The third screening is a critical examination, the final stage of prenatal diagnosis. This set of procedures is designed to control the development of the fetus, as well as confirm existing ones or discover pathologies that could not be detected earlier.
When does the third screening?
The third screening recommended to be done between the 32nd and 34th weeks of gestation. At this time, the results of the Pregnancy Ultrasound will be the most accurate, contain more critical information about the health of the baby, the state of embryonic organs in the light of approaching births.
What happens in the womb at this time?
- Increase the size of the body of the baby.
- His internal organs grow (lungs, brain, etc.).
- The skin becomes denser; a layer of subcutaneous fat is formed.
- The fetus is specially located in the womb.
- The number of amniotic fluid increases.
All these processes help to make the screening of the 3rd trimester more informative and valuable, as they allow you to see more than before.
Sometimes a doctor can prescribe some tests before the beginning of the 32nd week. For example, if suspicion of hypoxia or a delay in fetal development of the fetus, dopplerometry (ultrasound examination of blood vessels) is carried out at week 28. With any specific indication, the doctor may insist on the implementation of additional ultrasound, CTG, and other procedures, regardless of the timing of their planned application.
In some cases, tests may be needed immediately before childbirth. Therefore, it is impossible to say precisely what week three screening is done. This is not a universal date, but it depends on the individual needs of each patient.
Indications for screening for the 3rd trimester
Though ultrasound is mandatory in such cases. But due to various factors (for example, the unfavorable ecological situation in the city etc.), experts insist on carrying out an integrated screening for all pregnant women. There are some different conditions under which it is necessary to go through the third screening of the expectant mother.
Detection of defects in prenatal development of the fetus during research in the first-second trimesters;
- Mother-borne viral infections;
- Forced or accidental reception of drugs dangerous for pregnancy;
- The presence of family ties with parents;
- Late childbearing age (future mother over 35);
- Cases of previous miscarriage, birth of a dead fetus;
- Hereditary diseases and abnormalities in the family history;
- Bad habits (taking drugs, alcohol);
- Intensive mental or physical work, work in lousy production.
Three screening: goals and objectives of the survey
The purpose of Pregnancy Ultrasound at any stage of pregnancy is to monitor its course, to mark and prevent complications in time, to determine how the fetus is developing, and to detect pathologies of its development. Based on the results of the third-trimester studies, the doctor assesses the readiness of the mother's organism for childbirth, suggests whether pregnancy can be resolved naturally or if a surgical procedure is necessary.