Search results
Results from the WOW.Com Content Network
Biologically, pregnancy starts at implantation of the fertilized egg. Human pregnancy can be divided into three trimesters, each approximately three months long: the first, second, and third trimester. The first trimester is from the last menstrual period through the 13th week, the second trimester is 14th–28/29th week, and the third ...
A typical precocial mammal has a gestation period almost four times longer than a typical altricial mammal of the same body size. [20] Precocial mammal species generally have greater adult body weights than altricial mammals as precocial mammals have markedly longer gestation periods than altricial mammals. [21]
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 ...
A newborn foal A foal will be able to run alongside of its dam within a few hours of birth.. Foals are born after a gestation period of approximately 11 months. [1] Birth takes place quickly, consistent with the status of a horse as a prey animal, and more often at night than during the day.
The duration of this period varies between species. For most species, the amount a fetus grows before birth determines the length of the gestation period. Smaller species normally have a shorter gestation period than larger animals. [2] For example, a cat's gestation normally takes 58–65 days while an elephant's takes nearly 2 years (21 ...
The first ten weeks of gestational age is the period of embryogenesis and together with the first three weeks of prenatal development make up the first trimester of pregnancy. From the 10th week of gestation (8th week of development), the developing embryo is called a fetus.
Distribution of gestational age at childbirth among singleton live births, given both when gestational age is estimated by first trimester ultrasound and directly by last menstrual period. [38] Roughly 80% of births occur between 37 and 41 weeks of gestational age.
Hippomanes first appears in pregnant horses and zebras ca. 85 days from conception, earlier there being small white flecks of tissue debris instead. [1] The changes in hippomanes color correspond to changes in color of allantoic fluid. [1] They are often surrounded by shed cells.