CTD during pregnancy, by week of pregnancy
The coccyx-parietal size of the fetus is an important indicator that can tell a lot about the development of the baby. This is one of the main parameters that the doctor is interested in at the first screening. Determination of CTE during pregnancy helps to most accurately establish the correct due date.
How does the CTE grow by weeks of pregnancy?
CTE is the distance from the crown of the fetus to its tailbone. It is determined by ultrasound examination and is measured in millimeters. This indicator has a diagnostic value in the period from 6th to 14th weeks. Until the 6th week, it cannot be determined, since the embryo is still too small, and after the 14th week, other parameters become more important.
CTE during pregnancy is measured when the baby is at rest.
The size of the CTE is not affected in any way by the sex of the fetus, its race and other individual characteristics. It depends only on the gestational age, so measuring the CTE is a great way to establish an exact date for women with an irregular cycle.
On average, the CTE has the following indicators, in mm:
- 6-7 weeks – 5 to 11;
- 8 weeks – 12 to 22;
- 9 weeks – 16 to 27;
- 10 weeks – 24 to 38;
- 11 weeks – 37 to 54;
- 12 weeks – 42 to 59;
- 13 weeks – from 51 to 75;
- 14 weeks – 63 to 89.
Only a doctor with an ultrasound examination can set the deadline to the nearest day. To most accurately determine the CTE, the specialist measures it at the moment when the embryo straightens as much as possible.
The longer the gestation period, the more intensively the child grows. Even if in the first weeks he was slightly behind in growth, by the end of the first trimester the embryo grows more rapidly, increasing in size every day.
If the CTE is above average, it can be assumed that a large baby weighing more than 4 kg will be born.
If the indicators, on the contrary, do not even reach the lower limit of the norm, this may indicate the following:
- The woman had late ovulation, in which case the true term will be 7-10 days less. To test this assumption, you need to repeat the ultrasound in a week to see the dynamics of the growth of the embryo.
- Pregnancy does not develop, the fetus died. The doctor will register the absence of movements and palpitations on an ultrasound scan.
- The child has genetic disorders. More research is needed to confirm this.
A deviation from the norm requires the close attention of a doctor.
The coccygeal-parietal size is one of those parameters that are primarily of interest to the doctor at the first screening, along with the thickness of the collar space and the length of the nasal bone. Based on the data obtained, conclusions are drawn about the successful development of pregnancy.