Ballard test to determine gestational age

The Ballard test is one of the diagnostic tools to calculate gestational age. This technique continues in force in various parts of the world and is applied to newborns.

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Next we will tell you in depth what the Ballard Test is and what its main characteristics are.

What is the Ballard Test?

The Ballard Test is subscribed to neonatology and consists of a clinical technique to determine the gestational age of the newborn. This tool is applied based on various criteria divided between physical and neurological, to which a score is assigned and subsequently added, in order to estimate the age, which is generally between 26 and 44 weeks of pregnancy..

It should be clarified that, although the test is applied in a standard way, a series of variations emerged recently that allows estimating the gestational age in babies from 20 weeks of pregnancy, which are considered preterm born.

Main Features

• The foundation of the Ballard Test is the intrauterine changes that the fetus undergoes as it matures.
• The physical criterias of the Test revolve around anatomical changes.
• The neurological criteria are primarily examined on the basis of muscle tone.
• According to the postulates of the Test, it is considered that infants less than 28 weeks old are in a state of physiological hypotonia, that is, they have decreased muscle tone, a condition that changes in their growth process.
• The Ballard Test is considered to be a synthesis or simplified method of the Dubowitz Test which is made up of 10 neurological and 11 physical criteria.

Ballard Test Physical Criteria

As we mentioned earlier, one of the evaluative components of the Ballard Test is the physical criteria. These criteria are:

• Skin: The newborn's skin is evaluated taking into account the structures of the skin, as vernix caseos is lost, which is that thin layer of fat with which babies are born.
• Pinna: At this point, the change in the configuration of the ear is evaluated, since it increases its cartilaginous content as the baby develops.
• Speed: Here the fine vellocity that appears in the baby during the 24 or 25 weeks is analyzed, before this the neonates lack any type of hair, which is a sign of lack of maturation.
• Plant area: At this point the evaluator analyzes the cracks in the sole of the newborn's foot..
• Mamas: The analysis of the breasts or breast outline, consists of analyzing the tissue of the breasts of newborns that is usually stimulated by estrogens.
• Male genitalia: In the case of male babies, the descent of the testicles into the scrotal sac is analyzed, a process that occurs approximately at week 30.

Neurological criteria 

• Square window: At this point, the flexibility of the wrist and the type of resistance when stretching the extensors in charge are evaluated..
• Position: One of the main evaluation criteria for neurological criteria is the muscle tone of the body. At this point, the most common posture of the baby at rest is analyzed..
• Arm bounce: Here biceps tone is analyzed and the rebound angle generated by stretching the upper limb is measured.
• Popliteal angle: Here the resistance of the knee flexor is measured at the moment of the leg stretch.
• Scarf sign: To check this sign, one of the elbows is brought to the opposite side of the neck, so that it simulates the shape of a scarf.
• Heel to ear: Here we seek to analyze the passive tone in the waist flexors before the extension of the hip muscles.

Ballard test score

In the scoring scheme of the Ballard Test adapted by Dr. J. Ballard, each criterion receives a score from 0 to 5, giving a total estimate of 5 to 50, which is associated with the gestational age of between 26 and 44 weeks.

It should be clarified that, according to the new version of the Ballard Test, -1 is also included, so negative values ​​could be found in the final result. However, the version that is still used in most cases is the traditional test.

Gestational age estimation methods 

At present there are various methods to calculate gestational age using factors other than the various neonatology tests, and that serve as support when interpreting any of the tests.

The parameters that are analyzed even before birth are the last date of the mother's menstruation and ultrasound analysis. Normally in the middle of the Ballard Test, these types of tools are of great help, to eliminate the error bias of the evaluation.

Some alternative techniques that work as a support are: Measurement of the cerebellum, detection of human erythroid antigens, biometric methods, observation of the lens through ophthalmoscopy and electroencephalography.

Effectiveness of the Ballard Test 

In the case of this type of test that does not require mostly instrumentation, there is always a heated debate regarding its effectiveness.. They are considered tests mediated by subjectivity and greatly influenced by the expertise of the person who practices it..  This is why at present, the observed score of the test is usually combined with the ultrasound history carried out at the time of gestation, in order to avoid calculation errors.

However, even with its subjective feature, the Ballard test continues to be used because, broadly speaking, it presents estimated calculations in which there are seldom large error biases. According to the medical community, it is a viable resource to continue using this test due to the precision of the evaluation parameters used..

Broadly speaking, this is what you have to know about him Ballard test. It should be noted that this type of test must be carried out by a health professional suitable for the task.