retained placenta


Also found in: Dictionary, Thesaurus, Encyclopedia.

re·tained pla·cen·ta

incomplete separation of the placenta and its failure to be expelled at the usual time after delivery of the child.

retained placenta

[ritānd′]
Etymology: L, retinere, to hold, placenta, flat cake
the failure of the placenta to be delivered during an appropriate period, usually 30 minutes, following birth of the infant.

re·tained pla·cen·ta

(rē-tānd plă-sentă)
Incomplete separation of the placenta and its failure to be expelled at the usual time after delivery of the child.

placenta

pl. placentae, placentas [L.] an organ characteristic of true mammals during pregnancy, joining mother and offspring, providing endocrine secretion and selective exchange of soluble bloodborne substances through apposition of uterine and trophoblastic vascularized parts. Called also afterbirth. See also fetal membranes, placentation.
Domestic animals have a chorioallantoic placenta in which the outer layer of the allantois is fused with the chorion and the fetal umbilical vessels are distributed in the connective tissue between the two. Placentae are classified in several ways; based on the tissues of the dam and the fetus that contact each other; based on the proportion of the surface area of the fetal membranes that is in fact placentacious; based on loss of tissue at birth, etc. Thus the bovine placenta is epitheliochorial, cotyledonary and nondeciduate.
The major function of the placenta is to allow diffusion of nutrients from the dam's blood into the fetus's blood and diffusion of waste products from the fetus back to the dam. This two-way exchange takes place across the placental membrane, which is semipermeable. The placenta also produces hormones such as progesterone and estrogen.

choriovitelline placenta
a placentation in which the yolk sac becomes involved in the fetal-maternal union.
cotyledonary placenta
distribution of the villi on the fetal chorion is localized in multiple circumscribed areas—the cotyledons.
Enlarge picture
Cotyledonary placenta of ruminants. By permission from Sack W, Wensing CJG, Dyce KM, Textbook of Veterinary Anatomy, Saunders, 2002
diffuse placenta
the villi on the fetal chorion is diffuse over the entire placenta as in mares and sows.
discoid placenta
a placenta in which the chorionic villi are arranged in a circular plate as in human and rodent placentae.
endotheliochorial placenta
the maternal vessels in the endometrium are bared to their endothelium and these are in contact with the chorion of the fetal membranes. This occurs in the bitch and queen.
epitheliochorial placenta
the uterine epithelium of the uterus and the chorion are in contact in this placentation, and there is no erosion of the epithelium. Characteristic of cows, sows and mares. Called also adeciduate placenta.
hemochorial placenta
a type of placenta in which all maternal layers are lost so that fetal tissue is in contact with frank maternal blood, as occurs in insectivores, rodents, rabbits and most primates.
nondeciduate placenta
no maternal tissue is lost when the pregnancy terminates.
retained placenta
the placenta has not been passed within 12 hours after the fetus has been delivered. Represents a potential beginning for metritis and infertility. Often difficult to assess in carnivores which rapidly eat the placenta.
syndesmochorial placenta
a type of placentation characterized by an endometrial attachment to the chorion with a limited amount of destruction of the endometrial epithelium. Formerly thought to be characteristic of the ewe and goat doe, these species are now known to have epitheliochorial placentae.
zonary placenta
a placenta in which the chorionic villi are restricted to an equatorial girdle, as in the bitch and queen.

retained

kept in an original position when dehiscence or movement to another location is more appropriate.

retained cartilage core
see retained enchondral cartilage cores.
retained corpus luteum
the corpus luteum is not resorbed at the appropriate time in the reproductive cycle and the animal remains anestral.
retained meconium
see meconium ileus.
retained placenta
see retained placenta.
retained testicle
failure of the testicle(s) to migrate out of the peritoneal cavity, through the inguinal ring and into the scrotum before the animal reaches puberty. The retention may be uni- or bilateral.
References in periodicals archive ?
Prophylactic antibiotics for manual removal of retained placenta in vaginal birth.
There were no significant differences in the occurrence of retained placenta, metritis, endometritis, ketosis, mastitis and udder edema due to DCAD treatments.
We found length TSL and retained placenta in the infusion group was more than bolus group significantly and average reduction in hemoglobin concentration levels for the bolus group was less than infusion group.
Lesson Retained placenta and/or sepsis: * spinal anaesthesia only if resuscitated and stable * if operation is required immediately, GA using cardiostable anaesthetic agents.
Less severe cases show poor growth rates and ill-thrift, adults show reduced fertility and retained placenta.
The mean time to placental delivery did not differ significantly between the two groups, but significantly more women in the saline group than in the oxytocin group had a retained placenta after 15 minutes (5 vs.
Metabolic and nutritional disorders such as ketosis, milk fever, retained placenta, and displaced abomasum (DA) all have their root cause in the nutritional management during the months leading up to calving (the dry cow period).
Retained placenta in mares can cause serious complications--including founder (laminitis) and severe uterine infections--and requires veterinary attention.
pregnancy-induced hypertension, placenta previa, retained placenta, and thromboembolism).