Fetal Development Stage In The Uterus

Human embryos who were aged around 1-24 days, attached to the uterus (womb) mother, like as 'leeches' stuck to the skin. Similarly to 'leech' who obtained the blood of its host, the human embryo is also obtained from the mother's blood during pregnancy. When comparing with the freshwater leech embryos at an early stage embryo, Professor Moore, a professor Emeritus of the University of Toronto, Canada, anatomy and embryology expert, found that a lot of similarities in both. He concluded that the embryo during this stage has an appearance very similar to the leech. At this stage, the embryo get food by sucking the blood of his mother, just like leeches. The embryo during this stage "hang" in the uterus (womb) of his mother. 

Professor Moore says we found the outside appearance of the embryo during this stage as the appearance of a blood clot, a large number of blood-forming embryos. Also during this stage, the blood in the embryo does not circulate until the age of embryos reaching the end of week three. So the embryo at this stage is similar to a blood clot.
Here is a simple table stages of fetal development per week.

Week #	Growth
1	Rapidly moving spermatozoa from the vagina to the uterus, and then into the fallopian tubes so that fertilization occurs.
2	estimated size of 0.1-0.2 mm embryo
3	In this week, the forerunner of the vascular system and the nervous system begin to form. In fact, in the last days when the forerunner of the fetal heart begins to form, the embryo has reached the size of 1.5-2.5 mm. Overall, in this week has been found the genetic material, including hair color, eye shape, and the intelligence of the baby.
4	Heart began to throb and circulatory system is performing its function, though still in its early stages is very simple. Placenta was also formed at this week.
5	The digestive system is perfectly characterized by increasingly real distinction between the forerunner of the large intestine and appendix. Even the forerunner of the kidneys and the liver was already formed.
6	Currently embryo estimated size of about 7-9 mm.
7	This week also begins the process of ossification body. While the boundaries between the forerunner curved vertebrae and ribs, just appear as elongated grooves. So also in the shoulder joint, hip, and knee began to appear.
8	Although still weak, the beginning of a whole body frame has been completed in this week. All the organs of the body also starts to work, though not perfect. This frail body began to move erratically, which when added an average of 60 times in an hour movement.
9	When the male gender, in this age can be clearly ascertained. While female are still occasionally dubious.
10	Began functioning of the nervous system, the fetus is able to do reflex. Foot is able to perform kicking motion.
11	The fetus has now been able to change its position by rotating, elongated, curled, or even somersault often painful sensation while providing happiness.
12	This week the skeletal system in the body has a central bone formation / bone ossification at most.
13-27	Fetal length (from crown to sacrum / buttocks) is estimated to be 65-78 mm with a weight of approximately 20 grams. External genitalia are also growing more real, to more easily distinguish gender. Pregnancy increasingly visible, for the convenience of the mother and the fetus, so it is recommended to start wearing maternity clothes. At this age the fetus produces alfafetoprotein, a protein that is only found in the blood of pregnant women. When excessive levels of this protein could be a sign of serious problems in the fetus, such as spina bifida, a congenital disorder that is associated with the spinal cord. In contrast, low levels of alfafetoprotein associated with Down syndrome. Starting at age 18 weeks, the interactive relationship between the mother and the fetus increasingly interwoven. Not surprisingly, every time the mother happy, sad, hungry or feel anything else, the fetus was feeling the same thing. At week 22, the estimated weight of 400-500 grams and reaches a length of about 19 cm, the mother is increasingly able to adapt to pregnancy. Fears of miscarriage has also been dashed. At age 26 weeks, birth weight is expected to reach nearly 850 grams, with the length of the buttocks and the top of the head about 23 cm. The heartbeat is clearly audible, normally 120-160 beats per minute. Abnormal heart rate should be observed because it is quite possible there is a symptom of a serious complaint.
28-40	At the age of 37 weeks, with a length of 47 cm and a weight of 2950 grams, at this age babies born is said to be ready, because the whole function of his organs could be to work alone. Usually the baby's head into the birth canal, the position ready for birth. Although a small portion of the breech position. At age 40 weeks, the length in the range of 45-55 cm and weighs about 3300 grams. Months really enough and ready to be born. If male, testicles descend into the scrotum, while in female, the labia majora (outer genital lips) are well developed and covers the labia minora (inner genital lips).