Search results
Results from the WOW.Com Content Network
A marsupial has a short gestation period, typically shorter than placental. For more information on how these estimates were ascertained, see Wikipedia's articles on gestational age. The gestation figures given here are shown in days. They represent average values and should only be considered as approximations.
Gestational age: 30 weeks old. Embryonic age: Week nr 29. 28 weeks old. The fetus reaches a length of about 38–43 cm (15–17 in). The fetus weighs about 1.5 kg (3 lb 5 oz). The amount of body fat rapidly increases. Rhythmic breathing movements occur, but lungs are not fully mature. Thalamic brain connections, which mediate sensory input, form.
The first trimester is from the last menstrual period through the 13th week, the second trimester is 14th–28/29th week, and the third trimester is 29/30th–42nd week. [6] Birth normally occurs at a gestational age of about 40 weeks, though it is common for births to occur from 37 to 42 weeks. [ 6 ]
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 many organs become fully developed. This fetal period is described both topically (by organ) and chronologically (by time) with major occurrences being listed by gestational age.
For example, if there is a gestational age based on the beginning of the last menstrual period of 9.0 weeks, and a first-trimester obstetric ultrasonography gives an estimated gestational age of 10.0 weeks (with a 2 SD variability of ±8% of the estimate, thereby giving a variability of ±0.8 weeks), the difference of 1.0 weeks between the ...
There is no sharp limit of development, age, or weight at which a fetus automatically becomes viable. [21] According to data from 2003 to 2005, survival rates are 20–35% for babies born at 23 weeks of gestation (5 + 3 ⁄ 4 months); 50–70% at 24–25 weeks (6 – 6 + 1 ⁄ 4 months); and >90% at 26–27 weeks (6 + 1 ⁄ 2 – 6 + 3 ⁄ 4 ...
At 5 weeks, the embryo is a mass of cells with a developing neural tube (pre-spinal cord and brain). The forming fetus is no larger than a grain of rice.” Pregnancy tissue after an abortion at 5 ...
Until about the ninth week of gestational age, [4] the external genitalia of human males and females look the same, and follow a common development. This includes the development of a genital tubercle and a membrane dorsally to it, covering the developing urogenital opening , and the development of the labioscrotal fold .