What is a gestational assessment?
Assessing a baby's physical maturity is an important part of care. Maturity assessment is helpful in meeting a baby's needs if the dates of a pregnancy are uncertain. For example, a very small baby may actually be more mature than it appears by size, and may need different care than a premature baby.
An examination called the Dubowitz/Ballard Examination for Gestational Age is often used. A baby's gestational age often can be closely estimated using this examination. The Dubowitz/Ballard Examination evaluates a baby's appearance, skin texture, motor function, and reflexes. The physical maturity part of the examination is done in the first 2 hours of birth. The neuromuscular maturity examination is completed within 24 hours after delivery.
How is physical maturity assessed?
The physical assessment part of the Dubowitz/Ballard Examination examines physical characteristics that look different at various stages of a baby's gestational maturity. Babies who are physically mature usually have higher scores than premature babies.
Points are given for each area of assessment, with a low of minus one or minus two for extreme immaturity to as high as plus 4 or plus 5 for postmaturity. Areas of assessment include the following:
Skin textures (for example, sticky, smooth, peeling)
Lanugo. This is the soft downy hair on a baby's body. It is absent in immature babies, then appears with maturity, and then disappears again with postmaturity.
Plantar creases. These creases on the soles of the feet range from absent to covering the entire foot, depending on the maturity.
Breast. The thickness and size of breast tissue and areola (the darkened ring around each nipple) are assessed.
Eyes and ears. Whether or not eyes are fused or open, and the amount of cartilage and stiffness of the ear tissue are noted.
Genitals, male. The presence of testes and appearance of scrotum, from smooth to wrinkled, are assessed.
Genitals, female. The appearance and size of the clitoris and the labia are assessed.
How is neuromuscular maturity assessed?
Six evaluations of the baby's neuromuscular system are performed. These include:
Posture. How the baby holds his or her arms and legs.
Square window. How far the baby's hands can be flexed toward the wrist.
Arm recoil. How far the baby's arms "spring back" to a flexed position.
Popliteal angle. How far the baby's knees extend.
Scarf sign. How far the elbows can be moved across the baby's chest.
Heel to ear. How close the baby's feet can be moved to the ears.
A score is assigned to each assessment area. Typically, the more neurologically mature the baby, the higher the score.
When the physical assessment score and the neuromuscular score are added together, the gestational age can be estimated. Scores range from very low for immature babies (less than 26 to 28 weeks) to very high scores for mature and postmature babies. However, the score might not be accurate in very low birth weight preterm infants (birth weight less than 1500 grams).
All of these examinations are important ways to learn about your baby's well-being at birth. By identifying any problems, your baby's doctor can plan the best possible care.