From 12 to 40 weeks begins fetal period of development of the future baby. At this time, all systems of organs are not yet functionally developed. Week 13 is the period of local motor reactions of the fetus. Nervous, respiratory, endocrine, bone systems of the fetus continue to form actively. The features of your future baby become more expressive. The 13th week of pregnancy is the initial period of the first emotional reactions of the future baby.
Fetal development at 12-13 weeks
To assess the development and diagnosis of fetal pathology, fetometry of the fetus is performed at 12 or 13 weeks.
Parameters of fetometry and their norm for the fetus at the 13th week of pregnancy:
- biparietal fetal size - 24 mm;
- length of the thigh - 12 mm;
- chest circumference - 24 mm.
At 13 weeks, the embryo has a weight of 31 grams, a height of 10 cm.
TVP at 13 weeks
The thickness of the collar or TVP is a parameter that doctors pay attention to during ultrasound screening at the 13th week of pregnancy. The thickness of the collar space is the accumulation of fluid on the back surface of the fetal neck. The definition of this parameter is important for the diagnosis of genetic abnormalities of fetal development, in particular in the definition of Down syndrome, Edwards, Patau.
TVP at 13 weeks is the norm
The normal physiological value of the thickness of the collar space is 2.8 mm at week 13. A small amount of liquid is characteristic of all babies. The increase in the thickness of the collar space of more than 3 mm indicates the possible presence of Down's syndrome in a future baby. To confirm the diagnosis, it is necessary to conduct additional invasive examinations, which can be dangerous for the baby. The risk of developing this pathology during the first pregnancy after 35 years is especially increased.
Remember that the diagnosis of increased thickness of the collar space does not mean a 100% presence of genetic pathology , but only allows to determine the risk group among pregnant women.