Fetal growth is an important criterion for assessing its development. Together with other diagnostic parameters, the growth of the fetus for weeks allows the doctor to assess how the pregnancy as a whole proceeds.
By the growth of the fetus for weeks of pregnancy, you can determine whether any pathogenic factors influence the development of the future child. Fetal growth retardation may indicate lagging behind in total development or fading pregnancy .
Fetal growth is calculated when a woman undergoes ultrasound, starting from the middle of the first trimester of pregnancy. Until this time, the growth of the fetus is difficult to measure due to the negligible size of the embryo.
Fetal growth is measured only until 12-13 weeks of gestation. In this case, the growth of the baby is reflected in the conclusion of an ultrasound called a coccyx-parietal size or KTP , which is the length of the child's body from the coccyx to the temechka (the length of the legs is not taken into account here).
At later stages of pregnancy, the trunk and legs of the fetus are bent or in a different position. Therefore, the length of the fetus is very difficult to measure. And instead, other parameters are measured: the size of the limbs, the circumference of the abdomen and the head, and then compare the results with the normalized values.
Calculation of fetal growth
To calculate the growth of the fetus, you can use special formulas.
P = 3.75 x H = 0.88 or P = 10 x P-14 ,
Where
- P is the growth of the fetus (cm),
- H - length of the fetal leg (length of the tibia plus the length of the femur, cm),
- P is the length of the humerus of the fetus (cm).
The normalized value of fetal growth for each week of pregnancy can be learned using special tables. But it should be remembered that each child develops individually and the data, which are given in the tables, represent the average growth rates for weeks.
If, according to the results of ultrasound, it is determined that the baby has a growth above or below the average, this is not a cause for concern.
Fetal Growth Chart by Week of Pregnancy
| Week of pregnancy | Fetal growth, mm | Week of pregnancy | Fetal growth, mm |
|---|---|---|---|
| 14 | 8-10 | 28 | 36-38 |
| 15 | 10-11 | 29 | 38-40 |
| 16 | 14-17 | thirty | 40-42 |
| 17th | 21.5 | 31 | 40-43 |
| 18 | 22.5 | 32 | 43-44 |
| 19 | 22-23.5 | 33 | 44-45 |
| 20 | 23-25.4 | 34 | 45-46 |
| 21 | 24-26 | 35 | 45-47 |
| 22 | 25-26.5 | 36 | 48-50 |
| 23 | 26-27 | 37 | 50-53 |
| 24 | 27-27.5 | 38 | 53-54 |
| 25 | 28 | 39 | 53-56 |
| 26th | thirty | 40 | 53-56 |
| 27th | 32-36 |