The fourth week of pregnancy - the baby takes shape
fourth week of pregnancy - a new stage in the formation of the embryo.Prior to that, the cells of the embryo just shared, and the fourth week, they begin to acquire various properties characteristic of different tissues and organs.This is a very important stage of development - the future begins laying authorities.During this period, the fetus should not have any adverse impacts, so the woman should give up smoking, drinking and drugs.
metabolic processes in a woman's body in the fourth week of pregnancy
Under the influence of hormonal changes that occur in a woman's body a week after the introduction of a fertilized egg in the uterine lining, rebuilt all the metabolic processes in the female body.This may appear signs of pregnancy such as nausea Nausea - there may be problems with the nervous system , drowsiness, increased appetite, and increase breast tenderness.
is increasing the basal metabolic rate and oxygen consumption, nitrogen accumulates in the body, its stock is to build the proteins that build the cells of the fetus.Activates carbohydrate metabolism, are amplified supply of carbohydrates as glycogen, which is deposited as a reserve in the liver and muscles.Alter lipid metabolism: blood of pregnant increases the amount of neutral fat, fatty acids, cholesterol and other lipids that are spent on the formation of fetal tissue.
During pregnancy a woman's body comes as a delay of many inorganic substances.There is increased uptake of phosphorus, necessary for the development of the nervous system and the skeleton of the fetus.There is an accumulation of iron, the bulk of which goes to cover the needs of the pregnant woman (in her body there is an active development of red blood cells containing hemoglobin Hemoglobin: worse - low or high? , which includes hardware).Another part of the iron is spent on the construction of the fetus and placenta.Accumulate in the body of the pregnant woman, and minerals such as potassium, sodium, magnesium, chlorine, cobalt, copper and so on.These substances are also transferred to the fetus and ensure the normal course of its metabolic processes and growth.The accumulation of inorganic matter affects the water metabolism in women: a delay of water, there is a tendency to edema.
needs of pregnant women in vitamins (A, B1, D, E, K, PP, and especially c) increases due to the need to supply themfetus and maintain metabolic rate Metabolism: The basis of life of all living .
As a developing fetus
Since the beginning of the fourth week of pregnancy begins a new period in the development of the human embryo.Before that he shared a cell (during gastrulation), they are now beginning to be separated to acquire new properties, ie, a period of segmentation or somitic period.This is separated from the body of the embryo and extraembryonic parts of the closure of the neural plate into the neural tube, which is segmented, and gives rise to the beginnings of spinal cord cells.
germ cells are divided into ectoderm (of her shell formed fetus and placenta), endoderm (the body of the fetus) and the mesoderm, which is located between the ecto- and endoderm.During the period of the segmentation sections mesoderm adjacent to the neural tube, the notochord and begin to grow thicker, and then divided into segments, that is, on portions separated by constrictions.This primary segments or somites, the number of which can be seen on the age of the fetus.On average, each day 2-3 somites formed, so that by the end of segmentation (this is the first 35 days of pregnancy) there are more pairs 43-44.Each
somite in turn divided into three portions.One (lower) gives rise sclerotome cells which surround the neural tube and notochord, forming first cartilage and then bone skeleton.From another part of the somites (top) there is dermatitis or skin plate.The rest of the somites, which lies between sclerotome and dermatotom goes to education bud skeletal muscles - myotome.
Thus, during the fourth week of pregnancy there is the main tab body tissues of the fetus.
What tests can be done to detect pregnancy in the fourth week
to detect pregnancy in the fourth week, you can conduct the following studies:
- home pregnancy test - it is found in the urine of women pregnancy hormone - human chorionic gonadotropin (HCG), which begins to produce the outer shell of the embryo after its introduction into the uterus, ie the second week of pregnancy;for the fourth week in a pregnant woman's blood enough HCG for a home pregnancy test;
- determination of hCG in the blood of female consultation - a more accurate and reliable research;
- determining the size of the uterus (it has increased in size) with a pelvic exam;
- ultrasound - the most reliable method that allows not only to establish the fact of pregnancy, but also to determine the place of implantation of the ovum, ie exclude ectopic pregnancy Ectopic pregnancy - Fatal dangerous .