The growing conceptus of the domestic cat.
The feline conceptus is similar to larger mammals rather than to rodents in the amounts of fetal fluids and the contribution of the fetus to the total volume of the conceptus. When growth rates of several mammals are compared as Gompertzian functions, the feline fetus is more similar to that of the guinea pig or beagle than that of the mouse, rat, man, sheep or cow. The feline Gompertzian growth starts at about the 6th day of gestation. The weight of the fetus, +/- 10%, as a function of gestational age starting on day 28 is: Weight in grams = 2.6477 X 10(-10) exp (see article) when t = gestational age of 28 days or more. The feline weight to crown-rump relationship can most easily be expressed as a power function where: Crown-rump length in cm = 2.69 (weight in grams) 0.3508; with an error term of +/- 5%. The relationship of three variables gestational age, fetal weight, and fetal crown-rump length can also be expressed mathematically: Gestational age in days = 15.335 + 3.9805 (crown-rump length in cm) -0.0675 (weight in grams) Equations for crown-rump length or weight were calculated, but the inaccuracy of these expressions is too great to allow practical use.
D000818:Animals; D001826:Body Fluids / Q000032:analysis; D001835:Body Weight; D002415:Cats / Q000196:embryology*; D005260:Female; D005333:Fetus; D006128:Growth; D010920:Placenta / Q000502:physiology; D011247:Pregnancy; D013223:Statistics as Topic