fetal membranes

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fetal membranes

the structures that protect, support, and nourish the embryo and fetus, including the yolk sac, allantois, amnion, chorion, placenta, and umbilical cord.


of or pertaining to a fetus or to the period of its development.

fetal age
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.
fetal circulation
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.
fetal crowding
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.
fetal death
results in resorption, mummification or discharge to the exterior.
fetal death ratio
see fetal death ratio.
fetal dimensions
crown to rump (tail head) length; varies with species; useful as a guide to pregnancy duration.
fetal disease
disease of the fetus in utero.
fetal dropsy
in cattle may be due to inherited defect of lymph nodes and lymphatic drainage.
fetal dystocia
dystocia caused by some characteristic of the fetus, e.g. size, monstrosity, dropsy.
fetal early death
see early embryonic mortality.
fetal extractor
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.
Enlarge picture
Calving jack (fetal extractor) for use in a cow. By permission from Parkinson TJ, England GCW, Arthur GH, Arthur's Veterinary Reproduction and Obstetrics, Saunders, 2001
fetal fluids
the amniotic and allantoic fluids.
fetal giantism
due to prolonged gestation, although all prolonged gestations are not giants. Inherited in Holstein cows.
fetal hepatitis
focal or diffuse lesions in the fetal liver caused by bacteria or viruses, e.g. Tyzzer's disease, equine herpesvirus 1.
fetal maceration
sterile necrosis and dissolution of the fetus. May be ejected in this form or go on to mummification.
fetal malposition
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.
fetal membranes
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 mobility
fetal movements during pregnancy.
fetal mole
see mole.
fetal monstrosities
fetal position
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.
fetal posture
relationship of the movable extremities or appendages of the fetus to each other and the rest of the fetus, e.g. flexed neck.
fetal presentation
fetal rotation
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.
fetal resorption
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.
References in periodicals archive ?
It also disclosed that the antimicrobial effects of fetal membranes are significantly stronger on some certain bacteria.
At the same time there was leukocyte infiltration of basal and chorionic plate, intervillous space and fetal membranes, resulting in widespread and more severe pathological changes to the placenta.
The owner had attempted to remove retained fetal membranes after parturition.
Preterm premature rupture of membrane (PPROM) is defined as rupture of fetal membrane before onset of labor at less than 37 completed weeks of gestation.
Messersmith has created new materials that mimic mussel adhesive proteins for three medical applications: sealants for fetal membrane repair, self-setting antibacterial hydrogels, and polymers for cancer drug delivery and thermal destruction of cancer cells.
Inclusion criteria were a singleton live fetus, post-term pregnancy from 40 weeks and 1 day to 40 weeks and 9 days, intact fetal membranes, Bishop's score [less than or equal to] 5 and cephalic presentation.
Induction of pro-inflammatory cytokine gene expression and apoptosis in human chorion cells of fetal membranes by influenza virus infection: possible implications for maintenance and interruption of pregnancy during infection.
Studies have suggested that bacterial infections of the placenta and fetal membranes may play a major role in preterm birth.
The significance of the phenomenon is manifested by fetal and placental abnormalities that are associated with increased rates of pregnancy losses, particularly in the first 60 days of gestation (11, 17, 18, 19), and placental and fetal alterations that culminate in hydrops of the fetal membranes, late abortion, prolonged gestation, diminished signs of parturition, dystocia and birth of large calves with lower postnatal survival (5, 7, 8, 10, 11, 12, 13, 20, 21, 22, 23, 24, 25, 26).
This protein serves as the 'glue' that holds the fetal membranes down to the uterus, and women who have excessive leakage of this protein into the cervicovaginal discharge are at risk of delivering early.
In species such as humans and rodents, the fetal membranes invade, or implant, into the submucosa of the uterine epithelium.
Two or more of these processes often occur simultaneously, ultimately converging on a final common biochemical pathway that leads to degradation of the extracellular matrix in the cervix and fetal membranes and activation of the uterine myometrium.