| placenta extrachorales | A placenta in which the chorionic plate is limited by a thin membranous fold at the edge. (05 Mar 2000) |
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| placenta fenestrata | A placenta in which there are areas of thinning, sometimes extending to entire absence of placental tissue. (05 Mar 2000) |
| placenta gonadotropin | A glycoprotein with a carbohydrate fraction composed of d-galactose and hexosamine, extracted from the urine of pregnant women and produced by the placental trophoblastic cells; its most important role appears to be stimulation, during the first trimester, of ovarian secretion of the oestrogen and progesterone required for the integrity of conceptus; it appears to play no significant role in the last two trimesters of pregnancy, as the oestrogen and progesterone are then formed by the placenta. Synonym: anterior pituitary-like hormone, choriogonadotropin, chorionic gonadotropic hormone, chorionic gonadotrophic hormone, placenta gonadotropin, placentagonadotropin. (05 Mar 2000) |
| placenta increta | A form of placenta accreta in which the chorionic villi invade the myometrium. (05 Mar 2000) |
| placenta, low | Location of the placenta in the lower part of the uterus (womb) so that the placenta partially or completely covers the cervix. Also known as a placenta previa. (12 Dec 1998) |
| placenta marginata | A placenta with raised edges, less pronounced than the placenta circumvallata. See: placenta reflexa. (05 Mar 2000) |
| placenta membranacea | An abnormally thin placenta covering an unusually large area of the uterine lining. Synonym: placenta diffusa. (05 Mar 2000) |
| placenta multiloba | A placenta having more than three lobes separated from each other by simple constrictions, the foetus being single. Synonym: placenta multipartita. (05 Mar 2000) |
| placenta multipartita | A placenta having more than three lobes separated from each other by simple constrictions, the foetus being single. Synonym: placenta multipartita. (05 Mar 2000) |
| placenta panduraformis | A form of placenta dimidiata with the two halves placed side by side in a shape suggestive of a lutelike musical instrument (pandura). (05 Mar 2000) |
| placenta percreta | The placenta invades the uterine wall. In placenta percreta, the chorionic villi (the vascular processes of the chorion, a foetal membrane that enters into the formation of the placenta) may invade the full thickness of the myometrium (the muscular portion of the uterus) causing an incomplete rupture of the uterus. Or the chorionic villi can go right on through the myometrium and serosa (the outside covering of the uterus) causing complete rupture of the uterus, a catastrophe. (12 Dec 1998) |
| placenta praevia | A placenta implanted near the outlet of the uterus so that at the time of delivery the placenta would precede (be previous to) the baby. Causes painless bleeding in the last third of pregancy. One reason for a c-section. (12 Dec 1998) |
| placenta previa | <obstetrics> The anatomic positioning of the placenta over the cervical os (opening to the birth canal). This is an important cause of painless third trimester bleeding in the pregnant female. Many cases of placenta previa will require cesarean section delivery. (31 Dec 1997) |
| placenta previa centralis | Placenta previa in which the placenta entirely covers the internal os of the cervix. Synonym: central placenta previa, total placenta previa. (05 Mar 2000) |
| placenta previa marginalis | Placenta previa in which the placenta comes to the margin of, but does not occlude, the internal os of the cervix. (05 Mar 2000) |