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the part of the fetus that lies closest to or has entered the true pelvis. Cephalic presentations are vertex, brow, face, and chin. Breech presentations include frank breech, complete breech, incomplete breech, and single or double footling breech. Shoulder presentations are rare and require cesarean section or turning before vaginal birth. Compound presentation involves the entry of more than one part in the true pelvis, most commonly a hand next to the head. See also fetal attitude, fetal lie, fetal position.
of or pertaining to a fetus or to the period of its development.
age of the fetus; this may be determined by its crown to rump length, and various other surface features such as hair follicles and eyelids.
fetal alcohol syndrome
in humans and laboratory animals; in laboratory animals manifested by small head and nose, narrow forehead, short palpebral fissures, long thin upper lip.
the circulation of blood through the body of the fetus and to and from the placenta through the umbilical cord. Oxygenated blood from the placenta is carried to the fetus by the umbilical vein. The blood from the fetus is returned to the placenta by two umbilical arteries. Oxygenation of the fetal blood and disposal of its waste products is carried on through the placenta. When the lungs begin to function at birth some of the fetal vessels, such as the ductus arteriosus, and the fetal passages, such as the foramen ovale, begin to fall into disuse. This is a gradual process of fibrosis that takes place in the period after birth.
too much fetal tissue in the uterus. May cause fetal retardation in some; also papyraceous fetus. Thought to cause some of the minor congenital deformities, e.g. carpal flexion in calves, facial distortion in foals.
results in resorption, mummification or discharge to the exterior.
fetal death ratio
see fetal death ratio.
crown to rump (tail head) length; varies with species; useful as a guide to pregnancy duration.
disease of the fetus in utero.
in cattle may be due to inherited defect of lymph nodes and lymphatic drainage.
dystocia caused by some characteristic of the fetus, e.g. size, monstrosity, dropsy.
fetal early death
see early embryonic mortality.
a device consisting of a breech bar that fits across the back of the cow's thighs below the vulva, with a 6 ft long rod with a ratchet running its length. A small tractor is levered along the ratchet and exerts traction on the calf via obstetric chains fitted to its feet. Has the advantages of a block and tackle but with the mobility of being fixed to the cow.
the amniotic and allantoic fluids.
due to prolonged gestation, although all prolonged gestations are not giants. Inherited in Holstein cows.
focal or diffuse lesions in the fetal liver caused by bacteria or viruses, e.g. Tyzzer's disease, equine herpesvirus 1.
sterile necrosis and dissolution of the fetus. May be ejected in this form or go on to mummification.
presentation of the fetal parts in inappropriate positions for the easiest passage through the cervix, e.g. retention of the head, breech presentation.
fetal maternal rotation
alteration of the longitudinal relationship of the fetus to the dam effected per vaginam by manipulation with the hand or an obstetric crutch, or externally by casting the dam and rolling her from side to side while the fetus is held in position via a hand in the vagina.
the membranes which protect the embryo and provide for its nutrition, respiration and excretion; the yolk sac (umbilical vesicle), allantois, amnion, chorion, decidua and placenta. See also extraembryonic membranes, placenta.
fetal membrane expulsion
occurs usually at the birth or less commonly within 12 hours; expulsion is by means of separation of the uterine attachment and contraction and involution of the uterine wall.
fetal membrane retention
see retained placenta.
fetal membrane slip
the sensation of a thread or edge of tissue slipping through the fingers when the amniotic vesicle in an early pregnant bovine uterus is grasped between the thumb and forefinger; the best indicator in a manual check for pregnancy until the time when cotyledons can be palpated.
fetal movements during pregnancy.
position of the fetus within the dam, described in terms of the dorsum of the fetus and the sector of the circumference of the dam's pelvis, e.g. dorsosacral, dorsoventral.
relationship of the movable extremities or appendages of the fetus to each other and the rest of the fetus, e.g. flexed neck.
a method of correcting uterine torsion in cows; the fetus is reached manually via the vagina and the fetus rotated around its long axis using a firm grasp on the upper part of a limb as a handle; the uterus, clinging to the fetus, rotates with it, undoing the torsion. Requires a fresh parturition, a slim but strong forearm and a nice appreciation of the physical law of torque.
early death of the embryo during the fetal period with lysis and complete resorption of all of the products of the conception. The dam resumes normal estral cyclicity after a period of anestrus while there is maternal recognition of the pregnancy. See also early embryonic mortality.
fetal sex diagnosis
the karyotype of the fetus is determined from fetal cells collected from the amniotic fluid by amniocentesis.