomach instead of from the umbilical cord.  During the changeover period in the days immediately after birth, it is very common for a baby to be mildly dehydrated.  Although this mild dehydration is not usually a threat to the baby's health, it can make getting a blood sample from the heelstick very difficult because the blood is not flowing freely.  When caregivers share their "secrets" to getting blood from a newborn's heel at 24 or 36 hours, they are usually talking about stabbing deeper or more times in order to get the blood to flow more freely or more quickly.

Despite repeated, deep stabbing, getting a blood sample for the newborn screen from a dehydrated baby at 24 or 36 hours can take up to a half hour in which the baby's screams indicate that the baby perceives this procedure as very painful.  Given that this pain is being intentionally inflicted by another human being, this may seem like brutal torture from the baby's point of view.  For a baby who is only 24 hours old, this can represent 2% of the baby's entire extrauterine life.  Given the way in which humans tend to remember traumatic events, this kind of trauma very early in a baby's life can alter a baby's behavior or future emotional development.  I have also seen firsthand how this experience affects the mother-baby bond; mothers watching their baby tortured must disconnect emotionally from their baby in order to remove themselves from the intense pain.  I cannot imagine how much the baby's trust is damaged by having this test performed while her mother does nothing to stop the pain.
 

[Pioneering work in the field of Birth Psychology and Birth Trauma is being done by members of APPPAH, the Association for Pre- and Perinatal Psychology and Health.]  Some related articles and abstracts are available online:

Babies Remember Pain by David B. Chamberlain Ph. D.

My granddaughter Bevin, at age 2, while talking about her birth experience, asked her parents, "Why did they poke me with a thing?" Her mother asked, "What thing?" "Like a pencil," she said. "They hurted me." She was probably referring to the heelstick. . .
A couple of pioneering works in the area of infant pain:

Pain in infancy: neonatal reaction to a heel lance.
Owens ME, Todt EH
Pain 1984 Sep;20(1):77-86

Pain expression in neonates: facial action and cry.
Grunau RV, Craig KD
Pain 1987 Mar;28(3):395-410

[ NOTE - The State of California's Newborn Screening Program uses normal ranges of test results based on blood obtained with heelsticks only.  Thus they would consider that blood for the newborn screen is only appropriately obtained via heelstick.  They specifically exclude the use of IV lines or capillary tubes in the collection of blood for the newborn screen.  Given this serious restriction, it would be nice if they put more energy into supporting humane collection of blood for the newborn screen by educating parents and healthcare providers about ways to reduce the baby's experience of pain from this procedure.]

The baby's experience of pain caused by the collection of blood may be reduced by drawing blood as in a traditional venipuncture instead and by using topical anesthetic at the site of the venipuncture.

[The routine sampling procedure for PKU should be changed. Venous puncture is less painful than heel lancing].
Larsson BA, Norstmo A, Guthenberg C, Olsson GL, Danielsson P, Hagenfeldt L, Elander G, Larsson A
Lakartidningen 1997 Dec 3;94(49):4625-8 [Article in Swedish]
"Because it is unnecessarily painful, however, this form of sampling in newborns has recently been questioned. There is reason to recommend sampling from a dorsal hand vein as the method of choice for PKU screening purposes."

Venipuncture or heel lancing for neonatal blood testing.
Rao G
J Fam Pract 1998 Aug;47(2):93-4
"Venipuncture is more effective and less painful than heel lancing for blood tests in neonates."

Alleviation of the pain of venipuncture in neonates.
Larsson BA, Tannfeldt G, Lagercrantz H, Olsson GL
Acta Paediatr 1998 Jul;87(7):774-9
"EMLA significantly reduces the pain caused by venipuncture on the dorsum of the hand and does not complicate puncture of the vein."

NOTE - More skill is required to perform a newborn venipuncture than a newborn heelstick, and this skill level may not be available in all facilities that perform newborn screening tests.  Also, according to the California Department of Health Services, blood collected from a dorsal hand vein yields phenylalanine levels lower than if collected from the heelstick; providers interpreting the results of the test must be alert for high levels still within the normal range for a heelstick, understanding that the Program cutoff levels are based on heelstick levels. Thus a sample collected from the baby's dorsal hand vein might be evaluated as normal by the Program but truly indicate a problem. [See Newborn Screening News - Special Bulletin (11/97) ]

Unfortunately, topical anesthetic creams do not appear to lessen the pain of a heelstick:

Does a local anaesthetic cream (EMLA) alleviate pain from heel-lancing in neonates?
Larsson BA, Jylli L, Lagercrantz H, Olsson GL
Acta Anaesthesiol Scand 1995 Nov;39(8):1028-31

In addition to reducing the pain of the experience itself, the baby's experience of pain may be reduced by swaddling afterwards (and perhaps even during):

Swaddling after heel lance: age-specific effects on behavioral recovery in preterm infants.
Fearon I, Kisilevsky BS, Hains SM, Muir DW, Tranmer J
J Dev Behav Pediatr 1997 Aug;18(4):222-32
 

Benefits

There is significant life-enhancing benefit to the baby if the newborn screen detects a condition which can be treated in order to prevent serious, permanent consequences, such as neurological damage.  The chance that the Newborn Screen will provide this benefit is about 1 in 4000.
 

