Search results
Results from the WOW.Com Content Network
Placenta praevia or placenta previa is when the placenta attaches inside the uterus but in a position near or over the cervical opening. [1] Symptoms include vaginal bleeding in the second half of pregnancy. [1] The bleeding is bright red and tends not to be associated with pain. [1]
There are three types of vasa praevia. In Type 1, there is a velamentous insertion with vessels crossing the cervix. In Type 2, the placenta is bilobed or has a succenturiate lobe, with unprotected vessels between the lobes. In Type 3, a portion of the placenta overlying the cervix has atrophied, leaving vessels at a margin exposed. [3]
This can lead to fetal malformations [2] [24] and low birth weight. [ 2 ] [ 6 ] [ 10 ] The umbilical vessels may also be longer compared to normal, [ 2 ] particularly when the site of velamentous cord insertion is in the lower uterine section as the extension of the uterine isthmus as pregnancy advances causes vessel elongation. [ 3 ]
Placenta previa is a condition that occurs when the placenta fully or partially covers the cervix. [13] Placenta previa can be further categorized into complete previa, partial previa, marginal previa, and low-lying placenta, depending on the degree to which the placenta covers the internal cervical os.
True cervical pregnancies tend to abort; if, however, the pregnancy is located higher in the canal and the placenta finds support in the uterine cavity, it can go past the first trimester. With the placenta being implanted abnormally, extensive vaginal bleeding can be expected at time of delivery and placental removal.
Besides placenta previa and placental abruption, uterine rupture can occur, which is a very serious condition leading to internal or external bleeding. Bleeding from the fetus is rare, but may occur with two conditions called vasa previa and velamentous umbilical cord insertion where the fetal blood vessels lie near the placental insertion site unprotected by Wharton's jelly of the cord. [11]
Ischemic placental disease leads to the attachment of the placenta to the uterine wall to become under-perfused, causing uteroplacental ischemia. Where the term overarches the pathology associated with preeclampsia , placental abruptions and intrauterine growth restriction (IUGR). [ 3 ]
Placenta accreta spectrum (PAS) is a medical condition that occurs when all or part of the placenta attaches abnormally to the myometrium (the muscular layer of the uterine wall) during pregnancy. This condition was first documented in medical literature in 1927 [ 1 ] .