Gestational chamber: where the development of the embryo takes place during pregnancy
The gestational chamber is the place inside the uterus where, during pregnancy, the embryo develops after implantation of the fertilized egg. Generally, the gestational chamber can be seen during the first ultrasound, between the fourth and the fifth week of pregnancy. The gynecologist will take care to monitor it and compare it with the levels of the beta hCG hormone in order to accurately date the pregnancy and check that there are no problems with the fetus. Here is a video on the different ultrasound scans to do during pregnancy:
Gestational chamber: what it is and at what week of pregnancy it is possible to see it
The gestational chamber is a real "room", a place that takes shape around the embryo, also hosting the yolk sac in which the fetus will be wrapped up to the twelfth week of pregnancy.
You will be able to see your gestational chamber during the first ultrasound at your gynecologist, a "transvaginal control ultrasound that allows you to detect the presence of the gestational chamber, but only from the fourth or fifth week of gestation. Before that date, the chamber. gestational will not be visible because the values of the hCG hormone, the pregnancy hormone, will still be too low. During the fifth week of pregnancy, however, the value will be between 1000 and 2000 IU.
In the event that the gestational chamber does not appear during the first ultrasound, even if five weeks have passed since the "arrival of" the last menstrual period, you do not have to worry immediately: it may mean that you ovulated late and therefore the pregnancy goes post- dated. If, on the other hand, the value of your beta hCG should be higher than 1500-2000 IU and the gestational chamber is not yet visible during the ultrasound, an ectopic pregnancy could be in progress.
The control of hCG is very important, because if it does not grow, it could be an indication of a miscarriage: the pregnancy could be interrupted before the gestational sac has had time to form, and that is why it is not visible.
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Gestational chamber and yolk sac: what's the difference?
Often the gestational chamber and the yolk sac are confused, also because the gestational chamber is frequently called the "gestational sac". In reality, these are two very different things: the yolk sac, in fact, is the structure that surrounds and nourishes the embryo and which begins to form from the second week of pregnancy; it is in turn contained in the gestational chamber.
The shape of the yolk sac is very thin, similar to a ring, and continues to grow until the twelfth week inside the gestational chamber, until it disappears (deteriorating naturally) to make room for the placenta, which will in turn serve to protect and feeding the embryo in the following weeks of pregnancy.
Development of the gestational chamber week by week
The gestational chamber is constantly growing. It grows, in fact, at a speed of about 1mm per day, up to the eleventh week. It will be precisely the size of the gestational chamber that will allow us to accurately calculate the gestational period.
The calculation is done using the following formula: Gestational period = (Chamber diameter + 2.543) / 0.0702. The diameter of the gestational chamber is calculated in millimeters, while the gestational period is expressed in weeks. To simplify, you can refer to the table below:
gestational sac gestational period gestational sac gestational period Diameter (mm) (weeks) Diameter (mm) (weeks)
Empty gestational chamber and miscarriage
During the first ultrasound, it may also turn out that the gestational chamber is "empty", that is, there is no embryo inside it. If the embryo is missing (despite the fact that the gestational chamber produces amniotic fluid and has the right size in relation to the week of pregnancy in progress) means that the pregnancy cannot continue because a spontaneous abortion has occurred.
Spontaneous abortion can occur due to a chromosomal abnormality that did not allow the cells to transform into an embryo inside the gestational chamber.It is a kind of natural selection: the chromosomal anomaly immediately interrupts the pregnancy by itself in the first trimester.
The empty gestational chamber cannot be detected before the sixth week, because until then the embryo may simply not be visible yet. To be sure that a miscarriage has occurred, you will have to wait for at least the seventh week of pregnancy. the embryo will not be visible in the uterus during the ultrasound and it will miss the heartbeat, it will mean that unfortunately the abortion has occurred.
If the embryo has not formed and the pregnancy will be forced to interrupt, do not despair: there will be no consequences or complications and, when you feel ready again, you can try a new pregnancy. Just in case, following the discovery of the empty gestational chamber, you have undergone a uterine revision, it will be necessary to wait for the second menstrual cycle before attempting a new conception. miscarriage.
Irregularities of the management room: what are the consequences?
As we have seen, the gestational sac should grow in parallel with the passing of the weeks of pregnancy. If, however, the ultrasound shows a lower than expected growth, the reasons could be different: a small gestational sac could be due to an irregular cycle or an abnormal conformation of the uterus. Fortunately, only in very rare cases could a small gestational chamber prevent the development of the fetus, putting the pregnancy itself at risk.
Even if the gestational sac has a different shape from the circular one, there may be irregularities in the development of the fetus: a lot depends on the type of anomaly that occurs and your gynecologist will advise you on how to proceed and monitor how the situation evolves.
For more information on the gestational chamber, you can consult online at this link a chapter related to the topic taken from MacGregor, S, Sabbagha, R, Glob. libr. women's med., (ISSN: 1756-2228) 2008; DOI 10.3843 / GLOWM.10206, source of the table reported in our article.
