A placental disease is any disease, disorder, or pathology of the
placenta
The placenta is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas and waste exchange between the physically separate mate ...
.
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
Pre-eclampsia is a disorder of pregnancy characterized by the onset of high blood pressure and often a significant amount of protein in the urine. When it arises, the condition begins after 20 weeks of pregnancy. In severe cases of the disease ...
, placental abruptions and
intrauterine growth restriction
Intrauterine growth restriction (IUGR), or fetal growth restriction, refers to poor growth of a fetus while in the womb during pregnancy. IUGR is defined by clinical features of malnutrition and evidence of reduced growth regardless of an infant's ...
(IUGR).
These factors are known to be the primary pathophysiology cause placental disease. Which is considered to be associated with more than half of premature births.
Abnormalities present within the spiral arteries lead to higher velocities in blood, in turn causes the maternal villi to shred.
Which trigger pro-coagulator molecules to be released into the blood stream causing action of the coagulator cascade, eventually leading to placental infarction.
Risk factors such as diabetes, chronic blood pressure and multiple pregnancies can increase the risk of developing placental disease.
Also, exposure to sudden trauma can increase the risk of placental abruption which coincides with placental disease.
There is no target treatment available for placental disease. Associative prevention mechanisms can be a method of minimising the risk of developing the disease, within early stages of pregnancy.
Placental syndromes include pregnancy loss, fetal growth restriction, preeclampsia, preterm delivery, premature rupture of membranes, placental abruption and intrauterine fetal demise.
Signs and symptoms
The abnormal spiral arteries lead decreased level of oxygen diffusion through the placental villus,
which cause chronic hypoxia. The abnormal trophoblast invasion,
lead to overall uteroplacental insufficiencies and uteroplacental underperfusion. It is due to the decreased vascularisation, there are reduced levels of nutrient delivery to the foetus.
Also, cases of still births can be associated with placental disease.
Causes
Preeclampsia is considered to be linked with Placental Disease, as well as intrauterine growth restriction (IUGR) and placental abruptions are risk factors that lead to placental disease.
Especially when these symptoms are evident at early stages of pregnancy.
The abnormal invasion of the trophoblast cells, lack of important growth factors such as vascular endothelial growth factor (VEGF) and placental growth factor (PlGF), has an association with the onset of placental disease.
Risk factors
Risk factors associated with placental disease are as follows:
* Smoking cigarettes and use other forms of drugs such as cocaine.
* Diabetes mellitus
* Maternal age less than 20 years or over the age of 35
* Multiple pregnancies
* Chronic high blood pressure
* Being underweight or obese
Also, chronic renal disease, collagen vascular disease, thrombophilia, and cardiovascular disease increase the risk of developing placental disease.
Moreover, being exposed to severe trauma within the pregnancy period, rapid acceleration and deceleration and uterine compression increase the risk of placental abruption, in turn leading to placental disease.
Adherence/penetration
*
Abruptio placentae
*
Placenta accreta
Placenta accreta occurs when all or part of the placenta attaches abnormally to the '' myometrium'' (the muscular layer of the uterine wall). Three grades of abnormal placental attachment are defined according to the depth of attachment and invas ...
*
Placenta increta
*
Placenta percreta
Placenta accreta occurs when all or part of the placenta attaches abnormally to the ''myometrium'' (the muscular layer of the uterine wall). Three grades of abnormal placental attachment are defined according to the depth of attachment and invasi ...
Inflammatory/infectious
*
Placentitis
Placentitis is an inflammation of the placenta. The main forms of placentitis are:
*Villitis, inflammation of chorionic villi.
*Intervillositis, inflammation of the intervillous space.
It may be caused by vertically transmitted infections.
Bec ...
:*
Villitis of unknown etiology
Villitis of unknown etiology (VUE), also known as chronic villitis, is a placental injury. VUE is an inflammatory condition involving the chorionic villi (placental villi). VUE is a recurrent condition and can be associated with intrauterine grow ...
:*
TORCH infections
Placental development
*
Circumvallate placenta
*
Placental villous immaturity
Obstruction of os
*
Placenta previa
Placenta praevia is when the placenta attaches inside the uterus but in a position near or over the cervical opening. Symptoms include vaginal bleeding in the second half of pregnancy. The bleeding is bright red and tends not to be associated wi ...
*
Vasa previa
Vasa praevia is a condition in which fetal blood vessels cross or run near the internal opening of the uterus. These vessels are at risk of rupture when the supporting membranes rupture, as they are unsupported by the umbilical cord or placental ...
Vascular
*
Fetal thrombotic vasculopathy
*
Hypertrophic decidual vasculopathy
In pathology, hypertrophic decidual vasculopathy, abbreviated HDV, is the histomorphologic correlate of gestational hypertension, as may be seen in intrauterine growth restriction (IUGR) and HELLP syndrome.
The name of the condition describes ...
*
Chorangiosis
*
Chorangioma
*
Placental infarction
Neoplastic
Trophoblastic neoplasms derive from trophoblastic tissue. Examples include:
*
Choriocarcinoma
Choriocarcinoma is a malignant, trophoblastic cancer, usually of the placenta. It is characterized by early hematogenous spread to the lungs. It belongs to the malignant end of the spectrum in gestational trophoblastic disease (GTD). It is also c ...
*
Hydatidiform mole
Mechanism
In placental disease, there's abnormalities present within the spiral arties of the uterus, where the terminal part of the spinal arteries does not dilate. This leads to decrease oxygen carried past the maternal villi into the intervillus space. The lack of terminal dilation and inclining blood velocity causes shredding of the villi into the maternal blood, releasing blood coagulants activating the coagulation cascade. Which then leads to blocking of the blood vessels causing placental infarction.
Diagnosis
Placental Disease can be diagnosed through technologies such as, Prenatal ultrasound evaluation and invasive foetal testing. The size of the foetus is taken into account through ultrasonography in terms of intrauterine growth restriction (IUGR). In conjunction with taking into account the maternal history.
Suspicions may be confirmed by postpartum examination of the placenta.
Prevention
The following factors can be linked with reducing the likelihood of developing placental disease:
*Use of aspirin, can reduce the risks associated with preeclampsia
*Low calcium intake can reduce the risk of preeclampsia
*Reducing oxidative stress present within the body
*Intake of prenatal multivitamins
Treatment
Treatment of placental disease would require a premature birth, in order to avoid a still birth.
Epidemiology
Placental disease is more common in preterm gestation than with full term.
Which leads to serious injuries to both the mother and the new-born.
Women who endured placental disease within the first pregnancy has an increased risk of the disease progressing within future pregnancies.
The onset of the disease within the first trimester leads to preterm delivery of a premature baby.
Preeclampsia is diagnosed in 3-5% of pregnancies that place them at risk of developing placental disease.
Ischemic placental disease is linked with approximately more than half of premature births.
References
External links
{{Certain conditions originating in the perinatal period
Complications of labour and delivery