Ads
related to: 21 weeks pregnant bump
Search results
Results From The WOW.Com Content Network
Gestational age: 4 weeks and 0 days until 4 weeks and 6 days old. 29–35 days from last menstruation. Embryonic age: Week nr 3. 2 weeks old. 15–21 days from fertilization. A notochord forms in the center of the embryonic disk. (day 16 of fertilization. [1]) Gastrulation commences. (day 16 of fertilization. [1])
A woman pregnant for the first time (nulliparous) typically feels fetal movements at about 21 weeks, whereas a woman who has given birth before will typically feel movements by 20 weeks. [13] By the end of the fifth month, the fetus is about 20 cm (8 in) long.
Based on the size and growth of the fetus, her doctors estimated the pregnancy to be 23 weeks along, nearly the end of the second trimester, according to the report.
In human pregnancy, prenatal development is also called antenatal development. The development of the human embryo follows fertilization, and continues as fetal development. By the end of the tenth week of gestational age, the embryo has acquired its basic form and is referred to as a fetus. The next period is that of fetal development where ...
During continued fetal development, the early body systems, and structures that were established in the embryonic stage continue to develop. Sex organs begin to appear during the third month of gestation. The fetus continues to grow in both weight and length, although the majority of the physical growth occurs in the last weeks of pregnancy.
Human embryonic development covers the first eight weeks of development, which have 23 stages, called Carnegie stages. At the beginning of the ninth week, the embryo is termed a fetus (spelled "foetus" in British English). In comparison to the embryo, the fetus has more recognizable external features and a more complete set of developing organs.