Antenatal Care – Obstetrics | Lecturio
Screening is on guard for the health of a pregnant woman!
Screening is a relatively new and unfamiliar procedure, and ignorance and attitude towards it can vary, from sharply positive to categorically negative. However, experts say that the screening test is an absolutely safe and completely painless method of examining pregnant women, which can provide complete necessary information about the fetus and its development at the moment.
It is not rational not to take into account the information obtained as a result of such a procedure, because with such awareness, parents can prepare in advance for any unexpected turns related to the health of the unborn child.
If we translate the name of the procedure, then literally it will be sifting , that is, healthy pregnant women are eliminated from those who have possible problems and complications during childbirth or after them.
Thanks to this procedure, you can calculate the most accurate probability of Down's syndrome, calculate possible spontaneous miscarriages, developmental defects, and so on. On the other hand, a woman's ignorance during pregnancy can bring unforeseen difficulties on her that she may not be ready for.
So there is no need to prove the benefits of screening. The examination during the first trimester is called the first or early and is carried out from 11 to 13 weeks after consultation with a doctor.
Timing of the second screening
The timing of the second screening during pregnancy (it is also called a triple test, the name comes from the amount of hormones that is tested) experts determine from the fourteenth to the twentieth week from the date of the last menstruation. The most favorable period for the test is the period from the sixteenth to the eighteenth week.
This is due to the fact that just at this period a pregnant woman has the maximum amount of hormones in her body, and the results of screening in this state of affairs will be as close as possible to the real state of affairs.
The triple test comprehensively includes the determination of certain hormone markers in the blood of a pregnant woman (AFP (alpha-fetoprotein), free estriol, and b-hCG) and ultrasound or ultrasound. It is carried out for all women in order to confirm an early examination orrefutation of the first data. Or a second screening is performed for indications that are acute.
Indications for research
Indications for research are the same as the first screening and they are quite logical.
This screening is prescribed in the following cases:
- if the future parents of the child have a blood relationship;
- the expectant mother has suffered an acute bacterial or viral disease;
- if a woman suffers from genetically transmitted diseases: oncological pathology, diabetes mellitus, diseases of the musculoskeletal system;
- even if one of the parents in the family has a genetic disorder called chromosomal;
- if the expectant mother has already had a premature birth or miscarriage;
- if a pregnant woman has already had a child with developmental abnormalities;
- if the pregnant woman had a history of fetal death before delivery;
- if in a pregnant woman, an abnormality in the development of the fetus was revealed during the initial ultrasound scan at the fourteenth week of pregnancy.
Another reason for research is the development of an acute infectious disease in the period from the fourteenth to the twentieth week, or if a tumor was found in a pregnant woman later than the fourteenth week.
In cases of acute infectious disease and tumor, a woman should be referred to a geneticist to address the need for a full perinatal second trimester study.
Metrics for Grading
During the second screening examination, the following indicators are assessed: the volume of the head, abdomen, chest, the length of the bones of the same name on both sides. During the second examination, it is possible to draw a conclusion - whether the gestational age, the size of the fetus and the proportionality of its development correspond to.
The cerebellum and ventricles of the brain, the face and profile of the face are assessed, including the orbits and nasolabial triangle, spine, bladder and kidneys, intestines and stomach, ventricles and atria of the heart, as well as the places of large vessels departing from it. By the way, during the second screening procedure, you can find out if there are organ developmental abnormalities and how the cardiovascular system develops.
At the same time, this examination also shows maternal provisional, or temporary organs. With its help, the thickness and location of the placenta, its degree of maturity and structure are assessed; the number of vessels in the umbilical cord and amniotic fluid; condition of the appendages, cervix and walls of the uterus. And already taking all these indications, we can conclude whether there are currently any deficiencies in the development of the fetus, or not.
Considering all this information and all the risks that may arise, as well as knowing that during a second pregnancy, childbirth may be earlier than the first, screening is a good waythe ability to learn about all possible threats in advance.
Examination of hormone levels
So, for example, as mentioned above, biochemical screening determines hormone markers, including AFP, a protein that is present in the blood of an unborn child at a fairly early stage of embryonic development. It is produced in the liver and gastrointestinal tract of the fetus, and its function is to protect the fetus from the mother's immune system.
If an increase in the AFP level is noticed, this indicates the probable existence of either Meckel's syndrome or anencephaly - a malformation of the fetal neural tube, or esophageal artesia, or umbilical hernia, as well as possible nonunion of the anterior abdominal wall or fetal liver necrosis.
But a low level of the same AFP makes it possible to assume the presence of Down syndrome, Edwards syndrome, incorrect calculation of the gestational age or fetal death.
Free estriol is produced by the fetal liver, although in the beginning, nevertheless, the placenta, and if development is taking place normal, its level is constantly growing.
An increase in its level can be the cause of the following situations: multiple pregnancy, large fetus, kidney or liver disease in a pregnant woman. But a decrease in this hormone may be evidence of intrauterine infection, hypoplasia of the adrenal glands of the fetus, the threat of premature birth, fetal anencephaly, Down's syndrome or fetoplacental insufficiency.
Screening and second birth
During the first birth, everything goes much more difficult and longer, and, with a normal pregnancy, they rarely come before 38 weeks. But with the timing of labor in the second pregnancy, things are different.
A second pregnancy can end in childbirth, which will begin rapidly and a period of 38 weeks of pregnancy for a second birth is a normal thing. Screening helps to understand whether the mother and the baby, whom she carries under her heart, are ready for a rapid unexpected birth. Well, if the second birth occurs at 39 weeks, then we can assume that you have successfully delivered the baby and he is completely ready for birth.
Screening or not - it is up to the future parents to decide, taking responsibility for all possible risks. The doctor's task is to explain to the pregnant woman the feasibility of conducting the analysis and properly prepare the expectant mother for it.