The Law

California State Law requires that the Newborn Screening Test be done before a baby is six days old.  The only exception is a waiver for religious reasons*.
 

When to Have the Heelstick Done

Newborns tend to be dehydrated in the first couple of days after birth.  This dehydration makes it more difficult for blood to flow freely from a heelstick.  The baby's hydration levels tend to return to normal by day 5, after the mother's milk has come in and the baby has adjusted to getting fluids from its stomach rather than the umbilical cord.

Some tests are less accurate when done before 5 days of age, and it is often recommended that a repeat test be done at 1-2 weeks of age if the first test was done before 72 hours.  Some of the diseases tested for have such obvious symptoms that the baby would exhibit symptoms even before the test results are available (galactosemia, hypothyroidism).

For families that choose to have the Newborn Screening Test performed on their baby, they may want to obtain the maximum benefit for the baby with the minimal discomfort.  For these families, the best approach is to locate a sympathetic care provider who will take the time necessary to minimize the trauma to the baby, and arrange to have the test performed when the baby is six days old.  Families should make inquiries and arrangements before the birth, as the timing of the tests is important.

Ideally, families could locate a care provider who would come perform the test in their home, so as to avoid exposing the immunologically vulnerable newborn to germs in the hospital or provider's office.
 

Different states test for different diseases, although all states test for PKU (Phenylketonuria) and hypothyroidism, and most states test for galactosemia and hemoglobinopathies.
 
 

The California Newborn Screening Test tests for:

 This section discusses the incidence of the disease and the importance of the timing of testing.
 

Phenylketonuria (PKU)

Phenylketonuria (PKU) is caused by an inability to metabolize the common amino acid, phenylalanine, due to a lack of the enzyme phenylalanine hydroxylase. PKU can result in severe, permanent, neurological and developmental problems.  Incidence - 1:10,000 – 1:15,000 "caucasian" births (less common in other races) [California, 1995, 1:25,934 for classical PKU; 1:28,849 of a PKU variant].

TIMING – Severe cases of PKU can be detected from cord blood; milder cases may not be detected in a breastfed baby until the mother’s milk has been in for at least 48 hours.  Levels of phenylalanine in mature breast milk (after several weeks) are so low that mild cases of PKU would not be detected.  Some parents opt to have the cord blood tested and then to retest the baby with a urine test at 4-6 weeks of age, figuring that the cord blood test will detect severe cases, and the urine test at 4-6 weeks of age will detect mild cases before they cause permanent damage.  (This approach works particularly well for breastfed babies because mature breastmilk is naturally low in phenylalanine; in fact, it is so low that very mild PKU may not be detected at 4-6 weeks.  So parents taking this approach may want to consider re-doing the urine test after the baby has started eating solid proteins.)

NOTE - The newest tests for PKU disorder are sensitive enough that they can accurately detect PKU from cord blood.  [From the Newborn Screening News, the newsletter of The California Newborn Screening Program, Summer, 1996, p. 7]

Question: How long after a protein feed must we wait before collecting the NBS specimen so that the PKU screen is valid?

Answer:  A protein feed is not necessary before collecting the NBS specimen.  A newborn has been receiving phenylalanine in utero. California's laboratory testing methodology is a very sensitive quantitative one that does not require a further protein challenge.  Therefore, follow the guidelines as outlines in this newsletter for collecting specimens after 12 hours of age.

 However, the very next paragraph ignores this information:
Question:  I noticed the NBS specimen collection form has a box for CORD BLOOD, does this mean that we can use cord blood rather than stick the newborns?

Answer: NO!  You should only submit cord blood to the NBS Program if a newborn has been transfused prior to the heelstick NBS collection.  If you still have available a nonhemolyzed cord blood specimen that is also free of clots, you can spot it on the filter paper, identify the specimen as cord blood and report the specimen collection date and time to be the same as the birth date and time.  The combination of a cord blood specimen (valid for the galactosemia and hemoglobin screens) and the 24-hour post transfusion specimen (valid for the PKU and hypothyroidism screens) will allow you to obtain a complete screen for a transfused newborn.

