The Ballard test It is a medical technique based on the interpretation of certain physical and neurological parameters of a newborn to estimate the gestational age of this. It is also known as 'New Ballard Score' (New Ballard Score).
It is applicable in the postnatal stage and is especially useful when there is no prenatal data, that is, the mother is not clear on the date of her last menstruation (FU) and there is no record of ecosonographic studies during pregnancy..
The physical criteria are nothing more than the observation of certain anatomical structures of the newborn, these are: the skin, the pinna of the ear, the presence or absence of lanugo, the surface of the sole of the feet, the breast outline or the genitals.
Meanwhile, the neurological criteria are directly related to the observation of the baby's muscle tone. Preterm newborns are usually hypotonic, but full-term babies are not.
Each observed characteristic represents a score, and the total sum of the points indicates how many weeks of gestation the baby was at the time of birth..
The original technique of the Ballard test allowed evaluating from 22 weeks onwards. However, there is an update of the test that has allowed obtaining more specific data from 20 weeks, that is, in even more premature newborns.
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The study or Ballard test was a modification of another technique that was also used to estimate gestational age, which was called the Dubowitz test. The modification was made by Dr. Jeanne L. Ballard along with other researchers.
This test consisted of the analysis of 21 criteria (11 physical and 10 neurological). The Ballard test is a reduced method of the latter.
However, the first technique proposed by Ballard had 2 drawbacks, since it overestimated the gestational age in extremely premature newborns (< de 28 semanas, especialmente de muy bajo peso) y al mismo tiempo sub-estimaba la edad en los bebés nacidos después de término (> 40 weeks).
Later, in 1991 it was modified and was called New Ballard Score (NSB). The modification was assertive to assess extreme preterm infants. Being able to determine the gestational age from 20 to 44 weeks of gestation with greater precision.
In the past, this was the most frequent way to measure gestational age, since ultrasound studies were not available as today.
At present, these tests are only performed when there are no specific prenatal data, that is, it is used when the date of the last period is not known and there has not been a control under the use of ultrasounds. It should be noted that the modified Ballard test is recommended by the Academy of Pediatrics.
The Ballard test is performed in newborns, almost always within the first 24 hours of life, however, it is applicable up to 4 days thereafter. In very premature children it is recommended to apply before 12 hours.
The test has two stages, the observation of 6 physical and 6 neurological parameters. There is a table that describes each phase and each parameter in which 6 to 7 possible characteristics appear, each one is weighted with a specific score, ranging from -1 to 5.
The specialist, after evaluating and weighing all the parameters in each stage of the test, adds up the points obtained. The result is entered in a formula that is the following:
Gestational age = [(2 x score) + 120] / 5
Subsequently, the result is located in the following table, corresponding to the Ballard scale or also called the New Ballard Score.
The skin provides a lot of information about the maturity of the baby. The more premature it is, the skin will be brittle, soft, thin and transparent, to the point of being able to see blood vessels. Whereas, as the baby is more mature, the skin tends to be thicker and wrinkled. It should be rated according to the Ballard rating table.
Lanugo is like a very fine hairy film that can be seen in the fetus and in premature babies, therefore, its presence is a sign of immaturity.
The doctor will measure the length of the foot taking into account from the big toe to the heel. Other characteristics such as folds and their proportion can also be observed. The fewer folds, the more immature.
In this parameter, it is necessary to evaluate whether or not the areola is observable, as well as its characteristics, together with the presence and size of the mammary gland. The absence of both is a sign of immaturity.
The eyes are observed if they are closed subtly, so that they can be opened easily or if, on the contrary, they are strongly fused. Another important parameter to observe is the curving of the pinna and the strength or fragility of the cartilage of the ear..
The characteristics of the genitalia are also of great help for estimating gestational age, specifically the anatomy of the same is observed, being distinguishable the shape of the scrotum, the presence or absence of testicles, the shape and size of the clitoris, labia majora and minors, among other characteristics.
In this case, the specialist lays the baby on a flat surface on his back and observes whether his posture presents the lower limbs straight or, if on the contrary, they are bent in an arch.
The specialist will flex the baby's wrist very carefully and observe the angle that forms between the hypothenar eminence (lateral area of the palm of the hand) and the ventral part of the forearm. The angle ranges from 0 ° to> 90 °.
With the baby lying on his back, the baby's arm is flexed on his forearm, then it is fully extended and immediately released. It is observed if the arm remains extended or if it returns to the flexed position. Then score according to the Ballard rating table.
Continuing with the baby in the position on his back, now the baby's leg is flexed trying to join the knee to the chest and in that position extend the leg as far as possible. The popliteal space (hamstring) is measured.
With great care one of the arms of the baby is taken and it is tried to happen through the neck until it touches the opposite shoulder or beyond. The ability of this in this feat is evaluated.
In this last test, with a completely flat pelvis and extreme delicacy, the child's foot is taken and an attempt is made to reach the head, without forcing too much. During the feat, the knee will be located on one side of the abdomen. The result obtained according to the Ballard table is noted.
The Ballard test, as well as other similar tests such as the Dubowitz, Capurro or Usher test, are useful to assess the gestational age of a newborn.
However, Ballard's is one of the most accurate and has the advantage that it can be applied to children who need to be connected to an assisted breathing apparatus..
Some countries prefer the use of the Capurro test as in Ecuador and other Latin American countries, but in the United States they use the modified Ballard test more..
This information is necessary to make certain therapeutic decisions regarding the affectations that the newborn may present, especially if it is premature, since gestational age establishes the state of maturity of the newborn's organs..
With this information the doctor can predict risks, suggest special care and prevent future complications.
Based on gestational age, the newborn is classified as premature, late preterm, early term, full term, late term, post term or post mature. (See following table)
The disadvantage of these types of tests is that they depend a lot on the observer, therefore, they are very subjective. This means that two specialists could give different results against the same newborn..
However, if the test is performed by an experienced neonatologist, the reliability and concordance rate with other methods is approximately 90%..
In this sense, Marín and collaborators in 2006 carried out a study where they correlated the modified Ballard test with those obtained in the studies of ecosonograms and the date of the last rule..
They obtained a good correlation between the compared methods. The difference obtained was 2 weeks between prenatal methods (ECO / FUR) and postnatal (modified Ballard test).
They also concluded that a higher gestational age tends to be designated when it is evaluated by the Ballard test method, especially when mothers are treated with corticosteroids and / or in the case of very premature babies.
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