Causes of incomplete skull halo

The skull is a layer of bone outside the brain, which is equivalent to a protective layer of the brain. Many of us have never heard of the skull halo, but obstetricians and gynecologists and pregnant mothers certainly know that the skull halo refers to the development of the fetus. The skull halo can be seen through B-ultrasound examination. A complete skull halo indicates that the fetus's head is well developed and there is no bulging or defect.

We all know that we must go to the hospital for a check-up after pregnancy, and we must go for a check-up regularly. In the early stages, B-ultrasound can only show a small ball of flesh, which is called a fertilized egg. However, as time goes by, he will slowly turn into a baby, growing a head, small hands, small feet, and so on. When the baby grows the necessary organs, the doctor will check them all. But, do you know that there is something called fetal skull halo? I have never heard of it before. What is it?

The skull is located above the spine and is composed of 23 flat and irregular bones of varying shapes and sizes (the three pairs of ossicles in the middle ear are not included). Except for the mandible and hyoid bone, the other bones are firmly connected to each other by sutures or cartilage, playing a role in protecting and supporting the brain, sensory organs, and the initial parts of the digestive and respiratory organs. The skull is divided into two parts: the brain skull and the facial skull. The brain skull is located at the upper back of the skull and contains the cranial cavity that holds the brain, which consists of 8 parts. The facial skull is the front and lower part of the skull, including the orbits, nasal cavity, and oral structure, which form the support of the face, with a total of 15 pieces. This is the technical term for ultrasound diagnosis. A complete skull halo means that the fetus's skull is developing normally. If it is incomplete, it is what is medically known as anencephaly or other congenital dementia. The biparietal diameter is the maximum distance between the left and right sides of the head. In ultrasound diagnosis, the distance of the biparietal diameter is closely related to the gestational age. The biparietal diameter is 9.0cm, which is generally around 39 to 40 weeks of pregnancy. If the date you remember matches it and combined with other diagnoses in the ultrasound report, the doctor will tell you whether your baby is developing normally. The normal size of the fetal lateral ventricle should be less than 1 cm, 1 to 1.5 cm is considered mild, and more than 1.5 cm is abnormal. During the rapid growth period of the fetus, the development of the fetal brain is sometimes faster than the aqueduct system in the brain. When the amount of cerebrospinal fluid produced in the brain is significantly greater than the circulation capacity of the aqueduct system, slight expansion of the ventricular system will occur. If the B-ultrasound examination happens to be performed during this period, the examination results cannot be used as a definitive diagnosis of hydrocephalus. Because this slight expansion will gradually disappear as the aqueduct system in the brain develops and improves. The skull halo is intact and the midline of the brain is centered, indicating that the skull is developing normally and there is no hydrocephalus. If the result of the pregnancy checkup shows that the skull halo is intact, it means that the brain of the baby in our belly is developing normally. This is the B-ultrasound display of the fetal skull development. This is a normal health condition, which means that the fetus's head development is normal. However, it is still recommended to pay attention to rest and have regular prenatal checkups.