Pregnancy is a physiological process of development of fetus out of a fertilized cell. In a body of a pregnant woman many complicated changes occur which create favorable conditions for intrauterine development of a fetus and the organs of a women are prepared to the act of delivery and breast feeding of the newborn. Pregnancy occurs in the result of fertilization, i.e. male and female cell fusion. Male reproductive cells are spermatozoids. The latter develop in male glands- testicles and consist of head, neck and long tail which helps the spermatozoid move. During sexual intercourse the spermatozoids contained in ejaculate (seminal fluid) get into woman`s vagina. Under favorable conditions the spermatozoids pass the whole way from vagina through neck and body of the womb and uterine tube within 12 hours. Besides active movement of spermatozoids, their advancement through the uterine tube is also promoted by contraction of muscular layer of the tube. The contraction of the muscular layer occurs during sexual intercourse and runs in a form of waves from the womb to the end of the uterine tube. The spermatozoids meet the ovum in the uterine tube. One of the spermatozoids perforates the membrane of the ovum and merges with it. After merging with the spermatozoid the ovum starts to grow and develop. At the same time it moves along the tube towards the womb. The motion of the ovum through the tube happens due to contraction of the muscular layer of the uterine tube and twinkling movements of villi located on its mucous membrane. During its motion, the fertilized ovum is nourished on the substances which are contained in itself. Only when the fertilized ovum penetrates into womb and gets fastened to one of its walls, the ovum starts getting nourished at the expense of the maternal organism. By the third month of pregnancy the fetus starts getting nourishment from the mother through the vessels of the navel string. The navel string is terminated at the placenta which is closely connected with the internal wall of the womb. Through blood vessels of placenta and navel string the nutrients, water and oxygen get from mother`s body to the fetus. The fetus and the womb gradually increase in size.
The fetus developing in the womb is surrounded by special membranes in a form of a sack filled with amniotic fluid. Usually by the end of pregnancy the fetus in the womb assumes a lengthwise position with his head down towards the small pelvis; during delivery the head of the baby is the first to go through the pelvis. In rare cases the baby could be positioned with his buttocks down.
This position poses a serious threat for baby`s health during delivery; in such cases the mothers-to- be are recommended to visit maternity welfare center regularly and keep carefully to all doctor`s directions. So called transverse lie (shoulder presentation) of the fetus is possible as well, though rare. It is considered a difficult case and a woman is unable to give birth to a fetus in this position without special medical assistance (e.g. cesarean section).Women react to the news about pregnancy in different ways. Some of them accept the news enthusiastically, others fall into depression. The body of a pregnant woman has a hard time getting adjusted to ongoing physiological changes associated with pregnancy, that is why you should prepare yourself physically and emotionally in advance. Nourishing food is very important in this period both for you and your baby. Do not underestimate the meaning of physical exercises in this period – it will help to keep your body in shape and facilitate the delivery. Even the mood of the mother may influence the development of the fetus. During pregnancy women should avoid contacts with chemicals, stay away from high temperature and sources of radiation. Non-observation of these directions may lead to grieve consequences.To any woman pregnancy is one of the happiest and most important life periods, so follow your doctor`s advices carefully not to complicate your condition in this fine period of your life.