So, the materials from the state are a little schizophrenic on the subject of cord blood.  This is somewhat ironic, because the test that provides unreliable results from cord blood is the test for hypothyroidism, which still provides unreliable results for the first few days after birth, which is when most babies are tested.  Waiting two days after birth to test for hypothyroidism doesn't provide greatly increased reliability; test results would be nearly as reliable if all newborn screening were done from cord blood.

Galactosemia

Galactosemia is caused by one of two different metabolic disorders – both cause an inability to metabolize galactose, which is one of the milk sugars.  Galactosemia can harm the baby’s eyes, liver and brain.  Incidence 1:60,000 for galactosemia and 1:150,000 with galactokinase deficiency. Hereditary recessive. [California, 1995, 1:80,904].

According to the California Department of Health Services, galactosemia can be detected from cord blood.  [See Newborn Screening News - Summer, 1996 ]

TIMING – The timing is almost irrelevant, as symptoms of the disease frequently appear before the test results are available.  Symptoms include cataracts, failure to thrive, vomiting, diarrhea, hypoglycemia, jaundice, liver damage, and an enlarged spleen.  Severe cases can be detected from cord blood; milder cases may not be detected unless the mother’s milk has been in for at least 48 hours.
 

Congenital Hypothyroidism

Congenital Hypothyroidism is caused by low thyroid levels that can lead to retardation.  Incidence - 1:4,000. This is a random rather than a recessive disease. [California, 1995, 1:3,277].

TIMING – Newborn thyroid levels fluctuate the first few days, so screening before 72 hours may yield false results.  It is possible to test cord blood, although the expected values for T4 levels at birth, 24 hours and 72 hours are all different.  As with older children and adults, newborns exhibit symptoms of  hypothyroidism, such as low body temperature, constipation, hypoactivity, lethargy, poor feeding.  In addition, hypothyroid newborns often have a large posterior fontanelle, respiratory distress, blue skin tone, abdominal distention or vomiting, edema and jaundice after 3 days of age. Programs relying on blood collected before 48 hours will have a false-negative rate of about 10%, i.e. they will fail to detect problems in 10% of newborns.  "It is highly desirable that the blood be collected when the infant is between 2 and 6 days of age. . . .6% to 12% of patients with CH are normal on the initial screening test and abnormal on a repeat test." [American Academy of Pediatrics - Newborn Screening for Congenital Hypothyroidism: Recommended Guidelines (RE9316)]

Epidemiology of congenital hypothyroidism.
Klett M
Exp Clin Endocrinol Diabetes 1997;105 Suppl 4:19-23

Neonatal screening in early discharged neonates mostly is not recommended before day 4.
Although the false negatives described above are more serious because they provide a false sense of security, false positives can also create a great deal of stress for a family with a new baby.  Testing before Day 6 has a higher rate of false positives because the baby's TSH levels naturally fluctuate significantly in the first few days and may register as abnormally high.

[Neonatal screening for congenital hypothyroidism].
Moslinger D, Frisch H, Strobl W, Stockler-Ipsiroglu S
[Article in German]

As TSH is physiologically high during the first 2 days of life, the trend to early hospital discharge will result in a significant increase of the recall rate in future.
 

Sickle Cell Disease and other Hemoglobin Diseases (Hemoglobinopathies)

Sickle Cell Disease and other Hemoglobin Diseases (Hemoglobinopathies) are disorders or diseases caused by abnormalities in the structure or production of hemoglobins..  This test is mainly a screen for sickle cell anemia (SCA). Incidence – 1:400 in African American, lower in other groups. Also tests for beta thalassemia, or hemoglobin C.  [California, 1995, 1:4,508 for sickle cell disease; 1:26.925 for other clinically significant hemoglobinopathies].

According to the California Department of Health Services, hemoglobinopathies can be detected from cord blood.  [See Newborn Screening News - Summer, 1996 ]

TIMING – Testing can be performed on cord blood or blood collected at any time.
 

Limitations of Screening

The American Academy of Pediatricians states that: "screening does not equate with diagnosis. Some infants with disorders included in the newborn screening battery will be missed, even when properly screened, due to individual or biological variations.  Other infants may be missed due to administrative or laboratory error. Although the pediatrician cannot be held responsible for these problems, he or she must recognize that any child with a negative newborn screening test may still be affected by one of those disorders. The pediatrician should trust his or her clinical judgment, even in the face of a normal newborn screening report, and should carry out appropriate diagnostic testing if indicated by clinical signs and symptoms."
 


Information from the Midwife Archives


* Many families may have religious beliefs that prohibit performing a test that causes certain pain and risk of infection in a newborn, even if the test could detect a very rare, preventable disease.  Or they may believe that alternative methods of testing or assessing the baby are the best way to fulfill their religious responsibilities to protect their baby from harm.



This information provided by Ronnie Falcao, LM MS


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