Gestational age assessment means figuring out the number of weeks of your pregnancy. A full-term pregnancy is usually 40 weeks. It's important to assess if gestational age is uncertain or if your baby is smaller or larger than expected.

The Ballard score is commonly used to determine gestational age. Here's how it works:

• Scores are given for 6 physical and 6 nerve and muscle development (neuromuscular) signs of maturity. The scores for each may range from -1 to 5.
• The scores are added together to determine the baby's gestational age. The total score may range from -10 to 50.
• Premature babies have low scores. Babies born late have high scores.

The physical assessment includes an exam of the following physical characteristics:

• Skin texture. Skin may be sticky, smooth, or peeling.
• Lanugo. This is the soft downy hair on a baby's body. It's absent in premature babies. It's present in full-term babies, but not in babies born late.
• Plantar creases. These are the creases on the soles of the feet. They range from absent to covering the entire foot.
• Breast. The thickness and size of the breast tissue and the areola (the darkened area around each nipple) are assessed.
• Eyes and ears. Eyelids are checked to see if they are open or fused shut (more likely in a premature baby). The amount of cartilage and stiffness of the ear tissue are also noted.
• Male genitals. The presence of testes and the look of the scrotum, from smooth to wrinkled, is verified.
• Female genitals. The appearance and size of the clitoris and the labia are noted.

The neuromuscular assessment includes an exam of the following:

• Posture. How the baby holds their arms and legs.
• Square window. How far the baby's hands can be flexed toward the wrist.
• Arm recoil. How well the baby's arms spring back to a flexed position.
• Popliteal angle. How well the baby's knees bend and straighten.
• 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.

Gestational age assessment is an important way to learn about your baby's well-being at birth. By identifying any problems, your baby's doctor can plan the best possible care.