You probably do not know about the pregnancy. Perhaps, however, this week you will notice a slight, smearing bleeding. This so-called "implantation bleeding" - it occurs when the fertilized egg is embedded in the wall of the uterus (a process that begins after about six days after fertilization). However, this bleeding is not at all.
As your child grows
What is happening now in your womb? A lot of everything. Your child now - a tiny ball of several hundred cells, the number of which is growing rapidly. Once a cluster of cells (blastocyst) takes its place in the uterus, it becomes part of the placenta, and begins production of the pregnancy hormone hCG (human chorionic gonadotropin). This hormone gives ovaries signal, after which they are no longer to mature egg; it also causes an increase in estrogen
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and progesterone (they prevent delamination of the inner lining of the uterus - along with her young tenant - and stimulate the growth of the placenta). HCG - the same hormone that responds to a home pregnancy test. By the third week of pregnancy hCG, as a rule, is so high that the test may show a positive result. (If the test result is negative, try to do another test in a few days.)
Meanwhile cluster around cells in a cavity, which then becomes the amniotic sac, amniotic fluid begins to accumulate. This liquid is the habitat of your child in the coming weeks and months. Now the blastocyst is receiving oxygen and nutrients (as well as displays wastes) through a primitive circulation system consisting of microscopic channels connecting developing baby with the blood vessels in the wall of the uterus. Placenta is not developed enough to take on this function.
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Already in the third week may receive the following early symptoms of pregnancy:
- Breast tenderness - many women experience shortly before its period but during pregnancy symptom usually more pronounced.
- Fatigue is not related to the level of activity - it may appear soon after you wake up. Increased levels of progesterone
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and many other changes in the body, forcing many expectant mother feel like they run a marathon.
- Frequent urge to urinate. Now this is certainly not due to the pressure of the uterus on the bladder
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And with changes in hormonal levels.
- Aggravation of smell presumably a side effect of raising the level of estrogen. Scents that were previously virtually indistinguishable or weak, can now cause a strong aversion or nausea.
- Aversion to certain foods, even to my earlier, is a very common early sign of pregnancy
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.
- Nausea or vomiting usually appear a few weeks later, but first some women experience this symptom on the third week.
What happens to the fetus in the third week of pregnancy
Pregnancy begins with conception, which occurs in the fallopian tube. A week after conception, the embryo is embedded in the mucous membrane of the uterus and begins to actively develop there. At the same time it begins to produce the pregnancy hormone - human chorionic gonadotropin (hCG). Initially, the amount of it slightly, but it is growing rapidly, doubling every two days.
At the very moment of conception, the egg begins to divide continuously. This so-called period of gastrulation. By the end of the second week of the embryo tissue is divided into ectoderm (from it formed the placenta and fetal membranes) and endoderm (the basis of the body of the fetus). In the third week begins the second phase of development of the embryo - formation of the middle germ layer and complex chord and neural tube. According to the midline of the body of the embryo, from its rear edge, the concentration of cells - the primitive streak, which grows forward, resulting in the primary bundle. From the primitive streak forms the middle piece of the embryo, which grows into the gap between the ecto- and endoderm. From the primary node in the third week of pregnancy grows cell cord - a head (chordal) process - the germ of the future back or chord. It is located under the ectoderm and the endoderm is closely related to.
Cells ectoderm adjacent to the notochord rudiment, beginning to grow tall and wide form the neural plate - a rudiment of the nervous system. With the laying of the middle germ layer at the end of the third week of the pregnancy period ends gastrulation and segmentation period begins when the cells are separated and begin to acquire various properties specific to different tissues.
Hormonal changes in women
The woman's body continues to increase the amount of pregnancy hormone - human chorionic gonadotropin (hCG). This hormone starts producing the outer shell of the embryo (chorion), after its introduction into the uterine cavity. This occurs at the end of the first week of pregnancy. Initially, the amount of HCG is insignificant and it is difficult to detect, but it is growing very rapidly, and the third week of pregnancy, hCG can be detected by a home pregnancy test.
The main objective of hCG - stimulation of the corpus luteum of the ovary of the female sex hormone progesterone. The corpus luteum is formed in the ovary in place bursting of the follicle, from which the mature egg. Functioning corpus luteum until the fourth month of pregnancy, when matured by this time the placenta takes over the function of providing hormonal pregnancy. Progesterone - a hormone that maintains pregnancy in its entirety, promoting fruit ripening and its retention in the uterus (progesterone inhibits the contraction of the muscles of the uterus). By the end of pregnancy there is a replacement for other female sex hormones - estrogens that promote the expulsion of the fetus from the uterus, ie leave.
How to detect pregnancy in the third week
In the third week, a woman still does not feel her pregnancy, unless she feels it on a purely visceral level. But there may appear signs of pregnancy such as nausea, drowsiness, increased appetite, and increase breast tenderness. During this period, pregnancy can be detected by a home pregnancy test, passing blood on the HCG or by viewing an obstetrician-gynecologist and ultrasound (US).
Since proliferation takes place in the uterus tissue, it increases in size. In the third week of pregnancy, it is quite possible to detect. In early pregnancy, the uterus is not beyond the pelvic bones, increasing its size may be determined by vaginal examination (it is carried out at the gynecological examination) or ultrasound.
Of course, the woman to consult an obstetrician-gynecologist would like the most to make sure that she is pregnant. Today, it is quite possible. In the third week of pregnancy, the body already generates a sufficient amount of hCG, so it can be detected by a home pregnancy test.
Home pregnancy tests are surfaces (strips, plates, etc.) impregnated with antibodies to hCG. The interaction of these antibodies with hCG reaction occurs as a result of which the surface of the dough changes occur. The test strips - it's pink and red stripes (basic and control), in some other tests displayed the inscription - "pregnant / not pregnant."
Positive pregnancy test should be the occasion to refer to the antenatal clinic and pregnancy is confirmed.
Galina Romanenko
Article Tags:
- first trimester of pregnancy
